{"id":233,"date":"2021-12-17T21:43:00","date_gmt":"2021-12-17T21:43:00","guid":{"rendered":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/3-minerals\/"},"modified":"2022-05-18T14:11:26","modified_gmt":"2022-05-18T14:11:26","slug":"3-minerals","status":"publish","type":"chapter","link":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/3-minerals\/","title":{"raw":"3 Minerals","rendered":"3 Minerals"},"content":{"raw":"[caption id=\"attachment_2752\" align=\"aligncenter\" width=\"1024\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Cristales_cueva_de_Naica.jpg\"><img class=\"wp-image-2752 size-large\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/Cristales_cueva_de_Naica-1024x683-1.jpg\" alt=\"The crystals are huge!\" width=\"1024\" height=\"683\"><\/a> These selenite (gypsum) crystals, found in The Cave of the Crystals in Naica, Mexico, has some of the largest minerals ever found. The largest crystal found here is 39 feet (12 meters) and 55 tones.[\/caption]\n<h1>3 Minerals<\/h1>\n<strong>KEY<\/strong><b> CONCEPTS<\/b>\n\n<b>At the end of this chapter, students should be able to:<\/b>\n<ul>\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Define [pb_glossary id=\"1765\"]mineral[\/pb_glossary].<\/span><\/li>\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Describe the basic structure of the atom.<\/span><\/li>\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Derive basic atomic information from the Periodic Table of [pb_glossary id=\"1778\"]Elements[\/pb_glossary].<\/span><\/li>\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Describe chemical [pb_glossary id=\"1781\"]bonding[\/pb_glossary] related to [pb_glossary id=\"1765\"]minerals[\/pb_glossary].<\/span><\/li>\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Describe the main ways [pb_glossary id=\"1765\"]minerals[\/pb_glossary] form.<\/span><\/li>\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Describe the [pb_glossary id=\"1788\"]silicon-oxygen tetrahedron[\/pb_glossary] and how it forms common [pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary].<\/span><\/li>\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">List common non-[pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] in [pb_glossary id=\"971\"]oxide[\/pb_glossary], [pb_glossary id=\"973\"]sulfide[\/pb_glossary], [pb_glossary id=\"974\"]sulfate[\/pb_glossary], and [pb_glossary id=\"969\"]carbonate[\/pb_glossary] groups.<\/span><\/li>\n \t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Identify [pb_glossary id=\"1765\"]minerals[\/pb_glossary] using physical properties and identification tables. <\/span><\/li>\n<\/ul>\nThe term \u201c[pb_glossary id=\"1765\"]minerals[\/pb_glossary]\u201d as used in nutrition labels and pharmaceutical products is not the same as a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] in a geological sense. In geology, the classic definition of a <strong>[pb_glossary id=\"1765\"]mineral[\/pb_glossary]<\/strong> is: 1) naturally occurring, 2) inorganic, 3) solid at room [pb_glossary id=\"1767\"]temperature[\/pb_glossary], 4) regular crystal structure, and 5) defined chemical [pb_glossary id=\"1909\"]composition[\/pb_glossary]. Some natural substances technically should not be considered [pb_glossary id=\"1765\"]minerals[\/pb_glossary], but are included by exception. For example, water and mercury are liquid at room [pb_glossary id=\"1767\"]temperature[\/pb_glossary]. Both are considered [pb_glossary id=\"1765\"]minerals[\/pb_glossary] because they were classified before the room-[pb_glossary id=\"1767\"]temperature[\/pb_glossary] rule was accepted as part of the definition. [pb_glossary id=\"970\"]Calcite[\/pb_glossary] is quite often formed by organic processes, but is considered a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] because it is widely found and geologically important. Because of these discrepancies, the International Mineralogical Association in 1985 amended the definition to: \u201cA [pb_glossary id=\"1765\"]mineral[\/pb_glossary] is an [pb_glossary id=\"1778\"]element[\/pb_glossary] or chemical compound that is normally crystalline and that has been formed as a result of geological processes.\u201d This means that the [pb_glossary id=\"970\"]calcite[\/pb_glossary] in the shell of a clam is not considered a [pb_glossary id=\"1765\"]mineral[\/pb_glossary]. But once that clam shell undergoes burial, [pb_glossary id=\"1905\"]diagenesis[\/pb_glossary], or other geological processes, then the [pb_glossary id=\"970\"]calcite[\/pb_glossary] is considered a [pb_glossary id=\"1765\"]mineral[\/pb_glossary]. Typically, substances like [pb_glossary id=\"1934\"]coal[\/pb_glossary], pearl, opal, or [pb_glossary id=\"999\"]obsidian[\/pb_glossary] that do not fit the definition of [pb_glossary id=\"1765\"]mineral[\/pb_glossary] are called mineraloids.\n\nA <strong>rock<\/strong> is a substance that contains one or more [pb_glossary id=\"1765\"]minerals[\/pb_glossary] or mineraloids. As is discussed in later chapters, there are three types of rocks [pb_glossary id=\"1909\"]composed[\/pb_glossary] of [pb_glossary id=\"1765\"]minerals[\/pb_glossary]: [pb_glossary id=\"1753\"]igneous[\/pb_glossary] (rocks crystallizing from molten material), sedimentary (rocks [pb_glossary id=\"1909\"]composed[\/pb_glossary] of products of [pb_glossary id=\"251\"]mechanical weathering[\/pb_glossary] (sand, gravel, etc.) and [pb_glossary id=\"1890\"]chemical weathering[\/pb_glossary] (things [pb_glossary id=\"1785\"]precipitated[\/pb_glossary] from [pb_glossary id=\"1783\"]solution[\/pb_glossary]), and [pb_glossary id=\"1992\"]metamorphic[\/pb_glossary] (rocks produced by alteration of other rocks by heat and pressure.\n<h2><span style=\"font-weight: 400\">3.1 Chemistry of Minerals<\/span><\/h2>\nRocks are [pb_glossary id=\"1909\"]composed[\/pb_glossary] of [pb_glossary id=\"1765\"]minerals[\/pb_glossary] that have a specific chemical [pb_glossary id=\"1909\"]composition[\/pb_glossary].\u00a0 To understand [pb_glossary id=\"1765\"]mineral[\/pb_glossary] chemistry, it is essential to examine the fundamental unit of all matter, the atom.\n<h3><b>3.1.1 The Atom<\/b><\/h3>\n[caption id=\"attachment_2753\" align=\"alignright\" width=\"283\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.1-Electron_cloud_model_of_atom.jpg\"><img class=\"size-medium wp-image-2753\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/03.1-Electron_cloud_model_of_atom-283x300-1.jpg\" alt=\"Image of atom with defined nucleus and electrons surrounding it in a cloud with concentrations of electrons in energy shells\" width=\"283\" height=\"300\"><\/a> Electron cloud model of the atom[\/caption]\n\nMatter is made of atoms. Atoms consists of subatomic particles\u2014<strong>protons<\/strong>, <strong>neutrons<\/strong>, and <strong>electrons<\/strong>. A simple model of the atom has a central nucleus [pb_glossary id=\"1909\"]composed[\/pb_glossary] of protons, which have positive charges, and neutrons which have no charge. A cloud of negatively charged electrons surrounds the nucleus, the number of electrons equaling the number of protons thus balancing the positive charge of the protons for a neutral atom. Protons and neutrons each have a mass number of 1. The mass of an electron is less than\u00a01\/1000<sup>th<\/sup>\u00a0that of a proton or neutron, meaning most of the atom\u2019s mass is in the nucleus.\n<h3><b>3.1.2 Periodic Table of the Elements<\/b><\/h3>\nMatter is [pb_glossary id=\"1909\"]composed[\/pb_glossary] of [pb_glossary id=\"1778\"]elements[\/pb_glossary] which are atoms that have a specific number of protons in the nucleus. This number of protons is called the <strong>Atomic Number<\/strong> for the [pb_glossary id=\"1778\"]element[\/pb_glossary]. For example, an oxygen atom has 8 protons and an iron atom has 26 protons. An [pb_glossary id=\"1778\"]element[\/pb_glossary] cannot be broken down chemically into a simpler form and retains unique chemical and physical properties. Each [pb_glossary id=\"1778\"]element[\/pb_glossary] behaves in a unique manner in nature. This uniqueness led scientists to develop a periodic table of the [pb_glossary id=\"1778\"]elements[\/pb_glossary], a tabular arrangement of all known [pb_glossary id=\"1778\"]elements[\/pb_glossary] listed in order of their atomic number.\n\n[caption id=\"attachment_2754\" align=\"aligncenter\" width=\"1024\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Periodic_Table-02-scaled.jpg\"><img class=\"size-large wp-image-2754\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/Periodic_Table-02-1024x795-1.jpg\" alt=\"The Periodic Table of the Elements showing all elements with their chemical symbols, atomic weight, and atomic number.\" width=\"1024\" height=\"795\"><\/a> The Periodic Table of the Elements[\/caption]\n\n&nbsp;\n\n<span style=\"font-weight: 400\">The first arrangement of [pb_glossary id=\"1778\"]elements[\/pb_glossary] into a periodic table was done by Dmitri Mendeleev in 1869 using the [pb_glossary id=\"1778\"]elements[\/pb_glossary] known at the time<\/span><span style=\"font-weight: 400\">. In the periodic table, each [pb_glossary id=\"1778\"]element[\/pb_glossary] has a chemical symbol, name, atomic number, and atomic mass. The chemical symbol is an abbreviation for the [pb_glossary id=\"1778\"]element[\/pb_glossary], often derived from a Latin or Greek name for the substance<\/span><span style=\"font-weight: 400\">. The atomic number is the number of protons in the nucleus. The atomic mass is the number of protons and neutrons in the nucleus, each with a mass number of one. Since the mass of electrons is so much less than the protons and neutrons, the atomic mass is effectively the number of protons plus neutrons. <\/span>\n\n[caption id=\"attachment_2755\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.3a_Formation_of_Carbon14_from_Nitrogen14.jpg\"><img class=\"size-medium wp-image-2755\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/3.3a_Formation_of_Carbon14_from_Nitrogen14-300x123-1.jpg\" alt=\"\" width=\"300\" height=\"123\"><\/a> Formation of Carbon 14 from Nitrogen 14[\/caption]\n\nThe atomic mass of natural [pb_glossary id=\"1778\"]elements[\/pb_glossary] represents an average mass of the atoms comprising that substance in nature and is usually not a whole number as seen on the periodic table, meaning that an [pb_glossary id=\"1778\"]element[\/pb_glossary] exists in nature with atoms having different numbers of neutrons. The differing number of neutrons affects the mass of an [pb_glossary id=\"1778\"]element[\/pb_glossary] in nature and the atomic mass number represents this average. This gives rise to the concept of\u00a0[pb_glossary id=\"1779\"]isotope[\/pb_glossary]<strong>.\u00a0<\/strong><strong>[pb_glossary id=\"1779\"]Isotopes[\/pb_glossary] <\/strong>are forms of an [pb_glossary id=\"1778\"]element[\/pb_glossary] with the same number of protons but different numbers of neutrons. There are usually several [pb_glossary id=\"1779\"]isotopes[\/pb_glossary] for a particular [pb_glossary id=\"1778\"]element[\/pb_glossary]. For example, 98.9% of carbon atoms have 6 protons and 6 neutrons. This [pb_glossary id=\"1779\"]isotope[\/pb_glossary] of carbon is called carbon-12 (<sup>12<\/sup>C). A few carbon atoms, carbon-13 (<sup>13<\/sup>C), have 6 protons and 7 neutrons. A trace amount of carbon atoms, carbon-14 (<sup>14<\/sup>C), has 6 protons and 8 neutrons.\n\n[caption id=\"attachment_2756\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/elemental-composition-crust.jpg\"><img class=\"size-medium wp-image-2756\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/elemental-composition-crust-300x277-1.jpg\" alt=\"Oxygen and silicon make up 3\/4ths of the chart.\" width=\"300\" height=\"277\"><\/a> Element abundance pie chart for Earth's crust by Callan Bentley.[\/caption]\n\nAmong the 118 known [pb_glossary id=\"1778\"]elements[\/pb_glossary], the heaviest are fleeting human creations known only in high energy particle accelerators, and they decay rapidly. The heaviest naturally occurring [pb_glossary id=\"1778\"]element[\/pb_glossary] is uranium, atomic number 92. The eight most abundant elements in Earth\u2019s [pb_glossary id=\"1653\"]continental crust[\/pb_glossary] are shown in Table 1<span style=\"font-weight: 400\">. These [pb_glossary id=\"1778\"]elements[\/pb_glossary] are found in the most common rock forming [pb_glossary id=\"1765\"]minerals[\/pb_glossary].<\/span>\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n<table style=\"height: 135px\">\n<tbody>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><b>[pb_glossary id=\"1778\"]Element[\/pb_glossary]<\/b><\/td>\n<td style=\"height: 15px;width: 134.797px\"><b>Symbol<\/b><\/td>\n<td style=\"height: 15px;width: 237.703px\"><b>Abundance %<\/b><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Oxygen<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">O<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">47%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Silicon<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Si<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">28%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Aluminum<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Al<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">8%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Iron<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Fe<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">5%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Calcium<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Ca<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">4%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Sodium<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Na<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">3%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Potassium<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\">K<\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">3%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Magnesium<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\">Mg<\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">2%<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<em style=\"font-size: 16px;font-weight: 400\">Table 1. Eight Most Abundant [pb_glossary id=\"1778\"]Elements[\/pb_glossary] in the Earth\u2019s [pb_glossary id=\"1653\"]Continental Crust[\/pb_glossary] % by weight (source:\u00a0<a href=\"https:\/\/pubs.usgs.gov\/circ\/1953\/0285\/report.pdf\">USGS<\/a>). All other [pb_glossary id=\"1778\"]elements[\/pb_glossary] are less than 1%.<\/em>\n<h3><b>3.1.3 Chemical Bonding<\/b><\/h3>\n[caption id=\"attachment_2757\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/H2O_2D_labelled.svg_.png\"><img class=\"wp-image-145 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/H2O_2D_labelled.svg_-300x131.png\" alt=\"The hydrogen atoms are on one side, about 105\u00b0 apart.\" width=\"300\" height=\"131\"><\/a> A model of a water molecule, showing the bonds between the hydrogen and oxygen.[\/caption]\n\n&nbsp;\n\n<span style=\"font-weight: 400\">Most substances on Earth are compounds containing multiple [pb_glossary id=\"1778\"]elements[\/pb_glossary]. Chemical [pb_glossary id=\"1781\"]bonding[\/pb_glossary] describes how these atoms attach with each other to form compounds, such as sodium and chlorine combining to form NaCl, common table salt. Compounds that are held together by\u00a0<\/span>chemical [pb_glossary id=\"1781\"]bonds[\/pb_glossary] are called molecules. Water is a compound of hydrogen and oxygen in which two hydrogen atoms are covalently [pb_glossary id=\"1781\"]bonded[\/pb_glossary] with one oxygen making the water molecule. The oxygen we breathe is formed when one oxygen atom covalently [pb_glossary id=\"1781\"]bonds[\/pb_glossary] with another oxygen atom to make the molecule O<sub>2<\/sub>. The subscript 2 in the chemical formula indicates the molecule contains two atoms of oxygen.\n\nMost [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are also compounds of more than one [pb_glossary id=\"1778\"]element[\/pb_glossary]. The common [pb_glossary id=\"1765\"]mineral[\/pb_glossary] [pb_glossary id=\"970\"]calcite[\/pb_glossary] has the chemical formula CaCO<sub>3<\/sub> indicating the molecule consists of one calcium, one carbon, and three oxygen atoms.\u00a0In [pb_glossary id=\"970\"]calcite[\/pb_glossary], one carbon and three oxygen atoms are held together by covalent [pb_glossary id=\"1781\"]bonds[\/pb_glossary] to form a <strong>molecular [pb_glossary id=\"2449\"]ion[\/pb_glossary]<\/strong>, called [pb_glossary id=\"969\"]carbonate[\/pb_glossary], which has a negative charge. Calcium as an <strong>[pb_glossary id=\"2449\"]ion[\/pb_glossary]<\/strong> has a positive charge of plus two. The two oppositely charged ions attract each other and combine to form the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] [pb_glossary id=\"970\"]calcite[\/pb_glossary], CaCO3. The name of the chemical compound is calcium [pb_glossary id=\"969\"]carbonate[\/pb_glossary], where calcium is Ca and [pb_glossary id=\"969\"]carbonate[\/pb_glossary] refers to the molecular [pb_glossary id=\"2449\"]ion[\/pb_glossary] CO<sub>3<\/sub><sup>-2<\/sup>.\n\nThe [pb_glossary id=\"1765\"]mineral[\/pb_glossary] [pb_glossary id=\"1789\"]olivine[\/pb_glossary] has the chemical formula (Mg,Fe)<sub>2<\/sub>SiO<sub>4<\/sub>, in which one silicon and four oxygen atoms are [pb_glossary id=\"1781\"]bonded[\/pb_glossary] with two atoms of either magnesium or iron.\u00a0The comma between iron (Fe) and magnesium (Mg) indicates the two [pb_glossary id=\"1778\"]elements[\/pb_glossary] can occupy the same location in the crystal structure and substitute for one another.\n<h4><i><span style=\"font-weight: 400\">3.1.3.1 Valence and Charge<\/span><\/i><\/h4>\n<span style=\"font-weight: 400\">The electrons around the atom\u2019s nucleus are located in shells representing different energy levels. The outermost shell is called the <strong>valence shell<\/strong>. Electrons in the valence shell are involved in chemical [pb_glossary id=\"1781\"]bonding[\/pb_glossary]. In 1913, Niels Bohr proposed a simple model of the atom that states atoms are more stable when their outermost shell is full<\/span><span style=\"font-weight: 400\">. Atoms of most [pb_glossary id=\"1778\"]elements[\/pb_glossary] thus tend to gain or lose electrons so the outermost or valence shell is full. In Bohr\u2019s model, the innermost shell can have a maximum of two electrons and the second and third shells can have a maximum of eight electrons. <\/span>When the innermost shell is the valence shell, as in the case of hydrogen and helium, it obeys the [pb_glossary id=\"2439\"]octet rule[\/pb_glossary] when it is full with two electrons. For [pb_glossary id=\"1778\"]elements[\/pb_glossary] in higher rows, the [pb_glossary id=\"2439\"]octet rule[\/pb_glossary] of eight electrons in the valence shell applies.\n\n[caption id=\"attachment_2758\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.4_Carbon_dioxide_3D_ball.png\"><img class=\"wp-image-2758 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.4_Carbon_dioxide_3D_ball-300x213-1.png\" alt=\"Carbon dioxide molecule with a carbon ion in the center and two oxygen ions on either side, each sharing two electrons with the carbon.\" width=\"300\" height=\"213\"><\/a> The carbon dioxide molecule. Since Oxygen is -2 and Carbon is +4, the two oxygens bond to the carbon to form a neutral molecule.[\/caption]\n\nThe rows in the periodic table present the [pb_glossary id=\"1778\"]elements[\/pb_glossary] in order of atomic number and the columns organize [pb_glossary id=\"1778\"]elements[\/pb_glossary] with similar characteristics, such as the same number of electrons in their valence shells. Columns are often labeled from left to right with Roman numerals I to VIII, and Arabic numerals 1 through 18. The [pb_glossary id=\"1778\"]elements[\/pb_glossary] in columns I and II have 1 and 2 electrons in their respective valence shells and the [pb_glossary id=\"1778\"]elements[\/pb_glossary] in columns VI and VII have 6 and 7 electrons in their respective valence shells.\n\n<span style=\"font-weight: 400\">In row 3 and column I, sodium (Na) has 11 protons in the nucleus and 11 electrons in three shells\u20142 electrons in the inner shell, 8 electrons in the second shell, and 1 electron in the valence shell. To maintain a full outer shell of 8 electrons per the [pb_glossary id=\"2439\"]octet rule[\/pb_glossary], sodium readily gives up that 1 electron so there are 10 total electrons. With 11 positively charged protons in the nucleus and 10 negatively charged electrons in two shells, sodium when forming chemical [pb_glossary id=\"1781\"]bonds[\/pb_glossary] is an [pb_glossary id=\"2449\"]ion[\/pb_glossary] with an overall net charge of +1<\/span><span style=\"font-weight: 400\">.<\/span>\n\n<span style=\"font-weight: 400\">All [pb_glossary id=\"1778\"]elements[\/pb_glossary] in column I have a single electron in their valence shell and a valence of 1.\u00a0<\/span>These other column I [pb_glossary id=\"1778\"]elements[\/pb_glossary] also readily give up this single valence electron and thus become ions with a +1 charge. [pb_glossary id=\"1778\"]Elements[\/pb_glossary] in column II readily give up 2 electrons and end up as ions with a charge of +2. Note that elements in columns I and II which readily give up their valence electrons, often form bonds with [pb_glossary id=\"1778\"]elements[\/pb_glossary] in columns VI and VII which readily take up these electrons. \u00a0[pb_glossary id=\"1778\"]Elements[\/pb_glossary] in columns 3 through 15 are usually involved in covalent [pb_glossary id=\"1781\"]bonding[\/pb_glossary]. The last column 18 (VIII) contains the <strong>noble gases<\/strong>. These [pb_glossary id=\"1778\"]elements[\/pb_glossary] are chemically inert because the valence shell is already full with 8 electrons, so they do not gain or lose electrons. An example is the noble gas helium which has 2 valence electrons in the first shell. Its valence shell is therefore full. All [pb_glossary id=\"1778\"]elements[\/pb_glossary] in column VIII possess full valence shells and do not form [pb_glossary id=\"1781\"]bonds[\/pb_glossary] with other [pb_glossary id=\"1778\"]elements[\/pb_glossary].\n\n<span style=\"font-weight: 400\">As seen above, an atom with a net positive or negative charge as a result of gaining or losing electrons is called an <strong>[pb_glossary id=\"2449\"]ion[\/pb_glossary]<\/strong>. In general the [pb_glossary id=\"1778\"]elements[\/pb_glossary] on the left side of the table lose electrons and become positive ions, called [pb_glossary id=\"1780\"]cations[\/pb_glossary] because they are attracted to the cathode in an electrical device. The [pb_glossary id=\"1778\"]elements[\/pb_glossary] on the right side tend to gain electrons. These are called [pb_glossary id=\"1782\"]anions[\/pb_glossary] because they are attracted to the anode in an electrical device. The [pb_glossary id=\"1778\"]elements[\/pb_glossary] in the center of the periodic table, columns 3 through 15, do not consistently follow the [pb_glossary id=\"2439\"]octet rule[\/pb_glossary]. These are called transition [pb_glossary id=\"1778\"]elements[\/pb_glossary]. A common example is iron, which has a +2 or +3 charge depending on the [pb_glossary id=\"1896\"]oxidation[\/pb_glossary] state of the [pb_glossary id=\"1778\"]element[\/pb_glossary]. Oxidized Fe<sup>+3<\/sup> carries a +3 charge and reduced Fe<sup>+2<\/sup> is +2. These two different [pb_glossary id=\"1896\"]oxidation[\/pb_glossary] states of iron often impart dramatic colors to rocks containing their [pb_glossary id=\"1765\"]minerals[\/pb_glossary]\u2014the oxidized form producing red colors and the reduced form producing green.<\/span>\n<h4><i><span style=\"font-weight: 400\">3.1.3.2\u00a0<\/span><\/i><i><span style=\"font-weight: 400\">Ionic Bonding<\/span><\/i><\/h4>\n[caption id=\"attachment_2759\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03-Sodium-chloride-3D-ionic.png\"><img class=\"size-medium wp-image-2759\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03-Sodium-chloride-3D-ionic-300x284-1.png\" alt=\"Image of crystal model of halite with ions of sodium and chlorine arranged in a cubic structure.\" width=\"300\" height=\"284\"><\/a> Cubic arrangement of Na and Cl in Halite[\/caption]\n\n&nbsp;\n\n<span style=\"font-weight: 400\">Ionic [pb_glossary id=\"1781\"]bonds[\/pb_glossary], also called electron-transfer [pb_glossary id=\"1781\"]bonds[\/pb_glossary], are formed by the electrostatic attraction between atoms having opposite charges. Atoms of two opposite charges attract each other electrostatically and form an <strong>ionic [pb_glossary id=\"1781\"]bond[\/pb_glossary]<\/strong> in which the positive [pb_glossary id=\"2449\"]ion[\/pb_glossary] transfers its electron (or electrons) to the negative [pb_glossary id=\"2449\"]ion[\/pb_glossary] which takes them up. Through this transfer both atoms thus achieve a full valence shell.\u00a0<\/span>For example one atom of sodium (Na<sup>+1<\/sup>) and one atom of chlorine (Cl<sup>-1<\/sup>) form an ionic [pb_glossary id=\"1781\"]bond[\/pb_glossary] to make the compound sodium chloride (NaCl). This is also known as the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] [pb_glossary id=\"1922\"]halite[\/pb_glossary] or common table salt. Another example is calcium (Ca<sup>+2<\/sup>) and chlorine (Cl<sup>-1<\/sup>) combining to make the compound calcium chloride (CaCl<sub>2<\/sub>). The subscript 2 indicates two atoms of chlorine are ionically [pb_glossary id=\"1781\"]bonded[\/pb_glossary] to one atom of calcium.\n<h4><i><span style=\"font-weight: 400\">3.1.3.3\u00a0<\/span><\/i><i><span style=\"font-weight: 400\">Covalent <\/span><\/i><i><span style=\"font-weight: 400\">Bonding<\/span><\/i><\/h4>\n[caption id=\"attachment_2760\" align=\"alignleft\" width=\"249\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Covalent.svg_.png\"><img class=\"size-medium wp-image-2760\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Covalent.svg_-249x300-1.png\" alt=\"Each atom is sharing electrons.\" width=\"249\" height=\"300\"><\/a> Methane molecule[\/caption]\n\n&nbsp;\n\nIonic [pb_glossary id=\"1781\"]bonds[\/pb_glossary] are usually formed between a <strong>metal<\/strong> and a <strong>nonmetal<\/strong>. Another type, called a covalent or electron-sharing [pb_glossary id=\"1781\"]bond[\/pb_glossary], commonly occurs between nonmetals. Covalent [pb_glossary id=\"1781\"]bonds[\/pb_glossary] share electrons between ions to complete their valence shells. For example, oxygen (atomic number 8) has 8 electrons\u20142 in the inner shell and 6 in the valence shell. Gases like oxygen often form diatomic molecules by sharing valence electrons. In the case of oxygen, two atoms attach to each other and share 2 electrons to fill their valence shells to become the common oxygen molecule we breathe (O<sub>2<\/sub>). Methane (CH<sub>4<\/sub>) is another covalently [pb_glossary id=\"1781\"]bonded[\/pb_glossary] gas. The carbon atom needs 4 electrons and each hydrogen needs 1. Each hydrogen shares its electron with the carbon to form a molecule as shown in the figure.\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"17\"]\n\n[caption id=\"attachment_3754\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.1-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-149\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 3.1 via this QR Code.[\/caption]\n<h2><span style=\"font-size: 28px\">3.2 Formation of Minerals<\/span><\/h2>\n<span style=\"font-weight: 400\">[pb_glossary id=\"1765\"]Minerals[\/pb_glossary] form when atoms [pb_glossary id=\"1781\"]bond[\/pb_glossary] together in a crystalline arrangement. Three main ways this occurs in nature are: 1) [pb_glossary id=\"1785\"]precipitation[\/pb_glossary] directly from an aqueous (water) [pb_glossary id=\"1783\"]solution[\/pb_glossary] with a [pb_glossary id=\"1767\"]temperature[\/pb_glossary] change, 2) [pb_glossary id=\"1752\"]crystallization[\/pb_glossary] from a [pb_glossary id=\"1750\"]magma[\/pb_glossary] with a [pb_glossary id=\"1767\"]temperature[\/pb_glossary] change, and 3) biological [pb_glossary id=\"1785\"]precipitation[\/pb_glossary] by the action of organisms. <\/span>\n<h3><b> 3.2.1 Precipitation from aqueous solution<\/b><\/h3>\n[caption id=\"attachment_2761\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.5_Hard_Water_Calcification.jpg\"><img class=\"size-medium wp-image-2761\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.5_Hard_Water_Calcification-300x200-1.jpg\" alt=\"Encrusted calcium carbonate (lime) deposits on faucent\" width=\"300\" height=\"200\"><\/a> Calcium carbonate deposits from hard water[\/caption]\n\n&nbsp;\n\n[pb_glossary id=\"1783\"]Solutions[\/pb_glossary] consist of ions or molecules, known as solutes, [pb_glossary id=\"1893\"]dissolved[\/pb_glossary] in a medium or solvent. In nature this solvent is usually water. Many [pb_glossary id=\"1765\"]minerals[\/pb_glossary] can be dissolved in water, such as [pb_glossary id=\"1922\"]halite[\/pb_glossary] or table salt, which has the [pb_glossary id=\"1909\"]composition[\/pb_glossary] sodium chloride, NaCl. The Na<sup>+1<\/sup> and Cl<sup>-1<\/sup> ions separate and disperse into the [pb_glossary id=\"1783\"]solution[\/pb_glossary].\n\n<strong>[pb_glossary id=\"1785\"]Precipitation[\/pb_glossary]<\/strong> is the reverse process, in which ions in [pb_glossary id=\"1783\"]solution[\/pb_glossary] come together to form solid [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. [pb_glossary id=\"1785\"]Precipitation[\/pb_glossary] is dependent on the concentration of ions in [pb_glossary id=\"1783\"]solution[\/pb_glossary] and other factors such as [pb_glossary id=\"1767\"]temperature[\/pb_glossary] and pressure. The point at which a solvent cannot hold any more solute is called [pb_glossary id=\"1784\"]saturation[\/pb_glossary]. [pb_glossary id=\"1785\"]Precipitation[\/pb_glossary] can occur when the [pb_glossary id=\"1767\"]temperature[\/pb_glossary] of the [pb_glossary id=\"1783\"]solution[\/pb_glossary] [pb_glossary id=\"2197\"]falls[\/pb_glossary], when the solute evaporates, or with changing chemical conditions in the [pb_glossary id=\"1783\"]solution[\/pb_glossary]. An example of [pb_glossary id=\"1785\"]precipitation[\/pb_glossary] in our homes is when water evaporates and leaves behind a rind of [pb_glossary id=\"1765\"]minerals[\/pb_glossary] on faucets, shower heads, and drinking glasses.\n\nIn nature, changes in environmental conditions may cause the [pb_glossary id=\"1765\"]minerals[\/pb_glossary] [pb_glossary id=\"1893\"]dissolved[\/pb_glossary] in water to form [pb_glossary id=\"1781\"]bonds[\/pb_glossary] and grow into crystals or cement grains of [pb_glossary id=\"1756\"]sediment[\/pb_glossary] together. In Utah, deposits of [pb_glossary id=\"1924\"]tufa[\/pb_glossary] formed from [pb_glossary id=\"1765\"]mineral[\/pb_glossary]-rich springs that emerged into the [pb_glossary id=\"747\"]ice age[\/pb_glossary] Lake Bonneville. Now exposed in dry valleys, this porous [pb_glossary id=\"1924\"]tufa[\/pb_glossary] was a natural insulation used by pioneers to build their homes with a natural protection against summer heat and winter cold. The [pb_glossary id=\"1925\"]travertine[\/pb_glossary] [pb_glossary id=\"2240\"]terraces[\/pb_glossary] at Mammoth Hot Springs in Yellowstone Park are another example formed by [pb_glossary id=\"970\"]calcite[\/pb_glossary] [pb_glossary id=\"1785\"]precipitation[\/pb_glossary] at the edges of the shallow [pb_glossary id=\"2252\"]spring[\/pb_glossary]-fed ponds.\n\n[caption id=\"attachment_2762\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.6_1200px-Bonneville_Salt_Flats.jpg\"><img class=\"size-medium wp-image-2762\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.6_1200px-Bonneville_Salt_Flats-300x197-1.jpg\" alt=\"The Bonneville Salt Flats of Utah\" width=\"300\" height=\"197\"><\/a> The Bonneville Salt Flats of Utah[\/caption]\n\n<span style=\"font-weight: 400\">Another example of [pb_glossary id=\"1785\"]precipitation[\/pb_glossary] occurs in the Great Salt Lake, Utah, where the concentration of sodium chloride and other salts is nearly eight times greater than in the world\u2019s oceans <\/span><span style=\"font-weight: 400\">[zotpressInText item=\"{DU5CMSHJ}\" format=\"%num%\" brackets=\"yes\"]<\/span><span style=\"font-weight: 400\">.\u00a0<\/span>[pb_glossary id=\"2212\"]Streams[\/pb_glossary] carry salt ions into the lake from the surrounding mountains. With no other outlet, the water in the lake evaporates and the concentration of salt increases until [pb_glossary id=\"1784\"]saturation[\/pb_glossary] is reached and the [pb_glossary id=\"1765\"]minerals[\/pb_glossary] [pb_glossary id=\"1785\"]precipitate[\/pb_glossary] out as [pb_glossary id=\"1756\"]sediments[\/pb_glossary]. Similar salt deposits include [pb_glossary id=\"1922\"]halite[\/pb_glossary] and other precipitates, and occur in other lakes like Mono Lake in California and the Dead Sea.\n<h3><b>3.2.2 Crystallization from Magma<\/b><\/h3>\n[caption id=\"attachment_2763\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.5a_Pahoehoe_toe.jpg\"><img class=\"size-medium wp-image-2763\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.5a_Pahoehoe_toe-300x188-1.jpg\" alt=\"A lava flow\" width=\"300\" height=\"188\"><\/a> Lava, magma at the earth\u2019s surface[\/caption]\n\n&nbsp;\n\nHeat is energy that causes atoms in substances to vibrate. [pb_glossary id=\"1767\"]Temperature[\/pb_glossary] is a measure of the intensity of the vibration. If the vibrations are violent enough, chemical [pb_glossary id=\"1781\"]bonds[\/pb_glossary] are broken and the crystals melt releasing the ions into the melt. [pb_glossary id=\"1750\"]Magma[\/pb_glossary] is molten rock with freely moving ions. When [pb_glossary id=\"1750\"]magma[\/pb_glossary] is emplaced at depth or extruded onto the surface (then called [pb_glossary id=\"1751\"]lava[\/pb_glossary]), it starts to cool and [pb_glossary id=\"1765\"]mineral[\/pb_glossary] crystals can form.\n<h3><b>3.2.3 Precipitation by Organisms<\/b><\/h3>\n[caption id=\"attachment_2764\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.8_Ammonite_Asteroceras.jpg\"><img class=\"size-full wp-image-2764\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.8_Ammonite_Asteroceras.jpg\" alt=\"Shell of an ammonite, an extinct cephalopod, with a spiral shell in a plane.\" width=\"300\" height=\"225\"><\/a> Ammonite shell made of calcium carbonate[\/caption]\n\n<span style=\"font-size: 1em\">Many organisms build bones, shells, and body coverings by extracting ions from water and precipitating [pb_glossary id=\"1765\"]minerals[\/pb_glossary] biologically. The most common [pb_glossary id=\"1765\"]mineral[\/pb_glossary] [pb_glossary id=\"1785\"]precipitated[\/pb_glossary] by organisms is [pb_glossary id=\"970\"]calcite[\/pb_glossary], or calcium [pb_glossary id=\"969\"]carbonate[\/pb_glossary] (CaCO3). [pb_glossary id=\"970\"]Calcite[\/pb_glossary] is often [pb_glossary id=\"1785\"]precipitated[\/pb_glossary] by organisms as a [pb_glossary id=\"2440\"]polymorph[\/pb_glossary] called aragonite. <\/span><strong style=\"font-size: 1em\">[pb_glossary id=\"2440\"]Polymorphs[\/pb_glossary]<\/strong><span style=\"font-size: 1em\"> are crystals with the same chemical formula but different crystal structures. [pb_glossary id=\"1961\"]Marine[\/pb_glossary] invertebrates such as corals and clams [pb_glossary id=\"1785\"]precipitate[\/pb_glossary] aragonite or [pb_glossary id=\"970\"]calcite[\/pb_glossary] for their shells and structures. Upon death, their hard parts accumulate on the [pb_glossary id=\"1963\"]ocean floor[\/pb_glossary] as [pb_glossary id=\"1756\"]sediments[\/pb_glossary], and eventually may become the [pb_glossary id=\"1761\"]sedimentary rock[\/pb_glossary] [pb_glossary id=\"1929\"]limestone[\/pb_glossary]. Though [pb_glossary id=\"1929\"]limestone[\/pb_glossary] can form inorganically, the vast majority is formed by this biological process. Another example is [pb_glossary id=\"1961\"]marine[\/pb_glossary] organisms called radiolaria, which are zooplankton that [pb_glossary id=\"1785\"]precipitate[\/pb_glossary] silica for their microscopic external shells. When the organisms die, the shells accumulate on the [pb_glossary id=\"1963\"]ocean floor[\/pb_glossary] and can form the [pb_glossary id=\"1761\"]sedimentary rock[\/pb_glossary] [pb_glossary id=\"1927\"]chert[\/pb_glossary]. An example of biologic [pb_glossary id=\"1785\"]precipitation[\/pb_glossary] from the [pb_glossary id=\"1274\"]vertebrate[\/pb_glossary] world is bone, which is [pb_glossary id=\"1909\"]composed[\/pb_glossary] mostly of a type of apatite, a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] in the [pb_glossary id=\"975\"]phosphate[\/pb_glossary] group. The apatite found in bones contains calcium and water in its structure and is called hydroxycarbonate apatite, Ca<\/span><sub>5<\/sub><span style=\"font-size: 1em\">(PO<\/span><sub>4<\/sub><span style=\"font-size: 1em\">)<\/span><sub>3<\/sub><span style=\"font-size: 1em\">(OH).\u00a0 As mentioned above, such substances are not technically [pb_glossary id=\"1765\"]minerals[\/pb_glossary] until the organism dies and these hard parts become [pb_glossary id=\"1228\"]fossils[\/pb_glossary].<\/span>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"18\"]\n\n[caption id=\"attachment_3753\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.2-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-154\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 3.2 via this QR Code.[\/caption]\n<h2><span style=\"font-weight: 400\">3.3 Silicate Minerals<\/span><\/h2>\n[caption id=\"attachment_2765\" align=\"alignright\" width=\"256\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tetrahedron.gif\"><img class=\"size-full wp-image-2765\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tetrahedron.gif\" alt=\"It is a pyramid shape with a triangular base\" width=\"256\" height=\"256\"><\/a> Rotating animation of a tetrahedra[\/caption]\n\n[pb_glossary id=\"1765\"]Minerals[\/pb_glossary] are categorized based on their [pb_glossary id=\"1909\"]composition[\/pb_glossary] and structure. [pb_glossary id=\"1787\"]Silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are built around a molecular [pb_glossary id=\"2449\"]ion[\/pb_glossary] called the <strong>[pb_glossary id=\"1788\"]silicon-oxygen tetrahedron[\/pb_glossary]<\/strong>. A tetrahedron has a pyramid-like shape with four sides and four corners.\u00a0[pb_glossary id=\"1787\"]Silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] form the largest group of [pb_glossary id=\"1765\"]minerals[\/pb_glossary] on Earth, comprising the vast majority of the Earth\u2019s [pb_glossary id=\"1664\"]mantle[\/pb_glossary] and [pb_glossary id=\"1658\"]crust[\/pb_glossary]. Of the nearly four thousand known [pb_glossary id=\"1765\"]minerals[\/pb_glossary] on Earth, most are rare. There are only a few that make up most of the rocks likely to be encountered by surface dwelling creatures like us. These are generally called the <strong>rock-forming [pb_glossary id=\"1765\"]minerals[\/pb_glossary]<\/strong>.\n\n[caption id=\"attachment_2766\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.10_Tetrahedron.jpg\"><img class=\"size-medium wp-image-2766\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.10_Tetrahedron-300x300-1.jpg\" alt=\"Model of silicon-oxygen tetrahedron of ping pong balls with a tiny silicon ion in the space in the middle of the four large balls\" width=\"300\" height=\"300\"><\/a> Ping pong ball model of tetrahedron: balls are oxygen, lead sinker in center is silicon[\/caption]\n\nThe [pb_glossary id=\"1788\"]silicon-oxygen tetrahedron[\/pb_glossary] (SiO<sub>4<\/sub>) consists of a single silicon atom at the center and four oxygen atoms located at the four corners of the tetrahedron. Each oxygen [pb_glossary id=\"2449\"]ion[\/pb_glossary] has a -2 charge and the silicon [pb_glossary id=\"2449\"]ion[\/pb_glossary] has a +4 charge. The silicon [pb_glossary id=\"2449\"]ion[\/pb_glossary] shares one of its four valence electrons with each of the four oxygen ions in a covalent [pb_glossary id=\"1781\"]bond[\/pb_glossary] to create a symmetrical geometric four-sided pyramid figure. Only half of the oxygen\u2019s valence electrons are shared, giving the [pb_glossary id=\"1788\"]silicon-oxygen tetrahedron[\/pb_glossary] an ionic charge of -4. This [pb_glossary id=\"1788\"]silicon-oxygen tetrahedron[\/pb_glossary] forms bonds with many other combinations of ions to form the large group of [pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary].\n\n[caption id=\"attachment_2767\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.11_Tetrahedron_open.jpg\"><img class=\"size-medium wp-image-2767\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.11_Tetrahedron_open-300x255-1.jpg\" alt=\"Top ball removed showing the tiny silicon ion in the center\" width=\"300\" height=\"255\"><\/a> The silicon ion in the center of the tetrahedron[\/caption]\n\n<span style=\"font-weight: 400\">The silicon [pb_glossary id=\"2449\"]ion[\/pb_glossary] is much smaller than the oxygen ions (see the figures) and fits into a small space in the center of the four large oxygen ions, seen if the top ball is removed (as shown in the figure to the right). <\/span><span style=\"font-weight: 400\">Because only one of the valence electrons of the corner oxygens is shared, the [pb_glossary id=\"1788\"]silicon-oxygen tetrahedron[\/pb_glossary] has chemically active corners available to form [pb_glossary id=\"1781\"]bonds[\/pb_glossary] with other [pb_glossary id=\"1788\"]silica tetrahedra[\/pb_glossary] or other positively charged ions such as Al<\/span><sub><span style=\"font-weight: 400\">+3<\/span><\/sub><span style=\"font-weight: 400\">, Fe<\/span><sub><span style=\"font-weight: 400\">+2,+3<\/span><\/sub><span style=\"font-weight: 400\">, Mg<\/span><sub><span style=\"font-weight: 400\">+2<\/span><\/sub><span style=\"font-weight: 400\">, K<\/span><sub><span style=\"font-weight: 400\">+1<\/span><\/sub><span style=\"font-weight: 400\">, Na<\/span><sub><span style=\"font-weight: 400\">+1<\/span><\/sub><span style=\"font-weight: 400\">, and Ca<\/span><sub><span style=\"font-weight: 400\">+2<\/span><\/sub><span style=\"font-weight: 400\">. Depending on many factors, such as the original [pb_glossary id=\"1750\"]magma[\/pb_glossary] chemistry, [pb_glossary id=\"1788\"]silica-oxygen tetrahedra[\/pb_glossary] can combine with other tetrahedra in several different configurations. For example, tetrahedra can be isolated, attached in chains, sheets, or three dimensional structures. These combinations and others create the chemical structure in which positively charged ions can be inserted for unique chemical compositions forming [pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary] groups. \u00a0\u00a0<\/span>\n<h3><b>3.3.1 The dark ferromagnesian silicates<\/b><\/h3>\n&nbsp;\n\n[caption id=\"attachment_2768\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.12_Peridot_in_basalt.jpg\"><img class=\"size-medium wp-image-2768\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.12_Peridot_in_basalt-300x225-1.jpg\" alt=\"Many small crystall of the green mineral olivine in a mass of basalt\" width=\"300\" height=\"225\"><\/a> Olivine crystals in basalt[\/caption]\n\n<span style=\"font-size: 14pt\"><b>The [pb_glossary id=\"1789\"]Olivine[\/pb_glossary] Family<\/b><\/span>\n\n[pb_glossary id=\"1789\"]Olivine[\/pb_glossary] is the primary [pb_glossary id=\"1765\"]mineral[\/pb_glossary] component in [pb_glossary id=\"1664\"]mantle[\/pb_glossary] rock such as [pb_glossary id=\"1666\"]peridotite[\/pb_glossary] and [pb_glossary id=\"1013\"]basalt[\/pb_glossary]. It is characteristically green when not weathered. The chemical formula is (Fe,Mg)<sub>2<\/sub>SiO<sub>4<\/sub>. As previously described, the comma between iron (Fe) and magnesium (Mg) indicates these two [pb_glossary id=\"1778\"]elements[\/pb_glossary] occur in a [pb_glossary id=\"1786\"]solid solution[\/pb_glossary].\u00a0<span style=\"font-weight: 400\">Not to be confused with a liquid [pb_glossary id=\"1783\"]solution[\/pb_glossary], a [pb_glossary id=\"1786\"]solid solution[\/pb_glossary] occurs when two or more [pb_glossary id=\"1778\"]elements[\/pb_glossary] have similar properties and can freely substitute for each other in the same location in the crystal structure.<\/span>\n\n[caption id=\"attachment_2769\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.13_Atomic_structure_of_olivine_1.png\"><img class=\"size-full wp-image-2769\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.13_Atomic_structure_of_olivine_1.png\" alt=\"Tetrahedral structure of olivine showing the independent tetrahedra connected together by anions of iron and\/or magnesium.\" width=\"300\" height=\"258\"><\/a> Tetrahedral structure of olivine[\/caption]\n\n<span style=\"font-weight: 400\">[pb_glossary id=\"1789\"]Olivine[\/pb_glossary] is referred to as a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] family because of the ability of iron and magnesium to substitute for each other. Iron and magnesium in the [pb_glossary id=\"1789\"]olivine[\/pb_glossary] family indicates a [pb_glossary id=\"1786\"]solid solution[\/pb_glossary] forming a compositional series within the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] group which can form crystals of all iron as one end member and all mixtures of iron and magnesium in between to all magnesium at the other end member. Different [pb_glossary id=\"1765\"]mineral[\/pb_glossary] names are applied to compositions between these end members.\u00a0 In the [pb_glossary id=\"1789\"]olivine[\/pb_glossary] series of [pb_glossary id=\"1765\"]minerals[\/pb_glossary], the iron and magnesium ions in the [pb_glossary id=\"1786\"]solid solution[\/pb_glossary] are about the same size and charge, so either atom can fit into the same location in the growing crystals. Within the cooling [pb_glossary id=\"1750\"]magma[\/pb_glossary], the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] crystals continue to grow until they solidify into [pb_glossary id=\"1753\"]igneous rock[\/pb_glossary]. The relative amounts of iron and magnesium in the parent [pb_glossary id=\"1750\"]magma[\/pb_glossary] determine which [pb_glossary id=\"1765\"]minerals[\/pb_glossary] in the series form. Other rarer [pb_glossary id=\"1778\"]elements[\/pb_glossary] with similar properties to iron or magnesium, like manganese (Mn), can substitute into the [pb_glossary id=\"1789\"]olivine[\/pb_glossary] crystalline structure in small amounts. Such ionic substitutions in [pb_glossary id=\"1765\"]mineral[\/pb_glossary] crystals give rise to the great variety of [pb_glossary id=\"1765\"]minerals[\/pb_glossary] and are often responsible for differences in color and other properties within a group or family of [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. [pb_glossary id=\"1789\"]Olivine[\/pb_glossary] has a pure iron end-member (called fayalite) and a pure magnesium end-member (called forsterite). Chemically, [pb_glossary id=\"1789\"]olivine[\/pb_glossary] is mostly silica, iron, and magnesium and therefore is grouped among the dark-colored <\/span>ferromagnesian<span style=\"font-weight: 400\"> (iron=ferro, magnesium=magnesian) or <strong>[pb_glossary id=\"1008\"]mafic[\/pb_glossary]<\/strong> [pb_glossary id=\"1765\"]minerals[\/pb_glossary], a contraction of their chemical symbols Ma and Fe. [pb_glossary id=\"1008\"]Mafic[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are also referred to as dark-colored ferromagnesian [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. <em>Ferro<\/em> means iron and <em>magnesian<\/em> refers to magnesium. Ferromagnesian [pb_glossary id=\"1787\"]silicates[\/pb_glossary] tend to be more dense than non-ferromagnesian [pb_glossary id=\"1787\"]silicates[\/pb_glossary]. This difference in density ends up being important in controlling the behavior of the [pb_glossary id=\"1753\"]igneous[\/pb_glossary] rocks that are built from these [pb_glossary id=\"1765\"]minerals[\/pb_glossary]: whether a [pb_glossary id=\"1654\"]tectonic[\/pb_glossary] [pb_glossary id=\"1669\"]plate[\/pb_glossary] [pb_glossary id=\"1680\"]subducts[\/pb_glossary] or not is largely governed by the density of its rocks, which are in turn controlled by the density of the [pb_glossary id=\"1765\"]minerals[\/pb_glossary] that comprise them.<\/span>\n\nThe crystal structure of [pb_glossary id=\"1789\"]olivine[\/pb_glossary] is built from independent [pb_glossary id=\"1788\"]silica tetrahedra[\/pb_glossary]. [pb_glossary id=\"1765\"]Minerals [\/pb_glossary]with independent tetrahedral structures are called neosilicates (or orthosilicates). In addition to [pb_glossary id=\"1789\"]olivine[\/pb_glossary], other common neosilicate [pb_glossary id=\"1765\"]minerals[\/pb_glossary] include garnet, topaz, kyanite, and [pb_glossary id=\"1227\"]zircon[\/pb_glossary].\n\nTwo other similar arrangements of tetrahedra are close in structure to the neosilicates and [pb_glossary id=\"2016\"]grade[\/pb_glossary] toward the next group of [pb_glossary id=\"1765\"]minerals[\/pb_glossary], the pyroxenes. In a variation on independent tetrahedra called sorosilicates, there are [pb_glossary id=\"1765\"]minerals[\/pb_glossary] that share one oxygen between two tetrahedra, and include [pb_glossary id=\"1765\"]minerals[\/pb_glossary] like pistachio-green epidote, a gemstone. Another variation are the cyclosilicates, which as the name suggests, consist of tetrahedral rings, and include gemstones such as beryl, emerald, aquamarine, and tourmaline\n<h3><b>3.3.2 Pyroxene Family<\/b><\/h3>\n&nbsp;\n\n[caption id=\"attachment_2770\" align=\"aligncenter\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.14_Diopside-172005.jpg\"><img class=\"wp-image-2770 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.14_Diopside-172005-300x231-1.jpg\" alt=\"Dark green crystals of diopside, a member of the pyroxene family\" width=\"300\" height=\"231\"><\/a> Crystals of diopside, a member of the pyroxene family[\/caption]\n\n&nbsp;\n\n[caption id=\"attachment_2771\" align=\"alignright\" width=\"70\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.15_Pyroxen-chain.png\"><img class=\"wp-image-2771\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.15_Pyroxen-chain.png\" alt=\"Single chain of tetrahedra in pyroxene, alternating with adjacent corner oxygens bonded. The outer corners are active to bond with other anions.\" width=\"70\" height=\"517\"><\/a> Single chain tetrahedral structure in pyroxene[\/caption]\n\n[pb_glossary id=\"1790\"]Pyroxene[\/pb_glossary] is another family of dark ferromagnesian [pb_glossary id=\"1765\"]minerals[\/pb_glossary], typically black or dark green in color. Members of the [pb_glossary id=\"1790\"]pyroxene[\/pb_glossary] family have a complex chemical [pb_glossary id=\"1909\"]composition[\/pb_glossary] that includes iron, magnesium, aluminum, and other [pb_glossary id=\"1778\"]elements[\/pb_glossary] [pb_glossary id=\"1781\"]bonded[\/pb_glossary] to polymerized [pb_glossary id=\"1788\"]silica tetrahedra[\/pb_glossary]. <strong>Polymers<\/strong> are chains, sheets, or three-dimensional structures, and are formed by multiple tetrahedra covalently [pb_glossary id=\"1781\"]bonded[\/pb_glossary] via their corner oxygen atoms. Pyroxenes are commonly found in [pb_glossary id=\"1008\"]mafic[\/pb_glossary] [pb_glossary id=\"1753\"]igneous[\/pb_glossary] rocks such as [pb_glossary id=\"1666\"]peridotite[\/pb_glossary], [pb_glossary id=\"1013\"]basalt[\/pb_glossary], and [pb_glossary id=\"1016\"]gabbro[\/pb_glossary], as well as [pb_glossary id=\"1992\"]metamorphic[\/pb_glossary] rocks like eclogite and blue [pb_glossary id=\"2007\"]schist[\/pb_glossary].\n\nPyroxenes are built from long, single chains of polymerized [pb_glossary id=\"1788\"]silica tetrahedra[\/pb_glossary] in which tetrahedra share two corner oxygens. The silica chains are [pb_glossary id=\"1781\"]bonded[\/pb_glossary] together into the crystal structures by metal cations. A common member of the [pb_glossary id=\"1790\"]pyroxene[\/pb_glossary] family is augite, itself containing several [pb_glossary id=\"1786\"]solid solution[\/pb_glossary] series with a complex chemical formula (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)<sub>2<\/sub>O<sub>6<\/sub> that gives rise to a number of individual [pb_glossary id=\"1765\"]mineral[\/pb_glossary] names.\n\nThis single-chain crystalline structure [pb_glossary id=\"1781\"]bonds[\/pb_glossary] with many [pb_glossary id=\"1778\"]elements[\/pb_glossary], which can also freely substitute for each other. The generalized chemical [pb_glossary id=\"1909\"]composition[\/pb_glossary] for [pb_glossary id=\"1790\"]pyroxene[\/pb_glossary] is XZ(Al,Si)<sub>2<\/sub>O<sub>6<\/sub>. X represents the ions Na, Ca, Mg, or Fe, and Z represents Mg, Fe, or Al. These ions have similar ionic sizes, which allows many possible substitutions among them. Although the [pb_glossary id=\"1780\"]cations[\/pb_glossary] may freely substitute for each other in the crystal, they carry different ionic charges that must be balanced out in the final crystalline structure. For example Na has a charge of +1, but Ca has charge of +2. If a Na<sup>+<\/sup> [pb_glossary id=\"2449\"]ion[\/pb_glossary] substitutes for a Ca<sup>+2<\/sup> [pb_glossary id=\"2449\"]ion[\/pb_glossary], it creates an unequal charge that must be balanced by other ionic substitutions elsewhere in the crystal. Note that ionic size is more important than ionic charge for substitutions to occur in [pb_glossary id=\"1786\"]solid solution[\/pb_glossary] series in crystals.\n<h3><\/h3>\n<h3><b>3.3.3 Amphibole Family<\/b><\/h3>\n[caption id=\"attachment_2773\" align=\"alignleft\" width=\"200\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.15_Orthoclase_Hornblende.jpg\"><img class=\"wp-image-2773\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.15_Orthoclase_Hornblende-300x300-1.jpg\" alt=\"A crystal of orthoclase (potassium feldspar) wth elongated dark crystals of hornblende\" width=\"200\" height=\"200\"><\/a> Elongated crystals of hornblende in orthoclase[\/caption]\n\n&nbsp;\n\n[caption id=\"attachment_2772\" align=\"alignright\" width=\"200\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.16_Amphibole.jpg\"><img class=\"wp-image-2772\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.16_Amphibole-300x236-1.jpg\" alt=\"Black crystals of hornblende\" width=\"200\" height=\"157\"><\/a> Hornblende crystals[\/caption]\n\n[pb_glossary id=\"1791\"]Amphibole[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are built from polymerized double silica chains and they are also referred to as inosilicates. Imagine two [pb_glossary id=\"1790\"]pyroxene[\/pb_glossary] chains that connect together by sharing a third oxygen on each tetrahedra.\u00a0 Amphiboles are usually found in [pb_glossary id=\"1753\"]igneous[\/pb_glossary] and [pb_glossary id=\"1992\"]metamorphic[\/pb_glossary] rocks and typically have a long-bladed <strong>[pb_glossary id=\"980\"]crystal habit[\/pb_glossary]<\/strong>. The most common [pb_glossary id=\"1791\"]amphibole[\/pb_glossary], hornblende, is usually black; however, they come in a variety of colors depending on their chemical [pb_glossary id=\"1909\"]composition[\/pb_glossary]. The [pb_glossary id=\"1762\"]metamorphic rock[\/pb_glossary], amphibolite, is primarily [pb_glossary id=\"1909\"]composed[\/pb_glossary] of [pb_glossary id=\"1791\"]amphibole[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary].\n\n[caption id=\"attachment_2774\" align=\"alignleft\" width=\"79\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.17_Tremolite-chain.png\"><img class=\"size-medium wp-image-2774\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.17_Tremolite-chain-79x300-1.png\" alt=\"Double chain structure of amphibole; two single chains laying together with the inner corners of each tetrahedron bonded and the outer cornera active to bond with anions\" width=\"79\" height=\"300\"><\/a> Double chain structure[\/caption]\n\n&nbsp;\n\nAmphiboles are [pb_glossary id=\"1909\"]composed[\/pb_glossary] of iron, magnesium, aluminum, and other [pb_glossary id=\"1780\"]cations[\/pb_glossary] [pb_glossary id=\"1781\"]bonded[\/pb_glossary] with [pb_glossary id=\"1788\"]silica tetrahedra[\/pb_glossary]. These dark ferromagnesian [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are commonly found in [pb_glossary id=\"1016\"]gabbro[\/pb_glossary], baslt, [pb_glossary id=\"1015\"]diorite[\/pb_glossary], and often form the black specks in [pb_glossary id=\"1014\"]granite[\/pb_glossary]. Their chemical formula is very complex and generally written as (RSi<sub>4<\/sub>O<sub>11<\/sub>)<sub>2<\/sub>, where R represents many different [pb_glossary id=\"1780\"]cations[\/pb_glossary]. For example, it can also be written more exactly as AX<sub>2<\/sub>Z<sub>5<\/sub>((Si,Al,Ti)<sub>8<\/sub>O<sub>22<\/sub>)(OH,F,Cl,O)<sub>2<\/sub>. In this formula A may be Ca, Na, K, Pb, or blank; X equals Li, Na, Mg, Fe, Mn, or Ca; and Z is Li, Na, Mg, Fe, Mn, Zn, Co, Ni, Al, \u00a0Cr, Mn, V, Ti, or Zr. The substitutions create a wide variety of colors such as green, black, colorless, white, yellow, blue, or brown. [pb_glossary id=\"1791\"]Amphibole[\/pb_glossary] crystals can also include hydroxide ions (OH<sup>-<\/sup>)<sup>,<\/sup> which occurs from an interaction between the growing [pb_glossary id=\"1765\"]minerals[\/pb_glossary] and water [pb_glossary id=\"1893\"]dissolved[\/pb_glossary] in [pb_glossary id=\"1750\"]magma[\/pb_glossary].\n<h3><\/h3>\n<h3><\/h3>\n<h3><strong>3.3.4 Sheet Silicates<\/strong><\/h3>\n[caption id=\"attachment_2775\" align=\"alignleft\" width=\"200\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.19_Biotite_aggregate_-_Ochtendung_Eifel_Germany.jpg\"><img class=\"wp-image-2775\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.19_Biotite_aggregate_-_Ochtendung_Eifel_Germany-300x225-1.jpg\" alt=\"Dark brown crystals of biotite mica showing sheet-like habit\" width=\"200\" height=\"150\"><\/a> Sheet crystals of biotite mica[\/caption]\n\n[caption id=\"attachment_3637\" align=\"alignright\" width=\"250\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MicaSheetUSGOV.jpg\"><img class=\"wp-image-166\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MicaSheetUSGOV-300x226.jpg\" alt=\"Crystal of muscovite mica showing sheet structure of the mineral\" width=\"250\" height=\"188\"><\/a> Crystal of muscovite mica[\/caption]\n\nSheet [pb_glossary id=\"1787\"]silicates[\/pb_glossary] are built from tetrahedra which share all three of their bottom corner oxygens thus forming sheets of tetrahedra with their top corners available for [pb_glossary id=\"1781\"]bonding[\/pb_glossary] with other atoms. Micas and clays are common types of sheet [pb_glossary id=\"1787\"]silicates[\/pb_glossary], also known as phyllosilicates. [pb_glossary id=\"966\"]Mica[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are usually found in [pb_glossary id=\"1753\"]igneous[\/pb_glossary] and [pb_glossary id=\"1992\"]metamorphic[\/pb_glossary] rocks, while clay [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are more often found in sedimentary rocks. Two frequently found micas are dark-colored [pb_glossary id=\"966\"]biotite[\/pb_glossary], frequently found in [pb_glossary id=\"1014\"]granite[\/pb_glossary], and light-colored [pb_glossary id=\"966\"]muscovite[\/pb_glossary], found in the [pb_glossary id=\"1762\"]metamorphic rock[\/pb_glossary] called [pb_glossary id=\"2007\"]schist[\/pb_glossary].\n\n[caption id=\"attachment_2777\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.20_Silicate-sheet-3D-polyhedra.png\"><img class=\"size-medium wp-image-2777\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.20_Silicate-sheet-3D-polyhedra-300x197-1.png\" alt=\"Continuous sheets of tetradedra with all three base corners bonded to each other; the top corner active to bond with anions\" width=\"300\" height=\"197\"><\/a> Sheet structure of mica[\/caption]\n\nChemically, sheet [pb_glossary id=\"1787\"]silicates[\/pb_glossary] usually contain silicon and oxygen in a 2:5 ratio (Si<sub>4<\/sub>O<sub>10<\/sub>). Micas contain mostly silica, aluminum, and potassium. [pb_glossary id=\"966\"]Biotite[\/pb_glossary] [pb_glossary id=\"966\"]mica[\/pb_glossary] has more iron and magnesium and is considered a ferromagnesian [pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary]. [pb_glossary id=\"966\"]Muscovite[\/pb_glossary] micas belong to the [pb_glossary id=\"1006\"]felsic[\/pb_glossary] [pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. [pb_glossary id=\"1006\"]Felsic[\/pb_glossary] is a contraction formed from [pb_glossary id=\"968\"]feldspar[\/pb_glossary], the dominant [pb_glossary id=\"1765\"]mineral[\/pb_glossary] in [pb_glossary id=\"1006\"]felsic[\/pb_glossary] rocks.\n\n[caption id=\"attachment_2778\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.21_Crystal-structure-of-mica.jpg\"><img class=\"size-medium wp-image-2778\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.21_Crystal-structure-of-mica-300x300-1.jpg\" alt=\"Diagram of mica crystal structure with the sheets of tetrahedra inverted onto each other into sandwiches with the active corners bonded with anions and the sandwiches connected together with large potassium ions that form weak bonds easily separated so the crystal comes apart into sheets.\" width=\"300\" height=\"300\"><\/a> Crystal structure of a mica[\/caption]\n\n[caption id=\"attachment_2779\" align=\"alignright\" width=\"296\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Illmenite-mica-sandwich.jpg\"><img class=\"size-medium wp-image-2779\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Illmenite-mica-sandwich-296x300-1.jpg\" alt=\"Silica sheets layered in mica like bread and hjam in a stack of sandwiches\" width=\"296\" height=\"300\"><\/a> Mica \"silica sandwich\" structure[\/caption]\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\nThe illustration of the crystalline structure of [pb_glossary id=\"966\"]mica[\/pb_glossary] shows the corner O atoms [pb_glossary id=\"1781\"]bonded[\/pb_glossary] with K, Al, Mg, Fe, and Si atoms, forming polymerized sheets of linked tetrahedra, with an octahedral layer of Fe, Mg, or Al, between them.\u00a0 The yellow potassium ions form Van der Waals [pb_glossary id=\"1781\"]bonds[\/pb_glossary] (attraction and repulsion between atoms, molecules, and surfaces) and hold the sheets together. Van der Waals [pb_glossary id=\"1781\"]bonds[\/pb_glossary] differ from\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Covalent_bond\">covalent<\/a>\u00a0and\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Ionic_bond\">ionic<\/a>\u00a0[pb_glossary id=\"1781\"]bonds[\/pb_glossary], and exist here between the sandwiches, holding them together into a [pb_glossary id=\"2291\"]stack[\/pb_glossary] of sandwiches. The Van der Waals [pb_glossary id=\"1781\"]bonds[\/pb_glossary] are weak compared to the [pb_glossary id=\"1781\"]bonds[\/pb_glossary] within the sheets, allowing the sandwiches to be separated along the potassium layers. This gives [pb_glossary id=\"966\"]mica[\/pb_glossary] its characteristic property of easily cleaving into sheets.\n\n[caption id=\"attachment_2780\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.22_Kaolinite-structure.jpg\"><img class=\"size-medium wp-image-2780\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.22_Kaolinite-structure-300x244-1.jpg\" alt=\"Crystal structure of kaolinite, a clay mineral with sheet structure like mica except that the\" width=\"300\" height=\"244\"><\/a> Structure of kaolinite[\/caption]\n\nClays [pb_glossary id=\"1765\"]minerals[\/pb_glossary] occur in [pb_glossary id=\"1756\"]sediments[\/pb_glossary] formed by the [pb_glossary id=\"1754\"]weathering[\/pb_glossary] of rocks and are another family of [pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] with a tetrahedral sheet structure. Clay [pb_glossary id=\"1765\"]minerals[\/pb_glossary] form a complex family, and are an important component of many sedimentary rocks. Other sheet [pb_glossary id=\"1787\"]silicates[\/pb_glossary] include serpentine and chlorite, found in [pb_glossary id=\"1992\"]metamorphic[\/pb_glossary] rocks.\n\nClay [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are [pb_glossary id=\"1909\"]composed[\/pb_glossary] of hydrous aluminum [pb_glossary id=\"1787\"]silicates[\/pb_glossary]. One type of clay, kaolinite, has a structure like an open-faced sandwich, with the bread being a single layer of [pb_glossary id=\"1788\"]silicon-oxygen tetrahedra[\/pb_glossary] and a layer of aluminum as the spread in an octahedral configuration with the top oxygens of the sheets.\n<h3><b>3.3.5 Framework Silicates<\/b><\/h3>\n[caption id=\"attachment_2829\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Quartz-crystals.jpg\"><img class=\"size-medium wp-image-2829\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Quartz-crystals-300x284-1.jpg\" alt=\"Freely grown quartz crystals showing crysatl faces\" width=\"300\" height=\"284\"><\/a> Freely growing quartz crystals showing crystal faces[\/caption]\n\n&nbsp;\n\n[pb_glossary id=\"967\"]Quartz[\/pb_glossary] and [pb_glossary id=\"968\"]feldspar[\/pb_glossary] are the two most abundant [pb_glossary id=\"1765\"]minerals[\/pb_glossary] in the [pb_glossary id=\"1653\"]continental crust[\/pb_glossary]. In fact, [pb_glossary id=\"968\"]feldspar[\/pb_glossary] itself is the single most abundant [pb_glossary id=\"1765\"]mineral[\/pb_glossary] in the Earth\u2019s [pb_glossary id=\"1658\"]crust[\/pb_glossary]. There are two types of [pb_glossary id=\"968\"]feldspar[\/pb_glossary], one containing potassium and abundant in [pb_glossary id=\"1006\"]felsic[\/pb_glossary] rocks of the [pb_glossary id=\"1653\"]continental crust[\/pb_glossary], and the other with sodium and calcium abundant in the [pb_glossary id=\"1008\"]mafic[\/pb_glossary] rocks of [pb_glossary id=\"1659\"]oceanic crust[\/pb_glossary].\u00a0 Together with [pb_glossary id=\"967\"]quartz[\/pb_glossary], these [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are classified as framework [pb_glossary id=\"1787\"]silicates[\/pb_glossary]. They are built with a three-dimensional framework of [pb_glossary id=\"1788\"]silica tetrahedra[\/pb_glossary] in which all four corner oxygens are shared with adjacent tetrahedra. Within these frameworks in [pb_glossary id=\"968\"]feldspar[\/pb_glossary] are holes and spaces into which other ions like aluminum, potassium, sodium, and calcium can fit giving rise to a variety of [pb_glossary id=\"1765\"]mineral[\/pb_glossary] compositions and [pb_glossary id=\"1765\"]mineral[\/pb_glossary] names.\n\n[caption id=\"attachment_2781\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/min-crust-pie-chart.jpg\"><img class=\"size-medium wp-image-2781\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/min-crust-pie-chart-300x290-1.jpg\" alt=\"Feldspar is 51% of the chart.\" width=\"300\" height=\"290\"><\/a> Mineral abundance pie chart in Earth's crust by Callan Bentley.[\/caption]\n\n[pb_glossary id=\"968\"]Feldspars[\/pb_glossary] are usually found in [pb_glossary id=\"1753\"]igneous[\/pb_glossary] rocks, such as [pb_glossary id=\"1014\"]granite[\/pb_glossary], [pb_glossary id=\"1010\"]rhyolite[\/pb_glossary], and [pb_glossary id=\"1013\"]basalt[\/pb_glossary] as well as [pb_glossary id=\"1992\"]metamorphic[\/pb_glossary] rocks and [pb_glossary id=\"2441\"]detrital[\/pb_glossary] sedimentary rocks. [pb_glossary id=\"2441\"]Detrital[\/pb_glossary] sedimentary rocks are [pb_glossary id=\"1909\"]composed[\/pb_glossary] of mechanically weathered rock particles, like sand and gravel. [pb_glossary id=\"967\"]Quartz[\/pb_glossary] is especially abundant in [pb_glossary id=\"2441\"]detrital[\/pb_glossary] sedimentary rocks because it is very resistant to disintegration by [pb_glossary id=\"1754\"]weathering[\/pb_glossary]. While [pb_glossary id=\"967\"]quartz[\/pb_glossary] is the most abundant [pb_glossary id=\"1765\"]mineral[\/pb_glossary] on the Earth's surface, due to its durability, the [pb_glossary id=\"968\"]feldspar[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are the most abundant [pb_glossary id=\"1765\"]minerals[\/pb_glossary] in the Earth's [pb_glossary id=\"1658\"]crust[\/pb_glossary], comprising roughly 50% of the total [pb_glossary id=\"1765\"]minerals[\/pb_glossary] that make up the [pb_glossary id=\"1658\"]crust[\/pb_glossary].\n\n[caption id=\"attachment_2782\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.24_kspar280x210-1.jpg\"><img class=\"size-medium wp-image-2782\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.24_kspar280x210-1-300x200-1.jpg\" alt=\"A group of crystals of pink potassium feldspar\" width=\"300\" height=\"200\"><\/a> Pink orthoclase crystals[\/caption]\n\n&nbsp;\n\n[pb_glossary id=\"967\"]Quartz[\/pb_glossary] is [pb_glossary id=\"1909\"]composed[\/pb_glossary] of pure silica, SiO<sub>2<\/sub>, with the tetrahedra arranged in a three dimensional framework. Impurities consisting of atoms within this framework give rise to many varieties of [pb_glossary id=\"967\"]quartz[\/pb_glossary] among which are gemstones like amethyst, rose [pb_glossary id=\"967\"]quartz[\/pb_glossary], and citrine.\u00a0 [pb_glossary id=\"968\"]Feldspars[\/pb_glossary] are mostly silica with aluminum, potassium, sodium, and calcium. Orthoclase [pb_glossary id=\"968\"]feldspar[\/pb_glossary] (KAlSi<sub>3<\/sub>O<sub>8<\/sub>), also called potassium [pb_glossary id=\"968\"]feldspar[\/pb_glossary] or [pb_glossary id=\"968\"]K-spar[\/pb_glossary], is made of silica, aluminum, and potassium. [pb_glossary id=\"967\"]Quartz[\/pb_glossary] and orthoclase [pb_glossary id=\"968\"]feldspar[\/pb_glossary] are [pb_glossary id=\"1006\"]felsic[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. [pb_glossary id=\"1006\"]Felsic[\/pb_glossary] is the compositional term applied to [pb_glossary id=\"1653\"]continental[\/pb_glossary] [pb_glossary id=\"1753\"]igneous[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] and rocks that contain an abundance of silica. Another [pb_glossary id=\"968\"]feldspar[\/pb_glossary] is [pb_glossary id=\"968\"]plagioclase[\/pb_glossary] with the formula (Ca,Na)AlSi<sub>3<\/sub>O<sub>8<\/sub>, the [pb_glossary id=\"1786\"]solid solution[\/pb_glossary] (Ca,Na) indicating a series of [pb_glossary id=\"1765\"]minerals[\/pb_glossary], one end of the series with calcium CaAl<sub>2<\/sub>Si<sub>2<\/sub>O<sub>8<\/sub>, called anorthite, and the other end with sodium NaAlSi<sub>3<\/sub>O<sub>8<\/sub>, called albite.\u00a0Note how the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] accommodates the substitution of Ca<sup>++<\/sup> and Na<sup>+<\/sup>. [pb_glossary id=\"1765\"]Minerals[\/pb_glossary] in this solid solution series have different [pb_glossary id=\"1765\"]mineral[\/pb_glossary] names.\n\n[caption id=\"attachment_2783\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/23-feldspar-structure.gif\"><img class=\"size-medium wp-image-2783\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/23-feldspar-structure-300x271-1.gif\" alt=\"Framework structure of feldspar with all corners of tetrahedra shared with adjacent tetrahedra; there are holes in the structure in which large anions like potassium and sodium\/calcium fit\" width=\"300\" height=\"271\"><\/a> Crystal structure of feldspar[\/caption]\n\nNote that aluminum, which has a similar ionic size to silicon, can substitute for silicon inside the tetrahedra (see figure). Because potassium ions are so much larger than sodium and calcium ions, which are very similar in size, the inability of the crystal lattice to accommodate both potassium and sodium\/calcium gives rise to the two families of [pb_glossary id=\"968\"]feldspar[\/pb_glossary], orthoclase and [pb_glossary id=\"968\"]plagioclase[\/pb_glossary] respectively.\u00a0Framework [pb_glossary id=\"1787\"]silicates[\/pb_glossary] are called tectosilicates and include the alkali metal-rich feldspathoids and zeolites.\n<h3><\/h3>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"19\"]\n\n[caption id=\"attachment_3752\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.3-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-175\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 3.3 via this QR Code.[\/caption]\n<h2><span style=\"font-weight: 400\">3.4 Non-Silicate Minerals<\/span><\/h2>\n[caption id=\"attachment_2784\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Hanksite.jpg\"><img class=\"size-medium wp-image-2784\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hanksite-300x200-1.jpg\" alt=\"The mineral is hexagonal and clear.\" width=\"300\" height=\"200\"><\/a> Hanksite, Na22K(SO4)9(CO3)2Cl, one of the few minerals that is considered a carbonate and a sulfate[\/caption]\n\n&nbsp;\n\nThe crystal structure of non-[pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] (see table) does not contain [pb_glossary id=\"1788\"]silica-oxygen tetrahedra[\/pb_glossary]. Many non-[pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are economically important and provide [pb_glossary id=\"2423\"]metallic[\/pb_glossary] resources such as copper, lead, and iron. They also include valuable non-[pb_glossary id=\"2423\"]metallic[\/pb_glossary] products such as salt, construction materials, and fertilizer.\n<table>\n<tbody>\n<tr>\n<td><b>[pb_glossary id=\"1765\"]Mineral[\/pb_glossary] \u00a0Group<\/b><\/td>\n<td><b>Examples<\/b><\/td>\n<td><b>Formula<\/b><\/td>\n<td><b>Uses<\/b><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"976\"]Native[\/pb_glossary] [pb_glossary id=\"1778\"]elements[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">gold, silver, copper<\/span><\/td>\n<td><span style=\"font-weight: 400\">Au, Ag, Cu<\/span><\/td>\n<td><span style=\"font-weight: 400\">Jewelry, coins, industry<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"969\"]Carbonates[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"970\"]calcite[\/pb_glossary], dolomite <\/span><\/td>\n<td><span style=\"font-weight: 400\">CaCO<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">, CaMg(CO<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">)<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><\/td>\n<td><span style=\"font-weight: 400\">Lime, Portland cement<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"971\"]Oxides[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">hematite, magnetite, [pb_glossary id=\"2435\"]bauxite[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">Fe<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><span style=\"font-weight: 400\">O<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">, Fe<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">O<\/span><sub><span style=\"font-weight: 400\">4<\/span><\/sub><span style=\"font-weight: 400\">, a mixture of aluminum [pb_glossary id=\"971\"]oxides[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2403\"]Ores[\/pb_glossary] of iron &amp; aluminum, pigments <\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"972\"]Halides[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"1922\"]halite[\/pb_glossary], sylvite<\/span><\/td>\n<td><span style=\"font-weight: 400\">NaCl, KCl<\/span><\/td>\n<td><span style=\"font-weight: 400\">Table salt, fertilizer<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"973\"]Sulfides[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">galena, chalcopyrite, cinnabar<\/span><\/td>\n<td><span style=\"font-weight: 400\">PbS, CuFeS<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><span style=\"font-weight: 400\">, HgS<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"2403\"]Ores[\/pb_glossary] of lead, copper, mercury<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Sulphates<\/span><\/td>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"1921\"]gypsum[\/pb_glossary], epsom salts<\/span><\/td>\n<td><span style=\"font-weight: 400\">CaSo<\/span><sub><span style=\"font-weight: 400\">4<\/span><\/sub><span style=\"font-weight: 400\">\u00b72H<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><span style=\"font-weight: 400\">O, MgSO<\/span><sub><span style=\"font-weight: 400\">4<\/span><\/sub><span style=\"font-weight: 400\">\u00b77H<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><span style=\"font-weight: 400\">O<\/span><\/td>\n<td><span style=\"font-weight: 400\">Sheetrock, therapeutic soak<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">[pb_glossary id=\"975\"]Phosphates[\/pb_glossary]<\/span><\/td>\n<td><span style=\"font-weight: 400\">apatite<\/span><\/td>\n<td><span style=\"font-weight: 400\">Ca<\/span><sub><span style=\"font-weight: 400\">5<\/span><\/sub><span style=\"font-weight: 400\">(PO<\/span><sub><span style=\"font-weight: 400\">4<\/span><\/sub><span style=\"font-weight: 400\">)<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">(F,Cl,OH) <\/span><\/td>\n<td><span style=\"font-weight: 400\">Fertilizer, teeth, bones<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<em><span style=\"font-weight: 400\">Common non-[pb_glossary id=\"1787\"]<em>silicate<\/em>[\/pb_glossary] [pb_glossary id=\"1765\"]<em>mineral<\/em>[\/pb_glossary] groups.<\/span><\/em>\n<h3><b>3.4.1 Carbonates<\/b><\/h3>\n[caption id=\"attachment_2785\" align=\"alignleft\" width=\"245\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.26_Calcite-rhomb.jpg\"><img class=\"size-medium wp-image-2785\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.26_Calcite-rhomb-245x300-1.jpg\" alt=\"Calcite crystal in a shape called a rhomb like a cube squahed over toward one corner\" width=\"245\" height=\"300\"><\/a> Calcite crystal in shape of rhomb. Note the double-refracted word \u201ccalcite\u201d in the center of the figure due to birefringence.[\/caption]\n\n[caption id=\"attachment_2786\" align=\"alignright\" width=\"200\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.29_Limestone_etched_section_KopeFm_new.jpg\"><img class=\"wp-image-2786\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.29_Limestone_etched_section_KopeFm_new-281x300-1.jpg\" alt=\"Piece of limestone rock full of small fossils\" width=\"200\" height=\"214\"><\/a> Limestone with small fossils[\/caption]\n\n[pb_glossary id=\"970\"]Calcite[\/pb_glossary]\u00a0(CaCO<sub>3<\/sub>) and dolomite (CaMg(CO<sub>3<\/sub>)<sub>2<\/sub>) are the two most frequently occurring [pb_glossary id=\"969\"]carbonate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary], and usually occur in sedimentary rocks, such as [pb_glossary id=\"1929\"]limestone[\/pb_glossary] and dolostone rocks, respectively. Some [pb_glossary id=\"969\"]carbonate[\/pb_glossary] rocks, such [pb_glossary id=\"970\"]calcite[\/pb_glossary] and dolomite, are formed via evaporation and [pb_glossary id=\"1785\"]precipitation[\/pb_glossary]. However, most [pb_glossary id=\"969\"]carbonate[\/pb_glossary]-rich rocks, such as [pb_glossary id=\"1929\"]limestone[\/pb_glossary], are created by the [pb_glossary id=\"1760\"]lithification[\/pb_glossary] of fossilized [pb_glossary id=\"1961\"]marine[\/pb_glossary] organisms. These organisms, including those we can see and many microscopic organisms, have shells or exoskeletons consisting of calcium [pb_glossary id=\"969\"]carbonate[\/pb_glossary] (CaCO<sub>3<\/sub>). When these organisms die, their remains accumulate on the floor of the water body in which they live and the soft body parts decompose and [pb_glossary id=\"1893\"]dissolve[\/pb_glossary] away. The calcium [pb_glossary id=\"969\"]carbonate[\/pb_glossary] hard parts become included in the [pb_glossary id=\"1756\"]sediments[\/pb_glossary], eventually becoming the [pb_glossary id=\"1761\"]sedimentary rock[\/pb_glossary] called [pb_glossary id=\"1929\"]limestone[\/pb_glossary]. While [pb_glossary id=\"1929\"]limestone[\/pb_glossary] may contain large, easy to see [pb_glossary id=\"1228\"]fossils[\/pb_glossary], most [pb_glossary id=\"1929\"]limestones[\/pb_glossary] contain the remains of microscopic creatures and thus originate from biological processes.\n\n[caption id=\"attachment_2787\" align=\"alignleft\" width=\"282\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Bifringence.jpg\"><img class=\"size-medium wp-image-2787\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bifringence-282x300-1.jpg\" alt=\"Calcite crystal polarize light into two waves that vibrate at right angles to each other and pass through the crystal in different paths.\" width=\"282\" height=\"300\"><\/a> Bifringence in calcite crystals[\/caption]\n\n[pb_glossary id=\"970\"]Calcite[\/pb_glossary] crystals show an interesting property called <strong>birefringence<\/strong>, meaning they polarize light into two wave components vibrating at right angles to each other. As the two light waves pass through the crystal, they travel at different velocities and are separated by [pb_glossary id=\"2169\"]refraction[\/pb_glossary] into two different travel paths. In other words, the crystal produces a double image of objects viewed through it. Because they polarize light, [pb_glossary id=\"970\"]calcite[\/pb_glossary] crystals are used in special petrographic microscopes for studying [pb_glossary id=\"1765\"]minerals[\/pb_glossary] and rocks.\n\nMany non-[pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are referred to as salts. The term <strong>salts<\/strong> used here refers to compounds made by replacing the hydrogen in natural acids. The most abundant natural acid is [pb_glossary id=\"1891\"]carbonic acid[\/pb_glossary] that forms by the [pb_glossary id=\"1783\"]solution[\/pb_glossary] of carbon dioxide in water. [pb_glossary id=\"969\"]Carbonate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are salts built around the [pb_glossary id=\"969\"]carbonate[\/pb_glossary] [pb_glossary id=\"2449\"]ion[\/pb_glossary] (CO3<sup>-2<\/sup>) where calcium and\/or magnesium replace the hydrogen in [pb_glossary id=\"1891\"]carbonic acid[\/pb_glossary] (H<sub>2<\/sub>CO<sub>3<\/sub>). [pb_glossary id=\"970\"]Calcite[\/pb_glossary] and a closely related [pb_glossary id=\"2440\"]polymorph[\/pb_glossary] aragonite are secreted by organisms to form shells and physical structures like corals. Many such creatures draw both calcium and [pb_glossary id=\"969\"]carbonate[\/pb_glossary] from [pb_glossary id=\"1893\"]dissolved[\/pb_glossary] bicarbonate ions (HCO<sub>3<\/sub><sup>-<\/sup>) in ocean water. As seen in the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] identification section below, [pb_glossary id=\"970\"]calcite[\/pb_glossary] is easily [pb_glossary id=\"1893\"]dissolved[\/pb_glossary] in acid and thus effervesces in dilute hydrochloric acid (HCl). Small dropper bottles of dilute hydrochloric acid are often carried by geologists in the field as well as used in [pb_glossary id=\"1765\"]mineral[\/pb_glossary] identification labs.\n\nOther salts include [pb_glossary id=\"1922\"]halite[\/pb_glossary] (NaCl) in which sodium replaces the hydrogen in hydrochloric acid and [pb_glossary id=\"1921\"]gypsum[\/pb_glossary] (Ca[SO<sub>4<\/sub>] \u2022 2 H<sub>2<\/sub>O) in which calcium replaces the hydrogen in sulfuric acid. Note that some water molecules are also included in the [pb_glossary id=\"1921\"]gypsum[\/pb_glossary] crystal. Salts are often formed by evaporation and are called [pb_glossary id=\"1920\"]evaporite[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary].\n\n[caption id=\"attachment_2788\" align=\"alignleft\" width=\"425\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.30_Crystal_structure_of_Calcite.png\"><img class=\"wp-image-2788\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.30_Crystal_structure_of_Calcite.png\" alt=\"Crystal structure of calcite showing the carbonate units of carbon surrounded by three oxygen ions and bonded to calcium ions.\" width=\"425\" height=\"520\"><\/a> Crystal structure of calcite[\/caption]\n\nThe figure shows the crystal structure of [pb_glossary id=\"970\"]calcite[\/pb_glossary] (CaCO<sub>3<\/sub>). Like silicon, carbon has four valence electrons. The [pb_glossary id=\"969\"]carbonate[\/pb_glossary] unit consists of carbon atoms (tiny white dots) covalently [pb_glossary id=\"1781\"]bonded[\/pb_glossary] to three oxygen atoms (red), one oxygen sharing two valence electrons with the carbon and the other two sharing one valence electron each with the carbon, thus creating triangular units with a charge of -2. The negatively charged [pb_glossary id=\"969\"]carbonate[\/pb_glossary] unit forms an ionic [pb_glossary id=\"1781\"]bond[\/pb_glossary] with the Ca [pb_glossary id=\"2449\"]ion[\/pb_glossary] (blue), which as a charge of +2.\n<h3><\/h3>\n<h3><\/h3>\n<h3><\/h3>\n<h3><\/h3>\n<h3><\/h3>\n<h3><b>3.4.2 Oxides, Halides, and Sulfides<\/b><\/h3>\n[caption id=\"attachment_2789\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.31_Iron_oxide_LimoniteUSGOV.jpg\"><img class=\"size-medium wp-image-2789\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.31_Iron_oxide_LimoniteUSGOV-300x256-1.jpg\" alt=\"Image of limonite, a hydrated oxide of iron\" width=\"300\" height=\"256\"><\/a> Limonite, a hydrated oxide of iron[\/caption]\n\nAfter [pb_glossary id=\"969\"]carbonates[\/pb_glossary], the next most common non-[pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are the [pb_glossary id=\"971\"]oxides[\/pb_glossary], [pb_glossary id=\"972\"]halides[\/pb_glossary], and [pb_glossary id=\"973\"]sulfides[\/pb_glossary].\n\n[pb_glossary id=\"971\"]Oxides[\/pb_glossary] consist of metal ions covalently [pb_glossary id=\"1781\"]bonded[\/pb_glossary] with oxygen. The most familiar [pb_glossary id=\"971\"]oxide[\/pb_glossary] is rust, which is a combination of iron [pb_glossary id=\"971\"]oxides[\/pb_glossary] (Fe<sub>2<\/sub>O<sub>3<\/sub>) and hydrated [pb_glossary id=\"971\"]oxides[\/pb_glossary]. Hydrated [pb_glossary id=\"971\"]oxides[\/pb_glossary] form when iron is exposed to oxygen and water. Iron [pb_glossary id=\"971\"]oxides[\/pb_glossary] are important for producing [pb_glossary id=\"2423\"]metallic[\/pb_glossary] iron. When iron [pb_glossary id=\"971\"]oxide[\/pb_glossary] or [pb_glossary id=\"2403\"]ore[\/pb_glossary] is smelted, it produces carbon dioxide (CO<sub>2<\/sub>) and [pb_glossary id=\"2423\"]metallic[\/pb_glossary] iron.\n\nThe red color in rocks is usually due to the presence of iron [pb_glossary id=\"971\"]oxides[\/pb_glossary]. For example, the red [pb_glossary id=\"1912\"]sandstone[\/pb_glossary] cliffs in Zion National Park and throughout Southern Utah consist of white or colorless grains of [pb_glossary id=\"967\"]quartz[\/pb_glossary] coated with iron [pb_glossary id=\"971\"]oxide[\/pb_glossary] which serve as cementing agents holding the grains together.\n\n[caption id=\"attachment_2790\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.32_Hematite_-_oolitic_with_shale_Iron_Oxide_Clinton_Oneida_County_New_York-e1512421695503.jpg\"><img class=\"wp-image-2790 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.32_Hematite_-_oolitic_with_shale_Iron_Oxide_Clinton_Oneida_County_New_York-e1512421695503-300x269-1.jpg\" alt=\"A red form of hematite called oolitic showing a mass of small round nodules\" width=\"300\" height=\"269\"><\/a> Oolitic hematite[\/caption]\n\nOther iron [pb_glossary id=\"971\"]oxides[\/pb_glossary] include limonite, magnetite, and hematite. Hematite occurs in many different crystal forms. The [pb_glossary id=\"985\"]massive[\/pb_glossary] form shows no external structure. Botryoidal hematite shows large concentric blobs. Specular hematite looks like a mass of shiny [pb_glossary id=\"2423\"]metallic[\/pb_glossary] crystals. Oolitic hematite looks like a mass of dull red fish eggs. These different forms of hematite are [pb_glossary id=\"2018\"]polymorphs[\/pb_glossary] and all have the same formula, Fe<sub>2<\/sub>O<sub>3<\/sub>.\n\nOther common [pb_glossary id=\"971\"]oxide[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] include:\n<ul>\n \t<li>ice (H<sub>2<\/sub>O), an [pb_glossary id=\"971\"]oxide[\/pb_glossary] of hydrogen<\/li>\n \t<li>[pb_glossary id=\"2435\"]bauxite[\/pb_glossary] (Al<sub>2<\/sub>H<sub>2<\/sub>O<sub>4<\/sub>), hydrated [pb_glossary id=\"971\"]oxides[\/pb_glossary] of aluminum, an [pb_glossary id=\"2403\"]ore[\/pb_glossary] for producing [pb_glossary id=\"2423\"]metallic[\/pb_glossary] aluminum<\/li>\n \t<li>corundum (Al<sub>2<\/sub>O<sub>3<\/sub>), which includes ruby and sapphire gemstones.<\/li>\n<\/ul>\n&nbsp;\n\n[caption id=\"attachment_2791\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.34_Halite-249324-1.jpg\"><img class=\"size-medium wp-image-2791\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.34_Halite-249324-1-300x225-1.jpg\" alt=\"Crystals of halite showing cubic crystal habit\" width=\"300\" height=\"225\"><\/a> Halite crystal showing cubic habit[\/caption]\n\nThe <strong>[pb_glossary id=\"972\"]halides[\/pb_glossary]<\/strong> consist of halogens in column VII, usually fluorine or chlorine, ionically [pb_glossary id=\"1781\"]bonded[\/pb_glossary] with sodium or other [pb_glossary id=\"1780\"]cations[\/pb_glossary]. These include [pb_glossary id=\"1922\"]halite[\/pb_glossary] or sodium chloride (NaCl), common table salt; sylvite or potassium chloride (KCl); and fluorite or calcium fluoride (CaF<sub>2<\/sub>).\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n[caption id=\"attachment_2792\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.36_2014-07-05_13_04_30_View_across_the_Bonneville_Salt_Falts_Utah_from_ground_level.jpg\"><img class=\"size-medium wp-image-2792\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.36_2014-07-05_13_04_30_View_across_the_Bonneville_Salt_Falts_Utah_from_ground_level-300x220-1.jpg\" alt=\"Photo of salt crust at the Bonneville Salt Flats in Utah with mountains in the background.\" width=\"300\" height=\"220\"><\/a> Salt crystals at the Bonneville Salt Flats[\/caption]\n\n[caption id=\"attachment_2793\" align=\"alignright\" width=\"244\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.35_FluoriteUV-scaled.jpg\"><img class=\"size-medium wp-image-2793\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.35_FluoriteUV-244x300-1.jpg\" alt=\"Purplish crystals of fluorite. The second image shows the deep blue fluorescence of fluorite under ultraviolet light.\" width=\"244\" height=\"300\"><\/a> Fluorite. B shows fluorescence of fluorite under UV light[\/caption]\n\n[pb_glossary id=\"972\"]Halide[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] usually form from the evaporation of sea water or other isolated bodies of water. A well-known example of [pb_glossary id=\"972\"]halide[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary] deposits created by evaporation is the Bonneville Salt Flats, located west of the Great Salt Lake in Utah (see figure).\n\n&nbsp;\n\nMany important metal [pb_glossary id=\"2403\"]ores[\/pb_glossary] are <b>[pb_glossary id=\"973\"]sulfides[\/pb_glossary], <\/b><span style=\"font-weight: 400\">in which metals are [pb_glossary id=\"1781\"]bonded[\/pb_glossary] to sulfur.\u00a0<\/span><span style=\"font-weight: 400\">Significant examples include: \u00a0<\/span>galena<span style=\"font-weight: 400\"> (lead [pb_glossary id=\"973\"]sulfide[\/pb_glossary]), <\/span>sphalerite<span style=\"font-weight: 400\"> (zinc [pb_glossary id=\"973\"]sulfide[\/pb_glossary]),<\/span> pyrite\n\n[caption id=\"attachment_2794\" align=\"alignright\" width=\"175\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.37_pyrite1.jpg\"><img class=\"wp-image-2794\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.37_pyrite1-283x300-1.jpg\" alt=\"Cubic crystals of iron pyrite, called &quot;fools gold&quot;\" width=\"175\" height=\"185\"><\/a> Cubic crystals of pyrite[\/caption]\n\n<span style=\"font-weight: 400\">(<\/span><span style=\"font-weight: 400\">iron<\/span><span style=\"font-weight: 400\">\u00a0[pb_glossary id=\"973\"]sulfide[\/pb_glossary], sometimes called \u201cfool's gold\u201d), and <\/span>chalcopyrite <span style=\"font-weight: 400\">(iron-copper [pb_glossary id=\"973\"]sulfide[\/pb_glossary]).<\/span><span style=\"font-weight: 400\">\u00a0[pb_glossary id=\"973\"]Sulfides[\/pb_glossary] are well known for being important [pb_glossary id=\"2403\"]ore[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. For example, galena is the main source of lead, sphalerite is the main source of zinc, and chalcopyrite is the main copper [pb_glossary id=\"2403\"]ore[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary] [pb_glossary id=\"2402\"]mined[\/pb_glossary] in porphyry deposits like the Bingham [pb_glossary id=\"2402\"]mine[\/pb_glossary] (see <a href=\"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/16-energy-and-mineral-resources\/\">chapter 16<\/a>). The largest sources of nickel, antimony, molybdenum, arsenic, and mercury are also [pb_glossary id=\"973\"]sulfides[\/pb_glossary].<\/span>\n<h3><b>3.4.3 Sulfates<\/b><\/h3>\n[caption id=\"attachment_2795\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.39_SeleniteGypsumUSGOV.jpg\"><img class=\"size-medium wp-image-2795\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.39_SeleniteGypsumUSGOV-300x284-1.jpg\" alt=\"A clear crystal of gypsum\" width=\"300\" height=\"284\"><\/a> Gypsum crystal[\/caption]\n\n[pb_glossary id=\"974\"]Sulfate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] contain a metal [pb_glossary id=\"2449\"]ion[\/pb_glossary], such as calcium, [pb_glossary id=\"1781\"]bonded[\/pb_glossary] to a [pb_glossary id=\"974\"]sulfate[\/pb_glossary] [pb_glossary id=\"2449\"]ion[\/pb_glossary]. The [pb_glossary id=\"974\"]sulfate[\/pb_glossary] [pb_glossary id=\"2449\"]ion[\/pb_glossary] is a combination of sulfur and oxygen (SO<sub>4<sup>-<\/sup><\/sub><sup>2<\/sup>). The [pb_glossary id=\"974\"]sulfate[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary] [pb_glossary id=\"1921\"]gypsum[\/pb_glossary] (CaSO<sub>4<\/sub>\u14272H<sub>2<\/sub>O) is used in construction materials such as plaster and drywall. [pb_glossary id=\"1921\"]Gypsum[\/pb_glossary] is often formed from evaporating water and usually contains water molecules in its crystalline structure. The \u14272H<sub>2<\/sub>O in the formula indicates the water molecules are whole H<sub>2<\/sub>O. This is different from [pb_glossary id=\"1765\"]minerals[\/pb_glossary] like [pb_glossary id=\"1791\"]amphibole[\/pb_glossary], which contain a hydroxide [pb_glossary id=\"2449\"]ion[\/pb_glossary] (OH<sup>-<\/sup>) that is derived from water, but is missing a hydrogen ion (H<sup>+<\/sup>). The calcium [pb_glossary id=\"974\"]sulfate[\/pb_glossary] without water is a different [pb_glossary id=\"1765\"]mineral[\/pb_glossary] than [pb_glossary id=\"1921\"]gypsum[\/pb_glossary] called anhydrite (CaSO<sub>4<\/sub>).\n<h3><b>3.4.4 Phosphates<\/b><\/h3>\n[caption id=\"attachment_2796\" align=\"alignright\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.40_Apatite_Canada.jpg\"><img class=\"wp-image-2796\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.40_Apatite_Canada-236x300-1.jpg\" alt=\"A crystal of apatite\" width=\"150\" height=\"191\"><\/a> Apatite crystal[\/caption]\n\n<span style=\"font-weight: 400\">[pb_glossary id=\"975\"]Phosphate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] have a tetrahedral [pb_glossary id=\"975\"]phosphate[\/pb_glossary] unit (PO<sub>4<\/sub><sup>-3<\/sup>) combined with various [pb_glossary id=\"1782\"]anions[\/pb_glossary] and [pb_glossary id=\"1780\"]cations[\/pb_glossary]. In some cases arsenic or vanadium can substitute for phosphorus. [pb_glossary id=\"975\"]Phosphates[\/pb_glossary] are an important ingredient of fertilizers as well as detergents, paint, and other products. The best known [pb_glossary id=\"975\"]phosphate[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary] is apatite, Ca<sub>5<\/sub>(PO<sub>4<\/sub>)<sub>3<\/sub>(F,Cl,OH), variations of which are found in teeth and bones. The gemstone turquoise [CuAl<sub>6<\/sub>(PO<sub>4<\/sub>)<sub>4<\/sub>(OH)<sub>8<\/sub>\u00b74H2O ] is a copper-rich [pb_glossary id=\"975\"]phosphate[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary] that, like [pb_glossary id=\"1921\"]gypsum[\/pb_glossary], contains water molecules.<\/span>\n<h3><b>3.4.5 Native Element Minerals<\/b><\/h3>\n[caption id=\"attachment_2798\" align=\"alignleft\" width=\"200\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.43_Sulfer_Fumarola_Vulcano.jpg\"><img class=\"wp-image-2798\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.43_Sulfer_Fumarola_Vulcano-300x225-1.jpg\" alt=\"Native sulfur deposited around the vent of a volcanic fumarole\" width=\"200\" height=\"150\"><\/a> Native sulfur deposited around a volcanic fumarole[\/caption]\n\n[caption id=\"attachment_2797\" align=\"alignright\" width=\"200\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.41_Native_Copper-1.jpg\"><img class=\"wp-image-2797\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.41_Native_Copper-1-300x284-1.jpg\" alt=\"Metallic native copper\" width=\"200\" height=\"189\"><\/a> Native copper[\/caption]\n\n[pb_glossary id=\"976\"]Native element minerals[\/pb_glossary], usually metals, occur in nature in a pure or nearly pure state. Gold is an example of a [pb_glossary id=\"976\"]native[\/pb_glossary] [pb_glossary id=\"1778\"]element[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary]; it is not very reactive and rarely [pb_glossary id=\"1781\"]bonds[\/pb_glossary] with other [pb_glossary id=\"1778\"]elements[\/pb_glossary] so it is usually found in an isolated or pure state. The non-[pb_glossary id=\"2423\"]metallic[\/pb_glossary] and poorly-reactive [pb_glossary id=\"1765\"]mineral[\/pb_glossary] carbon is often found as a [pb_glossary id=\"976\"]native[\/pb_glossary] [pb_glossary id=\"1778\"]element[\/pb_glossary], such as graphite and diamonds. Mildly reactive metals like silver, copper, platinum, mercury, and sulfur sometimes occur as [pb_glossary id=\"976\"]native element minerals[\/pb_glossary]. Reactive metals such as iron, lead, and aluminum almost always [pb_glossary id=\"1781\"]bond[\/pb_glossary] to other [pb_glossary id=\"1778\"]elements[\/pb_glossary] and are rarely found in a [pb_glossary id=\"976\"]native[\/pb_glossary] state.\n<h3><\/h3>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"20\"]\n\n[caption id=\"attachment_3751\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.4-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-191\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 3.4 via this QR Code.[\/caption]\n<h2><span style=\"font-weight: 400\">3.5 Identifying Minerals<\/span><\/h2>\n[caption id=\"attachment_2799\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Curiosity_Mars_Rover_Finds_Mineral_Match.jpg\"><img class=\"size-medium wp-image-2799\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Curiosity_Mars_Rover_Finds_Mineral_Match-300x268-1.jpg\" alt=\"The red rocks have a small hole drilled\" width=\"300\" height=\"268\"><\/a> The rover Curiosity drilled a hole in this rock from Mars, and confirmed the mineral Hematite, as mapped from satellites.[\/caption]\n\nGeologists identify [pb_glossary id=\"1765\"]minerals[\/pb_glossary] by their physical properties. In the field, where geologists may have limited access to advanced technology and powerful machines, they can still identify [pb_glossary id=\"1765\"]minerals[\/pb_glossary] by testing several physical properties: [pb_glossary id=\"977\"]luster[\/pb_glossary] and color, [pb_glossary id=\"978\"]streak[\/pb_glossary], [pb_glossary id=\"979\"]hardness[\/pb_glossary], [pb_glossary id=\"980\"]crystal habit[\/pb_glossary], cleavage and [pb_glossary id=\"986\"]fracture[\/pb_glossary], and some special properties. Only a few common [pb_glossary id=\"1765\"]minerals[\/pb_glossary] make up the majority of Earth's rocks and are usually seen as small grains in rocks. Of the several properties used for identifying [pb_glossary id=\"1765\"]minerals[\/pb_glossary], it is good to consider which will be most useful for identifying them in small grains surrounded by other [pb_glossary id=\"1765\"]minerals[\/pb_glossary].\n<h3><b>3.5.1 Luster and Color<\/b><\/h3>\n[caption id=\"attachment_2800\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Molly_Hill_molybdenite.jpg\"><img class=\"size-medium wp-image-2800\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Molly_Hill_molybdenite-300x225-1.jpg\" alt=\"The crystal looks like metal.\" width=\"300\" height=\"225\"><\/a> 15 mm metallic hexagonal molybdenite crystal from Quebec.[\/caption]\n\n&nbsp;\n\nThe first thing to notice about a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] is its surface appearance, specifically [pb_glossary id=\"977\"]luster[\/pb_glossary] and color. [pb_glossary id=\"977\"]Luster[\/pb_glossary] describes how the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] looks. [pb_glossary id=\"2423\"]Metallic[\/pb_glossary] [pb_glossary id=\"977\"]luster[\/pb_glossary] looks like a shiny metal such as chrome, steel, silver, or gold. Submetallic [pb_glossary id=\"977\"]luster[\/pb_glossary] has a duller appearance. Pewter, for example, shows submetallic [pb_glossary id=\"977\"]luster[\/pb_glossary].\n\n[caption id=\"attachment_2801\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Pewter-plate.jpg\"><img class=\"size-medium wp-image-2801\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Pewter-plate-300x280-1.jpg\" alt=\"Antique pewter plate showing a more dull submetallic luster\" width=\"300\" height=\"280\"><\/a> Submetallic luster shown on an antique pewter plate.[\/caption]\n\n&nbsp;\n\n&nbsp;\n\n[pb_glossary id=\"2424\"]Nonmetallic[\/pb_glossary] [pb_glossary id=\"977\"]luster[\/pb_glossary] doesn\u2019t look like a metal and may be described as vitreous (glassy), earthy, silky, pearly, and other surface qualities. [pb_glossary id=\"2424\"]Nonmetallic[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] may be shiny, although their vitreous shine is different from [pb_glossary id=\"2423\"]metallic[\/pb_glossary] [pb_glossary id=\"977\"]luster[\/pb_glossary]. See the table for descriptions and examples of [pb_glossary id=\"2424\"]nonmetallic[\/pb_glossary] [pb_glossary id=\"977\"]luster[\/pb_glossary].\n<table style=\"width: 680px;height: 859px\">\n<tbody>\n<tr style=\"height: 32.625px\">\n<th style=\"border-color: #000000;background-color: #1ae8de;text-align: center;vertical-align: middle\"><span style=\"text-decoration: underline\">[pb_glossary id=\"977\"]Luster[\/pb_glossary]<\/span><\/th>\n<th style=\"border-color: #000000;background-color: #1ae8de;text-align: center;vertical-align: middle\"><span style=\"text-decoration: underline\">Image<\/span><\/th>\n<th style=\"border-color: #000000;background-color: #1ae8de;text-align: center;vertical-align: middle\"><span style=\"text-decoration: underline\">Description<\/span><\/th>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Vitreous\/glassy<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_3669\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.23_-Quartz_Bresil.jpg\"><img class=\"size-thumbnail wp-image-195\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.23_-Quartz_Bresil-150x150.jpg\" alt=\"A mass of quartz crystals showing typical six sided habit with points\" width=\"150\" height=\"150\"><\/a> Quartz crystals[\/caption]<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Surface is shiny like glass<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Earthy\/dull<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2802\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.47_earthy_luster_KaolinUSGOV-1.jpg\"><img class=\"size-thumbnail wp-image-2802\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.47_earthy_luster_KaolinUSGOV-1-150x150-1.jpg\" alt=\"Specimen of kaolin, a clay oineral, showing dull or earthy luster\" width=\"150\" height=\"150\"><\/a> Kaolin specimen showing dull or earthy luster[\/caption]<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Dull, like dried mud or clay<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Silky<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2803\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.48_silky_luster_Selenite_Gips_Marienglas-1.jpg\"><img class=\"wp-image-2803\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.48_silky_luster_Selenite_Gips_Marienglas-1-300x230-1.jpg\" alt=\"Specimen showing silky luster\" width=\"150\" height=\"115\"><\/a> Specimen showing silky luster[\/caption]<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Soft shine like silk fabric<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Pearly<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2804\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.49_pearly_luster_Mineral_Mica_GDFL006.jpg\"><img class=\"wp-image-2804\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.49_pearly_luster_Mineral_Mica_GDFL006-300x218-1.jpg\" alt=\"Specimen showing pearly luster like the inside of a clam shell\" width=\"150\" height=\"109\"><\/a> Specimen showing pearly luster[\/caption]<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Like the inside of a clam shell or mother-of-pearl<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Submetallic<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2805\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.44_submetallic_Sphalerite4.jpg\"><img class=\"wp-image-2805\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.44_submetallic_Sphalerite4-300x277-1.jpg\" alt=\"Photo of mineral exhibiting submetallic luster\" width=\"150\" height=\"138\"><\/a> Submetallic luster on sphalerite[\/caption]<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Has the appearance of dull metal,\u00a0like pewter. These [pb_glossary id=\"1765\"]minerals[\/pb_glossary] would usually still be considered [pb_glossary id=\"2423\"]metallic[\/pb_glossary]. Submetallic appearance can occur in [pb_glossary id=\"2423\"]metallic[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] because of [pb_glossary id=\"1754\"]weathering[\/pb_glossary].<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n[caption id=\"attachment_2806\" align=\"alignleft\" width=\"245\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Azurite_in_siltstone_Malbunka_mine_NT.jpg\"><img class=\"size-medium wp-image-2806\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Azurite_in_siltstone_Malbunka_mine_NT-245x300-1.jpg\" alt=\"There are two dark blue disks on white siltstone.\" width=\"245\" height=\"300\"><\/a> Azurite is ALWAYS a dark blue color, and has been used for centuries for blue pigment.[\/caption]\n\nSurface color may be helpful in identifying [pb_glossary id=\"1765\"]minerals[\/pb_glossary], although it can be quite variable within the same [pb_glossary id=\"1765\"]mineral[\/pb_glossary] family. [pb_glossary id=\"1765\"]Mineral[\/pb_glossary] colors are affected by the main [pb_glossary id=\"1778\"]elements[\/pb_glossary] as well as impurities in the crystals. These impurities may be rare [pb_glossary id=\"1778\"]elements[\/pb_glossary]\u2014like manganese, titanium, chromium, or lithium\u2014even other molecules that are not normally part of the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] formula. For example, the incorporation of water molecules gives [pb_glossary id=\"967\"]quartz[\/pb_glossary], which is normally clear, a milky color.\n\nSome [pb_glossary id=\"1765\"]minerals[\/pb_glossary] predominantly show a single color. Malachite and azurite are green and blue, respectively, because of their copper content. Other [pb_glossary id=\"1765\"]minerals[\/pb_glossary] have a predictable range of colors due to elemental substitutions, usually via a [pb_glossary id=\"1786\"]solid solution[\/pb_glossary]. [pb_glossary id=\"968\"]Feldspars[\/pb_glossary], the most abundant [pb_glossary id=\"1765\"]minerals[\/pb_glossary] in the earth\u2019s [pb_glossary id=\"1658\"]crust[\/pb_glossary], are complex, have [pb_glossary id=\"1786\"]solid solution[\/pb_glossary] series, and present several colors including pink, white, green, gray and others. Other [pb_glossary id=\"1765\"]minerals[\/pb_glossary] also come in several colors, influenced by trace amounts of several [pb_glossary id=\"1778\"]elements[\/pb_glossary]. The same [pb_glossary id=\"1778\"]element[\/pb_glossary] may show up as different colors, in different [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. With notable exceptions, color is usually not a definitive property of [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. For identifying many [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. a more reliable indicator is [pb_glossary id=\"978\"]streak[\/pb_glossary], which is the color of the powdered [pb_glossary id=\"1765\"]mineral[\/pb_glossary].\n<h3><b>3.5.2 Streak<\/b><\/h3>\n[caption id=\"attachment_2807\" align=\"alignright\" width=\"450\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.50_Streak_plate_with_Pyrite_and_Rhodochrosite-1-scaled.jpg\"><img class=\"wp-image-2807\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.50_Streak_plate_with_Pyrite_and_Rhodochrosite-1-300x227-1.jpg\" alt=\"Pyrite showing a black streak on a white streak plate and rhodochrosite with a white streak on a black streak plate\" width=\"450\" height=\"341\"><\/a> Different minerals may have different streaks[\/caption]\n\n[pb_glossary id=\"978\"]Streak[\/pb_glossary] examines the color of a powdered [pb_glossary id=\"1765\"]mineral[\/pb_glossary], and can be seen when a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] sample is scratched or scraped on an unglazed porcelain [pb_glossary id=\"978\"]streak[\/pb_glossary] [pb_glossary id=\"1669\"]plate[\/pb_glossary]. A paper page in a field notebook may also be used for the [pb_glossary id=\"978\"]streak[\/pb_glossary] of some [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. [pb_glossary id=\"1765\"]Minerals[\/pb_glossary] that are harder than the [pb_glossary id=\"978\"]streak[\/pb_glossary] [pb_glossary id=\"1669\"]plate[\/pb_glossary] will not show [pb_glossary id=\"978\"]streak[\/pb_glossary], but will scratch the porcelain. For these [pb_glossary id=\"1765\"]minerals[\/pb_glossary], a [pb_glossary id=\"978\"]streak[\/pb_glossary] test can be obtained by powdering the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] with a hammer and smearing the powder across a [pb_glossary id=\"978\"]streak[\/pb_glossary] [pb_glossary id=\"1669\"]plate[\/pb_glossary] or notebook paper.\n\nWhile [pb_glossary id=\"1765\"]mineral[\/pb_glossary] surface colors and appearances may vary, their [pb_glossary id=\"978\"]streak[\/pb_glossary] colors can be diagnostically useful. An example of this property is seen in the iron-[pb_glossary id=\"971\"]oxide[\/pb_glossary] [pb_glossary id=\"1765\"]mineral[\/pb_glossary] hematite. Hematite occurs in a variety of forms, colors and lusters, from shiny [pb_glossary id=\"2423\"]metallic[\/pb_glossary] silver to earthy red-brown, and different physical appearances. A hematite [pb_glossary id=\"978\"]streak[\/pb_glossary] is consistently reddish brown, no matter what the original specimen looks like. Iron [pb_glossary id=\"973\"]sulfide[\/pb_glossary] or pyrite, is a brassy [pb_glossary id=\"2423\"]metallic[\/pb_glossary] yellow. Commonly named fool\u2019s gold, pyrite has a characteristic black to greenish-black [pb_glossary id=\"978\"]streak[\/pb_glossary].\n<h3><b>3.5.3 Hardness<\/b><\/h3>\n[caption id=\"attachment_2808\" align=\"aligncenter\" width=\"1024\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.51_Mohs_Scale2.jpg\"><img class=\"size-large wp-image-2808\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.51_Mohs_Scale2-1024x714-1.jpg\" alt=\"Chart of Mohs Hardness Scale with minerals arranged in hardness from 1 to 10, also showing common items that correlate with the scale.\" width=\"1024\" height=\"714\"><\/a> Mohs Hardness Scale[\/caption]\n\n[pb_glossary id=\"979\"]Hardness[\/pb_glossary] measures the ability of a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] to scratch other substances. The Mohs [pb_glossary id=\"979\"]Hardness[\/pb_glossary] Scale gives a number showing the relative scratch-resistance of [pb_glossary id=\"1765\"]minerals[\/pb_glossary] when compared to a standardized set of [pb_glossary id=\"1765\"]minerals[\/pb_glossary] of increasing hardness. The Mohs scale was developed by German geologist Fredrick Mohs in the early 20th century, although the idea of identifying [pb_glossary id=\"1765\"]minerals[\/pb_glossary] by [pb_glossary id=\"979\"]hardness[\/pb_glossary] goes back thousands of years. Mohs [pb_glossary id=\"979\"]hardness[\/pb_glossary] values are determined by the strength of a [pb_glossary id=\"1765\"]mineral[\/pb_glossary]\u2019s atomic [pb_glossary id=\"1781\"]bonds[\/pb_glossary].\n\nThe figure shows the [pb_glossary id=\"1765\"]minerals[\/pb_glossary] associated with specific [pb_glossary id=\"979\"]hardness[\/pb_glossary] values, together with some common items readily available for use in field testing and [pb_glossary id=\"1765\"]mineral[\/pb_glossary] identification. The [pb_glossary id=\"979\"]hardness[\/pb_glossary] values run from 1 to 10, with 10 being the hardest; however, the scale is not linear. Diamond defines a [pb_glossary id=\"979\"]hardness[\/pb_glossary] of 10 and is actually about four times harder than corundum, which is 9. A steel pocketknife blade, which has a [pb_glossary id=\"979\"]hardness[\/pb_glossary] value of 5.5, separates between hard and soft [pb_glossary id=\"1765\"]minerals[\/pb_glossary] on many [pb_glossary id=\"1765\"]mineral[\/pb_glossary] identification keys.\n<h3><b>3.5.4 Crystal Habit<\/b><\/h3>\n[pb_glossary id=\"1765\"]Minerals[\/pb_glossary] can be identified by <strong>[pb_glossary id=\"980\"]crystal habit[\/pb_glossary]<\/strong>, how their crystals grow and appear in rocks. Crystal shapes are determined by the arrangement of the atoms within the crystal structure. For example, a cubic arrangement of atoms gives rise to a cubic-shaped [pb_glossary id=\"1765\"]mineral[\/pb_glossary] crystal. [pb_glossary id=\"980\"]Crystal habit[\/pb_glossary] refers to typically observed shapes and characteristics; however, they can be affected by other [pb_glossary id=\"1765\"]minerals[\/pb_glossary] crystallizing in the same rock. When [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are constrained so they do not develop their typical [pb_glossary id=\"980\"]crystal habit[\/pb_glossary], they are called <strong>[pb_glossary id=\"981\"]anhedral[\/pb_glossary]<\/strong>. <strong>[pb_glossary id=\"982\"]Subhedral[\/pb_glossary]<\/strong> crystals are partially formed shapes. For some [pb_glossary id=\"1765\"]minerals[\/pb_glossary] characteristic [pb_glossary id=\"980\"]crystal habit[\/pb_glossary] is to grow crystal faces even when surrounded by other crystals in rock. An example is garnet. [pb_glossary id=\"1765\"]Minerals[\/pb_glossary] grown freely where the crystals are unconstrained and can take characteristic shapes often form crystal faces. A <strong>[pb_glossary id=\"983\"]euhedral[\/pb_glossary]<\/strong> crystal has a perfectly formed, unconstrained shape. Some [pb_glossary id=\"1765\"]minerals[\/pb_glossary] crystallize in such tiny crystals, they do not show a specific [pb_glossary id=\"980\"]crystal habit[\/pb_glossary] to the naked eye. Other [pb_glossary id=\"1765\"]minerals[\/pb_glossary], like pyrite, can have an array of different crystal habits, including cubic, dodecahedral, octahedral, and [pb_glossary id=\"985\"]massive[\/pb_glossary]. The table lists typical crystal habits of various [pb_glossary id=\"1765\"]minerals[\/pb_glossary].\n<table style=\"width: 687px;height: 3774px\">\n<tbody>\n<tr>\n<th style=\"border-color: #000000;background-color: #6be86f;text-align: center;vertical-align: middle\" scope=\"row\"><strong><span style=\"text-decoration: underline\">[pb_glossary id=\"980\"]Habit[\/pb_glossary]<\/span><\/strong><\/th>\n<th style=\"border-color: #000000;background-color: #6be86f;text-align: center;vertical-align: middle\" scope=\"row\"><strong><span style=\"text-decoration: underline\">Image<\/span><\/strong><\/th>\n<th style=\"border-color: #000000;background-color: #6be86f;text-align: center;vertical-align: middle\" scope=\"row\"><strong><span style=\"text-decoration: underline\">Examples<\/span><\/strong><\/th>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Bladed<\/strong>\n\nlong and flat crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2809\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Kyanite_crystals.jpg\"><img class=\"wp-image-2809\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Kyanite_crystals-300x225-1.jpg\" alt=\"The crystals are long and rectangular\" width=\"150\" height=\"113\"><\/a> Bladed kyanite[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">kyanite,\u00a0[pb_glossary id=\"1791\"]amphibole[\/pb_glossary], [pb_glossary id=\"1921\"]gypsum[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Botryoidal\/mammillary<\/strong>\n\nblobby, circular crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2810\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Malachite_Kolwezi_Katanga_Congo.jpg\"><img class=\"wp-image-2810\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Malachite_Kolwezi_Katanga_Congo-300x174-1.jpg\" alt=\"The mineral is bulbous\" width=\"150\" height=\"87\"><\/a> Malachite from the Congo[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">hematite, malachite, smithsonite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Coating\/[pb_glossary id=\"1938\"]laminae[\/pb_glossary]\/druse<\/strong>\n\ncrystals that are small and coat surfaces<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2811\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ametyst-geode.jpg\"><img class=\"wp-image-2811\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ametyst-geode-300x200-1.jpg\" alt=\"The rock is hollowed and filled with purple minerals\" width=\"150\" height=\"100\"><\/a> Quartz (var. amethyst) geode[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">[pb_glossary id=\"967\"]quartz[\/pb_glossary], [pb_glossary id=\"970\"]calcite[\/pb_glossary], malachite, azurite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Cubic<\/strong>\n\ncube-shaped crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2812\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.55_Cubic_Calcite-Galena-elm56c.jpg\"><img class=\"wp-image-2812\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.55_Cubic_Calcite-Galena-elm56c-260x300-1.jpg\" alt=\"Cubic crystals of galena, a sulfide of lead\" width=\"150\" height=\"173\"><\/a> Cubic crystals of galena[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">pyrite, galena, [pb_glossary id=\"1922\"]halite[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Dodecahedral<\/strong>\n\n12-sided polygon shapes<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2813\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.53_habit_dodecahedral_Pyrite_elbe-scaled.jpg\"><img class=\"wp-image-2813\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.53_habit_dodecahedral_Pyrite_elbe-300x195-1.jpg\" alt=\"Crystals of pyrite showing dodecahedral habit\" width=\"150\" height=\"97\"><\/a> Pyrite crystals with dodecahedral habit[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">garnet, pyrite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Dendritic<\/strong>\n\nbranching crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2814\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Dendrites01.jpg\"><img class=\"wp-image-2814\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Dendrites01-300x203-1.jpg\" alt=\"The mineral look like a fern. They are black and branching.\" width=\"150\" height=\"101\"><\/a> Manganese dendrites, scale in mm.[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">Mn-[pb_glossary id=\"971\"]oxides[\/pb_glossary], copper, gold<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>[pb_glossary id=\"984\"]Equant[\/pb_glossary]<\/strong>\n\ncrystals that do not have a long direction<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2815\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Peridot2.jpg\"><img class=\"wp-image-209\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2-272x300.jpg\" alt=\"The crystal is light green.\" width=\"150\" height=\"165\"><\/a> Large olivine crystal[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">[pb_glossary id=\"1789\"]olivine[\/pb_glossary], garnet, [pb_glossary id=\"1790\"]pyroxene[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Fibrous<\/strong>\n\nthin, very long crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2816\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tremolite_Campolungo.jpg\"><img class=\"wp-image-2816\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tremolite_Campolungo-300x186-1.jpg\" alt=\"It is white and fiberous\" width=\"150\" height=\"93\"><\/a> Tremolite, a type of amphibole[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">serpentine, [pb_glossary id=\"1791\"]amphibole[\/pb_glossary], zeolite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Layered, sheets<\/strong>\n\nstacked, very thin, flat crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2817\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.18_Muscovite-Albite-122887.jpg\"><img class=\"wp-image-2817\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.18_Muscovite-Albite-122887-300x254-1.jpg\" alt=\"Sheets of muscovite mica in crystal mass\" width=\"150\" height=\"127\"><\/a> Sheet crystals of muscovite[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">[pb_glossary id=\"966\"]mica [\/pb_glossary]([pb_glossary id=\"966\"]biotite[\/pb_glossary], [pb_glossary id=\"966\"]muscovite[\/pb_glossary], etc.)<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Lenticular\/platy<\/strong>\n\ncrystals that are [pb_glossary id=\"1669\"]plate[\/pb_glossary]-like<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2818\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Calcite-Wulfenite-tcw15b.jpg\"><img class=\"wp-image-2818\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-Wulfenite-tcw15b-251x300-1.jpg\" alt=\"The orange wulfenite is bladed\" width=\"150\" height=\"179\"><\/a> Orange wulfenite on calcite[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">selenite roses, wulfenite, [pb_glossary id=\"970\"]calcite[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Hexagonal<\/strong>\n\ncrystals with six sides<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_3687\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Hanksite-1.jpg\"><img class=\"wp-image-213 size-thumbnail\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hanksite-1-150x150.jpg\" alt=\"The mineral is hexagonal and clear.\" width=\"150\" height=\"150\"><\/a> Hexagonal hanksite[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">[pb_glossary id=\"967\"]quartz[\/pb_glossary], hanksite, corundum<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>[pb_glossary id=\"985\"]Massive[\/pb_glossary]\/granular<\/strong>\n\nCrystals with no obvious shape, microscopic crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2789\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.31_Iron_oxide_LimoniteUSGOV.jpg\"><img class=\"wp-image-2789\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.31_Iron_oxide_LimoniteUSGOV-300x256-1.jpg\" alt=\"Image of limonite, a hydrated oxide of iron\" width=\"150\" height=\"128\"><\/a> Limonite, a hydrated oxide of iron[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">limonite, pyrite, azurite, bornite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Octahedral<\/strong>\n\n4-sided double pyramid crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2819\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.62_octahedral_cleavage_Fluorite_crystals_rotated_90.jpg\"><img class=\"wp-image-2819\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.62_octahedral_cleavage_Fluorite_crystals_rotated_90-300x182-1.jpg\" alt=\"Perfedt octahedral cleavage in fluorite generates octagon-shaped cleavage flakes.\" width=\"150\" height=\"91\"><\/a> Octagonal cleavage in fluorite[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">diamond, fluorite, magnetite, pyrite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Prismatic\/columnar<\/strong>\n\nvery long, cylindrical crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2820\" align=\"aligncenter\" width=\"142\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tourmaline.jpg\"><img class=\"size-medium wp-image-2820\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tourmaline-142x300-1.jpg\" alt=\"The mineral is a long cylinder.\" width=\"142\" height=\"300\"><\/a> Columnar tourmaline[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">tourmaline, beryl, barite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Radiating<\/strong>\n\ncrystals that grow from a point and fan out<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2821\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Pyrophyllite-236595.jpg\"><img class=\"wp-image-2821\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Pyrophyllite-236595-217x300-1.jpg\" alt=\"The mineral is orange\" width=\"150\" height=\"207\"><\/a> Pyrophyllite[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">pyrite \"suns\", pyrophyllite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Rhombohedral<\/strong>\n\ncrystals shaped like slanted cubes<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2785\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.26_Calcite-rhomb.jpg\"><img class=\"wp-image-2785\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.26_Calcite-rhomb-245x300-1.jpg\" alt=\"Calcite crystal in a shape called a rhomb like a cube squahed over toward one corner\" width=\"150\" height=\"183\"><\/a> Calcite crystal in shape of rhomb.[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">[pb_glossary id=\"970\"]calcite[\/pb_glossary], dolomite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Tabular\/blocky\/stubby<\/strong>\n\nsharp-sided crystals with no long direction<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2770\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.14_Diopside-172005.jpg\"><img class=\"wp-image-2770\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.14_Diopside-172005-300x231-1.jpg\" alt=\"Dark green crystals of diopside, a member of the pyroxene family\" width=\"150\" height=\"116\"><\/a> Crystals of diopside, a member of the pyroxene family[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">[pb_glossary id=\"968\"]feldspar[\/pb_glossary], [pb_glossary id=\"1790\"]pyroxene[\/pb_glossary], [pb_glossary id=\"970\"]calcite[\/pb_glossary]<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Tetrahedral<\/strong>\n\nthree-sided, pyramid-shaped crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n\n[caption id=\"attachment_2822\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tetrahedrite-Chalcopyrite-Sphalerite-251531.jpg\"><img class=\"wp-image-2822\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tetrahedrite-Chalcopyrite-Sphalerite-251531-300x218-1.jpg\" alt=\"The dark brown mineral is triangular\" width=\"150\" height=\"109\"><\/a> Tetrahedrite[\/caption]<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">magnetite, spinel, tetrahedrite<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n&nbsp;\n\n[caption id=\"attachment_2824\" align=\"alignleft\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/GypsumStriations.jpg\"><img class=\"wp-image-2824\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/GypsumStriations-251x300-1.jpg\" alt=\"The mineral has many parallel lines on it\" width=\"150\" height=\"179\"><\/a> Gypsum with striations[\/caption]\n\n&nbsp;\n\n[caption id=\"attachment_2823\" align=\"alignright\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Staurolite-62645.jpg\"><img class=\"wp-image-2823\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Staurolite-62645-279x300-1.jpg\" alt=\"The brown minerals are replicated in different directions\" width=\"150\" height=\"161\"><\/a> Twinned staurolite[\/caption]\n\nAnother [pb_glossary id=\"980\"]crystal habit[\/pb_glossary] that may be used to identify [pb_glossary id=\"1765\"]minerals[\/pb_glossary] is striations, which are dark and light parallel lines on a crystal face. Twinning is another, which occurs when the crystal structure replicates in mirror images along certain directions in the crystal.\n\n[caption id=\"attachment_2825\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.65_Striations_in_plagioclase.jpg\"><img class=\"size-medium wp-image-2825\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.65_Striations_in_plagioclase-300x242-1.jpg\" alt=\"Striations or parallel dark lines on one cleavage surface on plagioclase feldspar\" width=\"300\" height=\"242\"><\/a> Striations on plagioclase[\/caption]\n\n&nbsp;\n\nStriations and twinning are related properties in some [pb_glossary id=\"1765\"]minerals[\/pb_glossary] including [pb_glossary id=\"968\"]plagioclase[\/pb_glossary] [pb_glossary id=\"968\"]feldspar[\/pb_glossary]. Striations are optical lines on a cleavage surface. Because of twinning in the crystal, striations show up on one of the two cleavage faces of the [pb_glossary id=\"968\"]plagioclase[\/pb_glossary] crystal.\n<h3><b>3.5.5 Cleavage and Fracture<\/b><\/h3>\n[pb_glossary id=\"1765\"]Minerals[\/pb_glossary] often show characteristic patterns of breaking along specific cleavage planes or show characteristic [pb_glossary id=\"986\"]fracture[\/pb_glossary] patterns. Cleavage planes are smooth, flat, parallel planes within the crystal. The cleavage planes may show as reflective surfaces on the crystal, as parallel cracks that penetrate into the crystal, or show on the edge or side of the crystal as a series of steps like rice [pb_glossary id=\"2240\"]terraces[\/pb_glossary]. Cleavage arises in crystals where the atomic [pb_glossary id=\"1781\"]bonds[\/pb_glossary] between atomic layers are weaker along some directions than others, meaning they will break preferentially along these planes.\u00a0Because they develop on atomic surfaces in the crystal, cleavage planes are optically smooth and reflect light, although the actual break on the crystal may appear jagged or uneven. In such cleavages, the cleavage surface may appear like rice [pb_glossary id=\"2240\"]terraces[\/pb_glossary] on a mountainside that all reflect sunlight from a particular sun angle. Some [pb_glossary id=\"1765\"]minerals[\/pb_glossary] have a strong cleavage, some [pb_glossary id=\"1765\"]minerals[\/pb_glossary] only have weak cleavage or do not typically demonstrate cleavage.\n\n[caption id=\"attachment_2826\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.57_conchoidal_Citrine-sample2.jpg\"><img class=\"size-medium wp-image-2826\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.57_conchoidal_Citrine-sample2-300x225-1.jpg\" alt=\"A specimen of a variety of quartz showing conchoidal fracture\" width=\"300\" height=\"225\"><\/a> Citrine, a variety of quartz showing conchoidal fracture[\/caption]\n\nFor example, [pb_glossary id=\"967\"]quartz[\/pb_glossary] and [pb_glossary id=\"1789\"]olivine[\/pb_glossary] rarely show cleavage and typically break into [pb_glossary id=\"987\"]conchoidal[\/pb_glossary] [pb_glossary id=\"986\"]fracture[\/pb_glossary] patterns.\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n[caption id=\"attachment_2827\" align=\"alignleft\" width=\"452\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/cryview_graphite_v1.gif\"><img class=\"wp-image-2827 size-full\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/cryview_graphite_v1.gif\" alt=\"Structure of graphite, showing single carbon layers with weak bonds holding them together\" width=\"452\" height=\"504\"><\/a> Graphite showing layers of carbon atoms separated by a gap with weak bonds holding the layers together.[\/caption]\n\nGraphite has its carbon atoms arranged into layers with relatively strong [pb_glossary id=\"1781\"]bonds[\/pb_glossary] within the layer and very weak [pb_glossary id=\"1781\"]bonds[\/pb_glossary] between the layers.\u00a0 Thus graphite cleaves readily between the layers and the layers slide easily over one another giving graphite its lubricating quality.\n\n&nbsp;\n\n&nbsp;\n\n&nbsp;\n\n[pb_glossary id=\"1765\"]Mineral[\/pb_glossary] [pb_glossary id=\"986\"]fracture[\/pb_glossary] surfaces may be rough and uneven or they may be show [pb_glossary id=\"987\"]conchoidal[\/pb_glossary] [pb_glossary id=\"986\"]fracture[\/pb_glossary]. Uneven [pb_glossary id=\"986\"]fracture[\/pb_glossary] patterns are described as irregular, splintery, fibrous. A conchoidal fracture has a smooth, curved surface like a shallow bowl or conch shell, often with curved ridges. Natural [pb_glossary id=\"228\"]volcanic[\/pb_glossary] glass, called [pb_glossary id=\"999\"]obsidian[\/pb_glossary], breaks with this characteristic [pb_glossary id=\"987\"]conchoidal[\/pb_glossary] pattern\n\n&nbsp;\n\n[caption id=\"attachment_2828\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.64_galena_cleavage_Argentiferous_Galena-458851.jpg\"><img class=\"wp-image-2828 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.64_galena_cleavage_Argentiferous_Galena-458851-300x261-1.jpg\" alt=\"Specimen of galena showing cubic cleavage\" width=\"300\" height=\"261\"><\/a> Cubic cleavage of galena; note how the cleavage surfaces show up as different but parallel layers in the crystal.[\/caption]\n\n&nbsp;\n\nTo work with cleavage, it is important to remember that cleavage is a result of [pb_glossary id=\"1781\"]bonds[\/pb_glossary] separating along planes of atoms in the crystal structure. On some [pb_glossary id=\"1765\"]minerals[\/pb_glossary], <strong>cleavage planes<\/strong> may be confused with crystal faces. This will usually not be an issue for crystals of [pb_glossary id=\"1765\"]minerals[\/pb_glossary] that grew together within rocks. The act of breaking the rock to expose a fresh face will most likely break the crystals along cleavage planes. Some cleavage planes are parallel with crystal faces but many are not.\u00a0Cleavage planes are smooth, flat, parallel planes within the crystal. The cleavage planes may show as parallel cracks that penetrate into the crystal (see [pb_glossary id=\"1791\"]amphibole[\/pb_glossary] below), or show on the edge or side of the crystal as a series of steps like rice [pb_glossary id=\"2240\"]terraces[\/pb_glossary]. For some [pb_glossary id=\"1765\"]minerals[\/pb_glossary] characteristic [pb_glossary id=\"980\"]crystal habit[\/pb_glossary] is to grow crystal faces even when surrounded by other crystals in rock. An example is garnet. [pb_glossary id=\"1765\"]Minerals[\/pb_glossary] grown freely where the crystals are unconstrained and can take characteristic shapes often form crystal faces (see [pb_glossary id=\"967\"]quartz[\/pb_glossary] below).\n\n[caption id=\"attachment_2829\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Quartz-crystals.jpg\"><img class=\"size-medium wp-image-2829\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Quartz-crystals-300x284-1.jpg\" alt=\"Freely grown quartz crystals showing crysatl faces\" width=\"300\" height=\"284\"><\/a> Freely growing quartz crystals showing crystal faces[\/caption]\n\n<span style=\"font-weight: 400\">In some [pb_glossary id=\"1765\"]minerals[\/pb_glossary], distinguishing cleavage planes from crystal faces may be challenging for the student. Understanding the nature of cleavage and referring to the number of cleavage planes and cleavage angles on identification keys should provide the student with enough information to distinguish cleavages from crystal faces. Cleavage planes may show as multiple parallel cracks or flat surfaces on the crystal. Cleavage planes may be expressed as a series of steps like terraced rice paddies. See the cleavage surfaces on galena above or [pb_glossary id=\"968\"]plagioclase[\/pb_glossary] below. Cleavage planes arise from the tendency of [pb_glossary id=\"1765\"]mineral[\/pb_glossary] crystals to break along specific planes of weakness within the crystal favored by atomic arrangements. The number of cleavage planes, the quality of the cleavage surfaces, and the angles between them are diagnostic for many [pb_glossary id=\"1765\"]minerals[\/pb_glossary] and cleavage is one of the most useful properties for identifying [pb_glossary id=\"1765\"]minerals[\/pb_glossary]. Learning to recognize cleavage is an especially important and useful skill in studying [pb_glossary id=\"1765\"]minerals[\/pb_glossary].<\/span>\n\n[caption id=\"attachment_2830\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.61_Cleavage_steps_in_wollastonite.jpg\"><img class=\"size-medium wp-image-2830\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.61_Cleavage_steps_in_wollastonite-300x224-1.jpg\" alt=\"Image of wollastonite, a crystal showing step-like cleavage on one side. All steps are along the same direction of cleavage.\" width=\"300\" height=\"224\"><\/a> Steps of cleavage along the same cleavage direction[\/caption]\n\n&nbsp;\n\n[caption id=\"attachment_2831\" align=\"alignleft\" width=\"220\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.63_cleavage_in_Amphibole.jpg\"><img class=\"wp-image-2831\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.63_cleavage_in_Amphibole-295x300-1.jpg\" alt=\"Photomicrograph showing 120\/60 degree cleavage in amphibole\" width=\"220\" height=\"224\"><\/a> Photomicrograph showing 120\/60 degree cleavage within a grain of amphibole[\/caption]\n\n&nbsp;\n\nAs an identification property of [pb_glossary id=\"1765\"]minerals[\/pb_glossary], cleavage is usually given in terms of the quality of the cleavage (perfect, imperfect, or none), the number of cleavage surfaces, and the angles between the surfaces.\u00a0The most common number of cleavage plane directions in the common rock-forming [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are: one perfect cleavage (as in [pb_glossary id=\"966\"]mica[\/pb_glossary]), two cleavage planes (as in [pb_glossary id=\"968\"]feldspar[\/pb_glossary], [pb_glossary id=\"1790\"]pyroxene[\/pb_glossary], and [pb_glossary id=\"1791\"]amphibole[\/pb_glossary]), and three cleavage planes (as in [pb_glossary id=\"1922\"]halite[\/pb_glossary], [pb_glossary id=\"970\"]calcite[\/pb_glossary], and galena). One perfect cleavage (as in [pb_glossary id=\"966\"]mica[\/pb_glossary]) develops on the top and bottom of the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] specimen with many parallel cracks showing on the sides but no angle of intersection. Two cleavage planes intersect at an angle. Common cleavage angles are 60\u00b0, 75\u00b0, 90\u00b0, and 120\u00b0.\u00a0 [pb_glossary id=\"1791\"]Amphibole[\/pb_glossary] has two cleavage planes at\u00a060\u00b0 and\u00a0120\u00b0. Galena and [pb_glossary id=\"1922\"]halite[\/pb_glossary] have three cleavage planes at 90\u00b0 (cubic cleavage). [pb_glossary id=\"970\"]Calcite[\/pb_glossary] cleaves readily in three directions producing a cleavage figure called a rhomb that looks like a cube squashed over toward one corner giving rise to the approximately 75\u00b0 cleavage angles. [pb_glossary id=\"1790\"]Pyroxene[\/pb_glossary] has an imperfect cleavage with two planes at 90\u00b0.\n\n<strong>Cleavages on common rock-forming [pb_glossary id=\"1765\"]minerals[\/pb_glossary]<\/strong>\n<ul>\n \t<li>[pb_glossary id=\"967\"]Quartz[\/pb_glossary]\u2014none ([pb_glossary id=\"987\"]conchoidal[\/pb_glossary] [pb_glossary id=\"986\"]fracture[\/pb_glossary])<\/li>\n \t<li>[pb_glossary id=\"1789\"]Olivine[\/pb_glossary]\u2014none ([pb_glossary id=\"987\"]conchoidal[\/pb_glossary] [pb_glossary id=\"986\"]fracture[\/pb_glossary])<\/li>\n \t<li>[pb_glossary id=\"966\"]Mica[\/pb_glossary]\u20141 perfect<\/li>\n \t<li>[pb_glossary id=\"968\"]Feldspar[\/pb_glossary]\u20142 perfect at 90\u00b0<\/li>\n \t<li>[pb_glossary id=\"1790\"]Pyroxene[\/pb_glossary]\u20142 imperfect at 90\u00b0<\/li>\n \t<li>[pb_glossary id=\"1791\"]Amphibole[\/pb_glossary]\u20142 perfect at 60\u00b0\/120\u00b0<\/li>\n \t<li>[pb_glossary id=\"970\"]Calcite[\/pb_glossary]\u20143 perfect at approximately 75\u00b0<\/li>\n \t<li>[pb_glossary id=\"1922\"]Halite[\/pb_glossary], galena, pyrite\u20143 perfect at 90\u00b0<\/li>\n<\/ul>\n<h3><b>3.5.6 Special Properties <\/b><\/h3>\n[caption id=\"attachment_2832\" align=\"alignleft\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ulexit_Fernsehstein.jpg\"><img class=\"size-thumbnail wp-image-2832\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ulexit_Fernsehstein-150x150-1.jpg\" alt=\"The words on the page are projected upwards onto the mineral\" width=\"150\" height=\"150\"><\/a> A demonstration of ulexite's image projection[\/caption]\n\n<span style=\"font-weight: 400\">Special properties are unique and identifiable characteristics used to identify [pb_glossary id=\"1765\"]minerals[\/pb_glossary] or that allow some [pb_glossary id=\"1765\"]minerals[\/pb_glossary] to be used for special purposes.\u00a0<\/span>Ulexite has a fiber-optic property that can project images through the crystal like a high-definition television screen (see figure). A simple identifying special property is taste, such as the salty flavor of [pb_glossary id=\"1922\"]halite[\/pb_glossary] or common table salt (NaCl). Sylvite is potassium chloride (KCl) and has a more bitter taste.\n\n[caption id=\"attachment_2833\" align=\"alignright\" width=\"225\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Latrobe_gold_nugget_Natural_History_Museum.jpg\"><img class=\"size-medium wp-image-2833\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Latrobe_gold_nugget_Natural_History_Museum-225x300-1.jpg\" alt=\"The nugget is gold\" width=\"225\" height=\"300\"><\/a> Native gold has one of the highest specific gravities.[\/caption]\n\n&nbsp;\n\nAnother property geologists may use to identify [pb_glossary id=\"1765\"]minerals[\/pb_glossary] is a property related to density called <strong>[pb_glossary id=\"989\"]specific gravity[\/pb_glossary]<\/strong>. [pb_glossary id=\"989\"]Specific gravity[\/pb_glossary] measures the weight of a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] specimen relative to the weight of an equal volume of water. The value is expressed as a ratio between the [pb_glossary id=\"1765\"]mineral[\/pb_glossary] and water weights. To measure [pb_glossary id=\"989\"]specific gravity[\/pb_glossary], a [pb_glossary id=\"1765\"]mineral[\/pb_glossary] specimen is first weighed in grams then submerged in a graduated cylinder filled with pure water at room [pb_glossary id=\"1767\"]temperature[\/pb_glossary]. The rise in water level is noted using the cylinder\u2019s graduated scale. Since the weight of water at room [pb_glossary id=\"1767\"]temperature[\/pb_glossary] is 1 gram per cubic centimeter, the ratio of the two weight numbers gives the [pb_glossary id=\"989\"]specific gravity[\/pb_glossary]. [pb_glossary id=\"989\"]Specific gravity[\/pb_glossary] is easy to measure in the laboratory but is less useful for [pb_glossary id=\"1765\"]mineral[\/pb_glossary] identification in the field than other more easily observed properties, except in a few rare cases such as the very dense galena or [pb_glossary id=\"976\"]native[\/pb_glossary] gold. The high density of these [pb_glossary id=\"1765\"]minerals[\/pb_glossary] gives rise to a [pb_glossary id=\"1725\"]qualitative[\/pb_glossary] property called \u201cheft.\u201d Experienced geologists can roughly assess [pb_glossary id=\"989\"]specific gravity[\/pb_glossary] by heft, a [pb_glossary id=\"1723\"]subjective[\/pb_glossary] quality of how heavy the specimen feels in one\u2019s hand relative to its size.\n\nA simple test for identifying [pb_glossary id=\"970\"]calcite[\/pb_glossary] and dolomite is to drop a bit of dilute hydrochloric acid (10-15% HCl) on the specimen. If the acid drop effervesces or fizzes on the surface of the rock, the specimen is [pb_glossary id=\"970\"]calcite[\/pb_glossary]. If it does not, the specimen is scratched to produce a small amount of powder and test with acid again. If the acid drop fizzes slowly on the powdered [pb_glossary id=\"1765\"]mineral[\/pb_glossary], the specimen is dolomite. The difference between these two [pb_glossary id=\"1765\"]minerals[\/pb_glossary] can be seen in the video. Geologists who work with [pb_glossary id=\"969\"]carbonate[\/pb_glossary] rocks carry a small dropper bottle of dilute HCl in their field kit. Vinegar, which contains acetic acid, can be used for this test and is used to distinguish non-[pb_glossary id=\"970\"]calcite[\/pb_glossary] [pb_glossary id=\"1228\"]fossils[\/pb_glossary] from [pb_glossary id=\"1929\"]limestone[\/pb_glossary]. While acidic, vinegar produces less of a fizzing reaction because acetic acid is a weaker acid.\n\n[embed]https:\/\/www.youtube.com\/embed\/DX6ZMPbA09U[\/embed]\n\n[caption id=\"attachment_3750\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Calcite-and-Dolomite-YouTube-QR-Code.png\"><img class=\"size-thumbnail wp-image-228\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access this YouTube video via this QR Code.[\/caption]\n\n[caption id=\"attachment_2834\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Magnetite_Lodestone.jpg\"><img class=\"size-medium wp-image-2834\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Magnetite_Lodestone-300x200-1.jpg\" alt=\"The paperclip is sticking up into the air.\" width=\"300\" height=\"200\"><\/a> Paperclips attach to lodestone (magnetite).[\/caption]\n\nSome iron-[pb_glossary id=\"971\"]oxide[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are magnetic and are attracted to magnets. A common name for a naturally magnetic iron [pb_glossary id=\"971\"]oxide[\/pb_glossary] is <strong>lodestone<\/strong>. Others include magnetite (Fe3O<sub>4<\/sub>) and ilmenite (FeTiO<sub>3<\/sub>). Magnetite is strongly attracted to magnets and can be magnetized. Ilmenite and some types of hematite are weakly magnetic.\n\n[caption id=\"attachment_2825\" align=\"alignright\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.65_Striations_in_plagioclase.jpg\"><img class=\"wp-image-2825 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.65_Striations_in_plagioclase-300x242-1.jpg\" alt=\"Striations or parallel dark lines on one cleavage surface on plagioclase feldspar\" width=\"300\" height=\"242\"><\/a> Iridescence on plagioclase; also showing striations on the cleavage surface[\/caption]\n\n&nbsp;\n\n<span style=\"font-weight: 400\">Some [pb_glossary id=\"1765\"]minerals[\/pb_glossary] and mineraloids scatter light via a phenomenon called <strong>iridescence<\/strong>. This property occurs in labradorite (a variety of [pb_glossary id=\"968\"]plagioclase[\/pb_glossary]) and opal. It is also seen in biologically created substances like pearls and seashells. Cut diamonds show iridescence and the jeweler\u2019s diamond cut is designed to maximize this property.<\/span>\n\n[caption id=\"attachment_2835\" align=\"alignleft\" width=\"300\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.66_exsolution-_lamellae_perthitic_feldspar_Dan_Patch_SD.jpg\"><img class=\"size-medium wp-image-2835\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.66_exsolution-_lamellae_perthitic_feldspar_Dan_Patch_SD-300x217-1.jpg\" alt=\"Image showing exsolution lamellae in potassium feldspar. These are separations of sodium feldspar from potassium feldspar within the crystal, not striations.\" width=\"300\" height=\"217\"><\/a> Exsolution lamellae within potassium feldspar[\/caption]\n\n<strong>Striations<\/strong> on [pb_glossary id=\"1765\"]mineral[\/pb_glossary] cleavage faces are an optical property that can be used to separate [pb_glossary id=\"968\"]plagioclase[\/pb_glossary] [pb_glossary id=\"968\"]feldspar[\/pb_glossary] from potassium [pb_glossary id=\"968\"]feldspar[\/pb_glossary] ([pb_glossary id=\"968\"]K-spar[\/pb_glossary]). A process called twinning creates parallel zones in the crystal that are repeating mirror images. The actual cleavage angle in [pb_glossary id=\"968\"]plagioclase[\/pb_glossary] is slightly different than 90<sup>o<\/sup> and the alternating mirror images in these twinned zones produce a series of parallel lines on one of [pb_glossary id=\"968\"]plagioclase[\/pb_glossary]\u2019s two cleavage faces. Light reflects off these twinned lines at slightly different angles which then appear as light and dark lines called striations on the cleavage surface.\u00a0Potassium [pb_glossary id=\"968\"]feldspar[\/pb_glossary] does not exhibit twinning or striations but may show linear features called <strong>exsolution lamellae<\/strong>, also known as perthitic [pb_glossary id=\"2003\"]lineation[\/pb_glossary] or simply perthite. Because sodium and potassium do not fit into the same [pb_glossary id=\"968\"]feldspar[\/pb_glossary] crystal structure, the lines are created by small amounts of sodium [pb_glossary id=\"968\"]feldspar[\/pb_glossary] (albite) separating from the dominant potassium [pb_glossary id=\"968\"]feldspar[\/pb_glossary] ([pb_glossary id=\"968\"]K-spar[\/pb_glossary]) within the crystal structure. The two different [pb_glossary id=\"968\"]feldspars[\/pb_glossary] crystallize out into roughly parallel zones within the crystal, which are seen as these linear markings.\n\n[caption id=\"attachment_2793\" align=\"alignright\" width=\"244\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.35_FluoriteUV-scaled.jpg\"><img class=\"size-medium wp-image-2793\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.35_FluoriteUV-244x300-1.jpg\" alt=\"Purplish crystals of fluorite. The second image shows the deep blue fluorescence of fluorite under ultraviolet light.\" width=\"244\" height=\"300\"><\/a> Fluorite. B shows fluorescence of fluorite under UV light[\/caption]\n\nOne of the most interesting special [pb_glossary id=\"1765\"]mineral[\/pb_glossary] properties is <strong>fluorescence<\/strong>. Certain [pb_glossary id=\"1765\"]minerals[\/pb_glossary], or \u00a0trace [pb_glossary id=\"1778\"]elements[\/pb_glossary] within them, give off visible light when exposed to ultraviolet radiation or black light. Many [pb_glossary id=\"1765\"]mineral[\/pb_glossary] exhibits have a fluorescence room equipped with black lights so this property can be observed. An even rarer optical property is phosphorescence. <strong>Phosphorescent<\/strong> [pb_glossary id=\"1765\"]minerals[\/pb_glossary] absorb light and then slowly release it, much like a glow-in-the-dark sticker.\n\n&nbsp;\n\n&nbsp;\n<h3><\/h3>\n<h3><\/h3>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n[h5p id=\"21\"]\n\n[caption id=\"attachment_3749\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.5-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-231\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the quiz for section 3.5 via this QR Code.[\/caption]\n<h2><span style=\"font-size: 18pt\"><strong>Summary<\/strong><\/span><\/h2>\n[pb_glossary id=\"1765\"]Minerals[\/pb_glossary] are the building blocks of rocks and essential to understanding geology. [pb_glossary id=\"1765\"]Mineral[\/pb_glossary] properties are determined by their atomic [pb_glossary id=\"1781\"]bonds[\/pb_glossary]. Most [pb_glossary id=\"1765\"]minerals[\/pb_glossary] begin in a fluid, and either crystallize out of cooling [pb_glossary id=\"1750\"]magma[\/pb_glossary] or [pb_glossary id=\"1785\"]precipitate[\/pb_glossary] as ions and molecules out of a [pb_glossary id=\"1784\"]saturated[\/pb_glossary] [pb_glossary id=\"1783\"]solution[\/pb_glossary]. The [pb_glossary id=\"1787\"]silicates[\/pb_glossary] are largest group of [pb_glossary id=\"1765\"]minerals[\/pb_glossary] on Earth, by number of varieties and relative quantity, making up a large portion of the [pb_glossary id=\"1658\"]crust[\/pb_glossary] and [pb_glossary id=\"1664\"]mantle[\/pb_glossary]. Based on the [pb_glossary id=\"1788\"]silicon-oxygen tetrahedra[\/pb_glossary], the crystal structure of [pb_glossary id=\"1787\"]silicates[\/pb_glossary] reflects the fact that silicon and oxygen are the top two of Earth\u2019s most abundant [pb_glossary id=\"1778\"]elements[\/pb_glossary]. Non-[pb_glossary id=\"1787\"]silicate[\/pb_glossary] [pb_glossary id=\"1765\"]minerals[\/pb_glossary] are also economically important, and providing many types of construction and manufacturing materials. [pb_glossary id=\"1765\"]Minerals[\/pb_glossary] are identified by their unique physical properties, including [pb_glossary id=\"977\"]luster[\/pb_glossary], color, [pb_glossary id=\"978\"]streak[\/pb_glossary], [pb_glossary id=\"979\"]hardness[\/pb_glossary], [pb_glossary id=\"980\"]crystal habit[\/pb_glossary], [pb_glossary id=\"986\"]fracture[\/pb_glossary], cleavage, and special properties.\n<h3>Take this quiz to check your comprehension of this Chapter.<\/h3>\n[h5p id=\"22\"]\n\n[caption id=\"attachment_3748\" align=\"aligncenter\" width=\"150\"]<a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ch.3-Review-QR-Code.png\"><img class=\"size-thumbnail wp-image-232\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a> If you are using the printed version of this OER, access the review quiz for Chapter 3 via this QR Code.[\/caption]\n<h2><b>References<\/b><\/h2>\n<div class=\"csl-bib-body\">\n<ol>\n \t<li class=\"csl-entry\">Clarke, F.W.H.S.W., 1927, The [pb_glossary id=\"1909\"]Composition[\/pb_glossary] of the Earth\u2019s [pb_glossary id=\"1658\"]Crust[\/pb_glossary]: Professional Paper, United States Geological Survey, Professional Paper.<\/li>\n \t<li class=\"csl-entry\">Gordon, L.M., and Joester, D., 2011, Nanoscale chemical [pb_glossary id=\"2174\"]tomography[\/pb_glossary] of buried organic-inorganic interfaces in the chiton tooth: Nature, v. 469, no. 7329, p. 194\u2013197.<\/li>\n \t<li class=\"csl-entry\">Hans Wedepohl, K., 1995, The [pb_glossary id=\"1909\"]composition[\/pb_glossary] of the [pb_glossary id=\"1653\"]continental crust[\/pb_glossary]: Geochim. Cosmochim. Acta, v. 59, no. 7, p. 1217\u20131232.<\/li>\n \t<li class=\"csl-entry\">Lambeck, K., 1986, Planetary evolution: [pb_glossary id=\"1926\"]banded iron[\/pb_glossary] [pb_glossary id=\"2038\"]formations[\/pb_glossary]: v. 320, no. 6063, p. 574\u2013574.<\/li>\n \t<li class=\"csl-entry\">[pb_glossary id=\"2423\"]metallic[\/pb_glossary] [pb_glossary id=\"1781\"]bond[\/pb_glossary] | chemistry.<\/li>\n \t<li class=\"csl-entry\">Scerri, E.R., 2007, The Periodic Table: Its Story and Its Significance: Oxford University Press, USA.<\/li>\n \t<li class=\"csl-entry\">Thomson, J.J., 1897, XL. Cathode Rays: Philosophical Magazine Series 5, v. 44, no. 269, p. 293\u2013316.<\/li>\n \t<li class=\"csl-entry\">Trenn, T.J., Geiger, H., Marsden, E., and Rutherford, E., 1974, The Geiger-Marsden Scattering Results and Rutherford\u2019s Atom, July 1912 to July 1913: The Shifting Significance of Scientific Evidence: Isis, v. 65, no. 1, p. 74\u201382.<\/li>\n<\/ol>\n<\/div>\n<span style=\"font-weight: 400\">\u00a0<\/span>\n\n&nbsp;\n\n&nbsp;","rendered":"<figure id=\"attachment_2752\" aria-describedby=\"caption-attachment-2752\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Cristales_cueva_de_Naica.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2752 size-large\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/Cristales_cueva_de_Naica-1024x683-1.jpg\" alt=\"The crystals are huge!\" width=\"1024\" height=\"683\" \/><\/a><figcaption id=\"caption-attachment-2752\" class=\"wp-caption-text\">These selenite (gypsum) crystals, found in The Cave of the Crystals in Naica, Mexico, has some of the largest minerals ever found. The largest crystal found here is 39 feet (12 meters) and 55 tones.<\/figcaption><\/figure>\n<h1>3 Minerals<\/h1>\n<p><strong>KEY<\/strong><b> CONCEPTS<\/b><\/p>\n<p><b>At the end of this chapter, students should be able to:<\/b><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Define <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Describe the basic structure of the atom.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Derive basic atomic information from the Periodic Table of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">Elements<\/a>.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Describe chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonding<\/a> related to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Describe the main ways <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> form.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Describe the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silicon-oxygen tetrahedron<\/a> and how it forms common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">List common non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_974\">sulfate<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> groups.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> using physical properties and identification tables. <\/span><\/li>\n<\/ul>\n<p>The term \u201c<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u201d as used in nutrition labels and pharmaceutical products is not the same as a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> in a geological sense. In geology, the classic definition of a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a><\/strong> is: 1) naturally occurring, 2) inorganic, 3) solid at room <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a>, 4) regular crystal structure, and 5) defined chemical composition. Some natural substances technically should not be considered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, but are included by exception. For example, water and mercury are liquid at room <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a>. Both are considered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> because they were classified before the room-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> rule was accepted as part of the definition. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">Calcite<\/a> is quite often formed by organic processes, but is considered a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> because it is widely found and geologically important. Because of these discrepancies, the International Mineralogical Association in 1985 amended the definition to: \u201cA <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> is an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> or chemical compound that is normally crystalline and that has been formed as a result of geological processes.\u201d This means that the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> in the shell of a clam is not considered a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>. But once that clam shell undergoes burial, diagenesis, or other geological processes, then the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> is considered a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>. Typically, substances like coal, pearl, opal, or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_999\">obsidian<\/a> that do not fit the definition of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> are called mineraloids.<\/p>\n<p>A <strong>rock<\/strong> is a substance that contains one or more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> or mineraloids. As is discussed in later chapters, there are three types of rocks composed of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> (rocks crystallizing from molten material), sedimentary (rocks composed of products of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_251\">mechanical weathering<\/a> (sand, gravel, etc.) and chemical weathering (things <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitated<\/a> from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a>), and metamorphic (rocks produced by alteration of other rocks by heat and pressure.<\/p>\n<h2><span style=\"font-weight: 400\">3.1 Chemistry of Minerals<\/span><\/h2>\n<p>Rocks are composed of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that have a specific chemical composition.\u00a0 To understand <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> chemistry, it is essential to examine the fundamental unit of all matter, the atom.<\/p>\n<h3><b>3.1.1 The Atom<\/b><\/h3>\n<figure id=\"attachment_2753\" aria-describedby=\"caption-attachment-2753\" style=\"width: 283px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.1-Electron_cloud_model_of_atom.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2753\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/03.1-Electron_cloud_model_of_atom-283x300-1.jpg\" alt=\"Image of atom with defined nucleus and electrons surrounding it in a cloud with concentrations of electrons in energy shells\" width=\"283\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2753\" class=\"wp-caption-text\">Electron cloud model of the atom<\/figcaption><\/figure>\n<p>Matter is made of atoms. Atoms consists of subatomic particles\u2014<strong>protons<\/strong>, <strong>neutrons<\/strong>, and <strong>electrons<\/strong>. A simple model of the atom has a central nucleus composed of protons, which have positive charges, and neutrons which have no charge. A cloud of negatively charged electrons surrounds the nucleus, the number of electrons equaling the number of protons thus balancing the positive charge of the protons for a neutral atom. Protons and neutrons each have a mass number of 1. The mass of an electron is less than\u00a01\/1000<sup>th<\/sup>\u00a0that of a proton or neutron, meaning most of the atom\u2019s mass is in the nucleus.<\/p>\n<h3><b>3.1.2 Periodic Table of the Elements<\/b><\/h3>\n<p>Matter is composed of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> which are atoms that have a specific number of protons in the nucleus. This number of protons is called the <strong>Atomic Number<\/strong> for the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>. For example, an oxygen atom has 8 protons and an iron atom has 26 protons. An <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> cannot be broken down chemically into a simpler form and retains unique chemical and physical properties. Each <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> behaves in a unique manner in nature. This uniqueness led scientists to develop a periodic table of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>, a tabular arrangement of all known <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> listed in order of their atomic number.<\/p>\n<figure id=\"attachment_2754\" aria-describedby=\"caption-attachment-2754\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Periodic_Table-02-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-large wp-image-2754\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/Periodic_Table-02-1024x795-1.jpg\" alt=\"The Periodic Table of the Elements showing all elements with their chemical symbols, atomic weight, and atomic number.\" width=\"1024\" height=\"795\" \/><\/a><figcaption id=\"caption-attachment-2754\" class=\"wp-caption-text\">The Periodic Table of the Elements<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">The first arrangement of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> into a periodic table was done by Dmitri Mendeleev in 1869 using the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> known at the time<\/span><span style=\"font-weight: 400\">. In the periodic table, each <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> has a chemical symbol, name, atomic number, and atomic mass. The chemical symbol is an abbreviation for the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>, often derived from a Latin or Greek name for the substance<\/span><span style=\"font-weight: 400\">. The atomic number is the number of protons in the nucleus. The atomic mass is the number of protons and neutrons in the nucleus, each with a mass number of one. Since the mass of electrons is so much less than the protons and neutrons, the atomic mass is effectively the number of protons plus neutrons. <\/span><\/p>\n<figure id=\"attachment_2755\" aria-describedby=\"caption-attachment-2755\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.3a_Formation_of_Carbon14_from_Nitrogen14.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2755\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/3.3a_Formation_of_Carbon14_from_Nitrogen14-300x123-1.jpg\" alt=\"\" width=\"300\" height=\"123\" \/><\/a><figcaption id=\"caption-attachment-2755\" class=\"wp-caption-text\">Formation of Carbon 14 from Nitrogen 14<\/figcaption><\/figure>\n<p>The atomic mass of natural <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> represents an average mass of the atoms comprising that substance in nature and is usually not a whole number as seen on the periodic table, meaning that an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> exists in nature with atoms having different numbers of neutrons. The differing number of neutrons affects the mass of an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> in nature and the atomic mass number represents this average. This gives rise to the concept of\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1779\">isotope<\/a><strong>.\u00a0<\/strong><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1779\">Isotopes<\/a> <\/strong>are forms of an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> with the same number of protons but different numbers of neutrons. There are usually several <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1779\">isotopes<\/a> for a particular <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>. For example, 98.9% of carbon atoms have 6 protons and 6 neutrons. This <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1779\">isotope<\/a> of carbon is called carbon-12 (<sup>12<\/sup>C). A few carbon atoms, carbon-13 (<sup>13<\/sup>C), have 6 protons and 7 neutrons. A trace amount of carbon atoms, carbon-14 (<sup>14<\/sup>C), has 6 protons and 8 neutrons.<\/p>\n<figure id=\"attachment_2756\" aria-describedby=\"caption-attachment-2756\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/elemental-composition-crust.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2756\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/elemental-composition-crust-300x277-1.jpg\" alt=\"Oxygen and silicon make up 3\/4ths of the chart.\" width=\"300\" height=\"277\" \/><\/a><figcaption id=\"caption-attachment-2756\" class=\"wp-caption-text\">Element abundance pie chart for Earth&rsquo;s crust by Callan Bentley.<\/figcaption><\/figure>\n<p>Among the 118 known <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>, the heaviest are fleeting human creations known only in high energy particle accelerators, and they decay rapidly. The heaviest naturally occurring <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> is uranium, atomic number 92. The eight most abundant elements in Earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental crust<\/a> are shown in Table 1<span style=\"font-weight: 400\">. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> are found in the most common rock forming <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<table style=\"height: 135px\">\n<tbody>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><b><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">Element<\/a><\/b><\/td>\n<td style=\"height: 15px;width: 134.797px\"><b>Symbol<\/b><\/td>\n<td style=\"height: 15px;width: 237.703px\"><b>Abundance %<\/b><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Oxygen<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">O<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">47%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Silicon<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Si<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">28%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Aluminum<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Al<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">8%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Iron<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Fe<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">5%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Calcium<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Ca<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">4%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Sodium<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\"><span style=\"font-weight: 400\">Na<\/span><\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">3%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Potassium<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\">K<\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">3%<\/span><\/td>\n<\/tr>\n<tr style=\"height: 15px\">\n<td style=\"height: 15px;width: 202.188px\"><span style=\"font-weight: 400\">Magnesium<\/span><\/td>\n<td style=\"height: 15px;width: 134.797px\">Mg<\/td>\n<td style=\"height: 15px;width: 237.703px\"><span style=\"font-weight: 400\">2%<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em style=\"font-size: 16px;font-weight: 400\">Table 1. Eight Most Abundant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">Elements<\/a> in the Earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">Continental Crust<\/a> % by weight (source:\u00a0<a href=\"https:\/\/pubs.usgs.gov\/circ\/1953\/0285\/report.pdf\">USGS<\/a>). All other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> are less than 1%.<\/em><\/p>\n<h3><b>3.1.3 Chemical Bonding<\/b><\/h3>\n<figure id=\"attachment_2757\" aria-describedby=\"caption-attachment-2757\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/H2O_2D_labelled.svg_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-145 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/H2O_2D_labelled.svg_-300x131.png\" alt=\"The hydrogen atoms are on one side, about 105\u00b0 apart.\" width=\"300\" height=\"131\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/H2O_2D_labelled.svg_-300x131.png 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/H2O_2D_labelled.svg_-768x336.png 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/H2O_2D_labelled.svg_-65x28.png 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/H2O_2D_labelled.svg_-225x98.png 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/H2O_2D_labelled.svg_-350x153.png 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/H2O_2D_labelled.svg_.png 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-2757\" class=\"wp-caption-text\">A model of a water molecule, showing the bonds between the hydrogen and oxygen.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Most substances on Earth are compounds containing multiple <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. Chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonding<\/a> describes how these atoms attach with each other to form compounds, such as sodium and chlorine combining to form NaCl, common table salt. Compounds that are held together by\u00a0<\/span>chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> are called molecules. Water is a compound of hydrogen and oxygen in which two hydrogen atoms are covalently <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> with one oxygen making the water molecule. The oxygen we breathe is formed when one oxygen atom covalently <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> with another oxygen atom to make the molecule O<sub>2<\/sub>. The subscript 2 in the chemical formula indicates the molecule contains two atoms of oxygen.<\/p>\n<p>Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are also compounds of more than one <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>. The common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> has the chemical formula CaCO<sub>3<\/sub> indicating the molecule consists of one calcium, one carbon, and three oxygen atoms.\u00a0In <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a>, one carbon and three oxygen atoms are held together by covalent <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> to form a <strong>molecular ion<\/strong>, called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a>, which has a negative charge. Calcium as an <strong>ion<\/strong> has a positive charge of plus two. The two oppositely charged ions attract each other and combine to form the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a>, CaCO3. The name of the chemical compound is calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a>, where calcium is Ca and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> refers to the molecular ion CO<sub>3<\/sub><sup>-2<\/sup>.<\/p>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a> has the chemical formula (Mg,Fe)<sub>2<\/sub>SiO<sub>4<\/sub>, in which one silicon and four oxygen atoms are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> with two atoms of either magnesium or iron.\u00a0The comma between iron (Fe) and magnesium (Mg) indicates the two <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> can occupy the same location in the crystal structure and substitute for one another.<\/p>\n<h4><i><span style=\"font-weight: 400\">3.1.3.1 Valence and Charge<\/span><\/i><\/h4>\n<p><span style=\"font-weight: 400\">The electrons around the atom\u2019s nucleus are located in shells representing different energy levels. The outermost shell is called the <strong>valence shell<\/strong>. Electrons in the valence shell are involved in chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonding<\/a>. In 1913, Niels Bohr proposed a simple model of the atom that states atoms are more stable when their outermost shell is full<\/span><span style=\"font-weight: 400\">. Atoms of most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> thus tend to gain or lose electrons so the outermost or valence shell is full. In Bohr\u2019s model, the innermost shell can have a maximum of two electrons and the second and third shells can have a maximum of eight electrons. <\/span>When the innermost shell is the valence shell, as in the case of hydrogen and helium, it obeys the octet rule when it is full with two electrons. For <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> in higher rows, the octet rule of eight electrons in the valence shell applies.<\/p>\n<figure id=\"attachment_2758\" aria-describedby=\"caption-attachment-2758\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.4_Carbon_dioxide_3D_ball.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2758 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.4_Carbon_dioxide_3D_ball-300x213-1.png\" alt=\"Carbon dioxide molecule with a carbon ion in the center and two oxygen ions on either side, each sharing two electrons with the carbon.\" width=\"300\" height=\"213\" \/><\/a><figcaption id=\"caption-attachment-2758\" class=\"wp-caption-text\">The carbon dioxide molecule. Since Oxygen is -2 and Carbon is +4, the two oxygens bond to the carbon to form a neutral molecule.<\/figcaption><\/figure>\n<p>The rows in the periodic table present the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> in order of atomic number and the columns organize <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> with similar characteristics, such as the same number of electrons in their valence shells. Columns are often labeled from left to right with Roman numerals I to VIII, and Arabic numerals 1 through 18. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> in columns I and II have 1 and 2 electrons in their respective valence shells and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> in columns VI and VII have 6 and 7 electrons in their respective valence shells.<\/p>\n<p><span style=\"font-weight: 400\">In row 3 and column I, sodium (Na) has 11 protons in the nucleus and 11 electrons in three shells\u20142 electrons in the inner shell, 8 electrons in the second shell, and 1 electron in the valence shell. To maintain a full outer shell of 8 electrons per the octet rule, sodium readily gives up that 1 electron so there are 10 total electrons. With 11 positively charged protons in the nucleus and 10 negatively charged electrons in two shells, sodium when forming chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> is an ion with an overall net charge of +1<\/span><span style=\"font-weight: 400\">.<\/span><\/p>\n<p><span style=\"font-weight: 400\">All <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> in column I have a single electron in their valence shell and a valence of 1.\u00a0<\/span>These other column I <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> also readily give up this single valence electron and thus become ions with a +1 charge. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">Elements<\/a> in column II readily give up 2 electrons and end up as ions with a charge of +2. Note that elements in columns I and II which readily give up their valence electrons, often form bonds with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> in columns VI and VII which readily take up these electrons. \u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">Elements<\/a> in columns 3 through 15 are usually involved in covalent <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonding<\/a>. The last column 18 (VIII) contains the <strong>noble gases<\/strong>. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> are chemically inert because the valence shell is already full with 8 electrons, so they do not gain or lose electrons. An example is the noble gas helium which has 2 valence electrons in the first shell. Its valence shell is therefore full. All <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> in column VIII possess full valence shells and do not form <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> with other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>.<\/p>\n<p><span style=\"font-weight: 400\">As seen above, an atom with a net positive or negative charge as a result of gaining or losing electrons is called an <strong>ion<\/strong>. In general the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> on the left side of the table lose electrons and become positive ions, called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1780\">cations<\/a> because they are attracted to the cathode in an electrical device. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> on the right side tend to gain electrons. These are called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1782\">anions<\/a> because they are attracted to the anode in an electrical device. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> in the center of the periodic table, columns 3 through 15, do not consistently follow the octet rule. These are called transition <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. A common example is iron, which has a +2 or +3 charge depending on the oxidation state of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>. Oxidized Fe<sup>+3<\/sup> carries a +3 charge and reduced Fe<sup>+2<\/sup> is +2. These two different oxidation states of iron often impart dramatic colors to rocks containing their <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u2014the oxidized form producing red colors and the reduced form producing green.<\/span><\/p>\n<h4><i><span style=\"font-weight: 400\">3.1.3.2\u00a0<\/span><\/i><i><span style=\"font-weight: 400\">Ionic Bonding<\/span><\/i><\/h4>\n<figure id=\"attachment_2759\" aria-describedby=\"caption-attachment-2759\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03-Sodium-chloride-3D-ionic.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2759\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03-Sodium-chloride-3D-ionic-300x284-1.png\" alt=\"Image of crystal model of halite with ions of sodium and chlorine arranged in a cubic structure.\" width=\"300\" height=\"284\" \/><\/a><figcaption id=\"caption-attachment-2759\" class=\"wp-caption-text\">Cubic arrangement of Na and Cl in Halite<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Ionic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a>, also called electron-transfer <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a>, are formed by the electrostatic attraction between atoms having opposite charges. Atoms of two opposite charges attract each other electrostatically and form an <strong>ionic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a><\/strong> in which the positive ion transfers its electron (or electrons) to the negative ion which takes them up. Through this transfer both atoms thus achieve a full valence shell.\u00a0<\/span>For example one atom of sodium (Na<sup>+1<\/sup>) and one atom of chlorine (Cl<sup>-1<\/sup>) form an ionic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a> to make the compound sodium chloride (NaCl). This is also known as the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> halite or common table salt. Another example is calcium (Ca<sup>+2<\/sup>) and chlorine (Cl<sup>-1<\/sup>) combining to make the compound calcium chloride (CaCl<sub>2<\/sub>). The subscript 2 indicates two atoms of chlorine are ionically <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> to one atom of calcium.<\/p>\n<h4><i><span style=\"font-weight: 400\">3.1.3.3\u00a0<\/span><\/i><i><span style=\"font-weight: 400\">Covalent <\/span><\/i><i><span style=\"font-weight: 400\">Bonding<\/span><\/i><\/h4>\n<figure id=\"attachment_2760\" aria-describedby=\"caption-attachment-2760\" style=\"width: 249px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Covalent.svg_.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2760\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Covalent.svg_-249x300-1.png\" alt=\"Each atom is sharing electrons.\" width=\"249\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2760\" class=\"wp-caption-text\">Methane molecule<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Ionic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> are usually formed between a <strong>metal<\/strong> and a <strong>nonmetal<\/strong>. Another type, called a covalent or electron-sharing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a>, commonly occurs between nonmetals. Covalent <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> share electrons between ions to complete their valence shells. For example, oxygen (atomic number 8) has 8 electrons\u20142 in the inner shell and 6 in the valence shell. Gases like oxygen often form diatomic molecules by sharing valence electrons. In the case of oxygen, two atoms attach to each other and share 2 electrons to fill their valence shells to become the common oxygen molecule we breathe (O<sub>2<\/sub>). Methane (CH<sub>4<\/sub>) is another covalently <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> gas. The carbon atom needs 4 electrons and each hydrogen needs 1. Each hydrogen shares its electron with the carbon to form a molecule as shown in the figure.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-17\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-17\" class=\"h5p-iframe\" data-content-id=\"17\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"3.1 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3754\" aria-describedby=\"caption-attachment-3754\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.1-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-149\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.1-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3754\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 3.1 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-size: 28px\">3.2 Formation of Minerals<\/span><\/h2>\n<p><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> form when atoms <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a> together in a crystalline arrangement. Three main ways this occurs in nature are: 1) <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> directly from an aqueous (water) <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a> with a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> change, 2) <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1752\">crystallization<\/a> from a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> with a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> change, and 3) biological <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> by the action of organisms. <\/span><\/p>\n<h3><b> 3.2.1 Precipitation from aqueous solution<\/b><\/h3>\n<figure id=\"attachment_2761\" aria-describedby=\"caption-attachment-2761\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.5_Hard_Water_Calcification.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2761\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.5_Hard_Water_Calcification-300x200-1.jpg\" alt=\"Encrusted calcium carbonate (lime) deposits on faucent\" width=\"300\" height=\"200\" \/><\/a><figcaption id=\"caption-attachment-2761\" class=\"wp-caption-text\">Calcium carbonate deposits from hard water<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">Solutions<\/a> consist of ions or molecules, known as solutes, dissolved in a medium or solvent. In nature this solvent is usually water. Many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> can be dissolved in water, such as halite or table salt, which has the composition sodium chloride, NaCl. The Na<sup>+1<\/sup> and Cl<sup>-1<\/sup> ions separate and disperse into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a>.<\/p>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">Precipitation<\/a><\/strong> is the reverse process, in which ions in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a> come together to form solid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">Precipitation<\/a> is dependent on the concentration of ions in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a> and other factors such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> and pressure. The point at which a solvent cannot hold any more solute is called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1784\">saturation<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">Precipitation<\/a> can occur when the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a> falls, when the solute evaporates, or with changing chemical conditions in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a>. An example of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> in our homes is when water evaporates and leaves behind a rind of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> on faucets, shower heads, and drinking glasses.<\/p>\n<p>In nature, changes in environmental conditions may cause the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> dissolved in water to form <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> and grow into crystals or cement grains of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediment<\/a> together. In Utah, deposits of tufa formed from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>-rich springs that emerged into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_747\">ice age<\/a> Lake Bonneville. Now exposed in dry valleys, this porous tufa was a natural insulation used by pioneers to build their homes with a natural protection against summer heat and winter cold. The travertine terraces at Mammoth Hot Springs in Yellowstone Park are another example formed by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> at the edges of the shallow spring-fed ponds.<\/p>\n<figure id=\"attachment_2762\" aria-describedby=\"caption-attachment-2762\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.6_1200px-Bonneville_Salt_Flats.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2762\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.6_1200px-Bonneville_Salt_Flats-300x197-1.jpg\" alt=\"The Bonneville Salt Flats of Utah\" width=\"300\" height=\"197\" \/><\/a><figcaption id=\"caption-attachment-2762\" class=\"wp-caption-text\">The Bonneville Salt Flats of Utah<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\">Another example of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> occurs in the Great Salt Lake, Utah, where the concentration of sodium chloride and other salts is nearly eight times greater than in the world\u2019s oceans <\/span><span style=\"font-weight: 400\">[zotpressInText item=\u00a0\u00bb{DU5CMSHJ}\u00a0\u00bb format=\u00a0\u00bb%num%\u00a0\u00bb brackets=\u00a0\u00bbyes\u00a0\u00bb]<\/span><span style=\"font-weight: 400\">.\u00a0<\/span>Streams carry salt ions into the lake from the surrounding mountains. With no other outlet, the water in the lake evaporates and the concentration of salt increases until <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1784\">saturation<\/a> is reached and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitate<\/a> out as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>. Similar salt deposits include halite and other precipitates, and occur in other lakes like Mono Lake in California and the Dead Sea.<\/p>\n<h3><b>3.2.2 Crystallization from Magma<\/b><\/h3>\n<figure id=\"attachment_2763\" aria-describedby=\"caption-attachment-2763\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.5a_Pahoehoe_toe.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2763\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.5a_Pahoehoe_toe-300x188-1.jpg\" alt=\"A lava flow\" width=\"300\" height=\"188\" \/><\/a><figcaption id=\"caption-attachment-2763\" class=\"wp-caption-text\">Lava, magma at the earth\u2019s surface<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Heat is energy that causes atoms in substances to vibrate. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">Temperature<\/a> is a measure of the intensity of the vibration. If the vibrations are violent enough, chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> are broken and the crystals melt releasing the ions into the melt. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">Magma<\/a> is molten rock with freely moving ions. When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> is emplaced at depth or extruded onto the surface (then called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a>), it starts to cool and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> crystals can form.<\/p>\n<h3><b>3.2.3 Precipitation by Organisms<\/b><\/h3>\n<figure id=\"attachment_2764\" aria-describedby=\"caption-attachment-2764\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.8_Ammonite_Asteroceras.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2764\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.8_Ammonite_Asteroceras.jpg\" alt=\"Shell of an ammonite, an extinct cephalopod, with a spiral shell in a plane.\" width=\"300\" height=\"225\" \/><\/a><figcaption id=\"caption-attachment-2764\" class=\"wp-caption-text\">Ammonite shell made of calcium carbonate<\/figcaption><\/figure>\n<p><span style=\"font-size: 1em\">Many organisms build bones, shells, and body coverings by extracting ions from water and precipitating <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> biologically. The most common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitated<\/a> by organisms is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a>, or calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> (CaCO3). <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">Calcite<\/a> is often <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitated<\/a> by organisms as a polymorph called aragonite. <\/span><strong style=\"font-size: 1em\">Polymorphs<\/strong><span style=\"font-size: 1em\"> are crystals with the same chemical formula but different crystal structures. Marine invertebrates such as corals and clams <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitate<\/a> aragonite or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> for their shells and structures. Upon death, their hard parts accumulate on the ocean floor as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>, and eventually may become the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1761\">sedimentary rock<\/a> limestone. Though limestone can form inorganically, the vast majority is formed by this biological process. Another example is marine organisms called radiolaria, which are zooplankton that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitate<\/a> silica for their microscopic external shells. When the organisms die, the shells accumulate on the ocean floor and can form the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1761\">sedimentary rock<\/a> chert. An example of biologic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1274\">vertebrate<\/a> world is bone, which is composed mostly of a type of apatite, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_975\">phosphate<\/a> group. The apatite found in bones contains calcium and water in its structure and is called hydroxycarbonate apatite, Ca<\/span><sub>5<\/sub><span style=\"font-size: 1em\">(PO<\/span><sub>4<\/sub><span style=\"font-size: 1em\">)<\/span><sub>3<\/sub><span style=\"font-size: 1em\">(OH).\u00a0 As mentioned above, such substances are not technically <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> until the organism dies and these hard parts become <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a>.<\/span><\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-18\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-18\" class=\"h5p-iframe\" data-content-id=\"18\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"3.2 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3753\" aria-describedby=\"caption-attachment-3753\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.2-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-154\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.2-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3753\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 3.2 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">3.3 Silicate Minerals<\/span><\/h2>\n<figure id=\"attachment_2765\" aria-describedby=\"caption-attachment-2765\" style=\"width: 256px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tetrahedron.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2765\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tetrahedron.gif\" alt=\"It is a pyramid shape with a triangular base\" width=\"256\" height=\"256\" \/><\/a><figcaption id=\"caption-attachment-2765\" class=\"wp-caption-text\">Rotating animation of a tetrahedra<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> are categorized based on their composition and structure. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">Silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are built around a molecular ion called the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silicon-oxygen tetrahedron<\/a><\/strong>. A tetrahedron has a pyramid-like shape with four sides and four corners.\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">Silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> form the largest group of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> on Earth, comprising the vast majority of the Earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>. Of the nearly four thousand known <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> on Earth, most are rare. There are only a few that make up most of the rocks likely to be encountered by surface dwelling creatures like us. These are generally called the <strong>rock-forming <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a><\/strong>.<\/p>\n<figure id=\"attachment_2766\" aria-describedby=\"caption-attachment-2766\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.10_Tetrahedron.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2766\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.10_Tetrahedron-300x300-1.jpg\" alt=\"Model of silicon-oxygen tetrahedron of ping pong balls with a tiny silicon ion in the space in the middle of the four large balls\" width=\"300\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2766\" class=\"wp-caption-text\">Ping pong ball model of tetrahedron: balls are oxygen, lead sinker in center is silicon<\/figcaption><\/figure>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silicon-oxygen tetrahedron<\/a> (SiO<sub>4<\/sub>) consists of a single silicon atom at the center and four oxygen atoms located at the four corners of the tetrahedron. Each oxygen ion has a -2 charge and the silicon ion has a +4 charge. The silicon ion shares one of its four valence electrons with each of the four oxygen ions in a covalent <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a> to create a symmetrical geometric four-sided pyramid figure. Only half of the oxygen\u2019s valence electrons are shared, giving the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silicon-oxygen tetrahedron<\/a> an ionic charge of -4. This <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silicon-oxygen tetrahedron<\/a> forms bonds with many other combinations of ions to form the large group of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/p>\n<figure id=\"attachment_2767\" aria-describedby=\"caption-attachment-2767\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.11_Tetrahedron_open.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2767\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.11_Tetrahedron_open-300x255-1.jpg\" alt=\"Top ball removed showing the tiny silicon ion in the center\" width=\"300\" height=\"255\" \/><\/a><figcaption id=\"caption-attachment-2767\" class=\"wp-caption-text\">The silicon ion in the center of the tetrahedron<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\">The silicon ion is much smaller than the oxygen ions (see the figures) and fits into a small space in the center of the four large oxygen ions, seen if the top ball is removed (as shown in the figure to the right). <\/span><span style=\"font-weight: 400\">Because only one of the valence electrons of the corner oxygens is shared, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silicon-oxygen tetrahedron<\/a> has chemically active corners available to form <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> with other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silica tetrahedra<\/a> or other positively charged ions such as Al<\/span><sub><span style=\"font-weight: 400\">+3<\/span><\/sub><span style=\"font-weight: 400\">, Fe<\/span><sub><span style=\"font-weight: 400\">+2,+3<\/span><\/sub><span style=\"font-weight: 400\">, Mg<\/span><sub><span style=\"font-weight: 400\">+2<\/span><\/sub><span style=\"font-weight: 400\">, K<\/span><sub><span style=\"font-weight: 400\">+1<\/span><\/sub><span style=\"font-weight: 400\">, Na<\/span><sub><span style=\"font-weight: 400\">+1<\/span><\/sub><span style=\"font-weight: 400\">, and Ca<\/span><sub><span style=\"font-weight: 400\">+2<\/span><\/sub><span style=\"font-weight: 400\">. Depending on many factors, such as the original <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> chemistry, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silica-oxygen tetrahedra<\/a> can combine with other tetrahedra in several different configurations. For example, tetrahedra can be isolated, attached in chains, sheets, or three dimensional structures. These combinations and others create the chemical structure in which positively charged ions can be inserted for unique chemical compositions forming <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> groups. \u00a0\u00a0<\/span><\/p>\n<h3><b>3.3.1 The dark ferromagnesian silicates<\/b><\/h3>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2768\" aria-describedby=\"caption-attachment-2768\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.12_Peridot_in_basalt.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2768\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.12_Peridot_in_basalt-300x225-1.jpg\" alt=\"Many small crystall of the green mineral olivine in a mass of basalt\" width=\"300\" height=\"225\" \/><\/a><figcaption id=\"caption-attachment-2768\" class=\"wp-caption-text\">Olivine crystals in basalt<\/figcaption><\/figure>\n<p><span style=\"font-size: 14pt\"><b>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">Olivine<\/a> Family<\/b><\/span><\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">Olivine<\/a> is the primary <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> component in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> rock such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1666\">peridotite<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1013\">basalt<\/a>. It is characteristically green when not weathered. The chemical formula is (Fe,Mg)<sub>2<\/sub>SiO<sub>4<\/sub>. As previously described, the comma between iron (Fe) and magnesium (Mg) indicates these two <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> occur in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a>.\u00a0<span style=\"font-weight: 400\">Not to be confused with a liquid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a>, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a> occurs when two or more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> have similar properties and can freely substitute for each other in the same location in the crystal structure.<\/span><\/p>\n<figure id=\"attachment_2769\" aria-describedby=\"caption-attachment-2769\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.13_Atomic_structure_of_olivine_1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-2769\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.13_Atomic_structure_of_olivine_1.png\" alt=\"Tetrahedral structure of olivine showing the independent tetrahedra connected together by anions of iron and\/or magnesium.\" width=\"300\" height=\"258\" \/><\/a><figcaption id=\"caption-attachment-2769\" class=\"wp-caption-text\">Tetrahedral structure of olivine<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">Olivine<\/a> is referred to as a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> family because of the ability of iron and magnesium to substitute for each other. Iron and magnesium in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a> family indicates a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a> forming a compositional series within the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> group which can form crystals of all iron as one end member and all mixtures of iron and magnesium in between to all magnesium at the other end member. Different <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> names are applied to compositions between these end members.\u00a0 In the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a> series of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, the iron and magnesium ions in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a> are about the same size and charge, so either atom can fit into the same location in the growing crystals. Within the cooling <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> crystals continue to grow until they solidify into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous rock<\/a>. The relative amounts of iron and magnesium in the parent <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> determine which <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> in the series form. Other rarer <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> with similar properties to iron or magnesium, like manganese (Mn), can substitute into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a> crystalline structure in small amounts. Such ionic substitutions in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> crystals give rise to the great variety of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> and are often responsible for differences in color and other properties within a group or family of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">Olivine<\/a> has a pure iron end-member (called fayalite) and a pure magnesium end-member (called forsterite). Chemically, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a> is mostly silica, iron, and magnesium and therefore is grouped among the dark-colored <\/span>ferromagnesian<span style=\"font-weight: 400\"> (iron=ferro, magnesium=magnesian) or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">mafic<\/a><\/strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, a contraction of their chemical symbols Ma and Fe. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">Mafic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are also referred to as dark-colored ferromagnesian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. <em>Ferro<\/em> means iron and <em>magnesian<\/em> refers to magnesium. Ferromagnesian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a> tend to be more dense than non-ferromagnesian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a>. This difference in density ends up being important in controlling the behavior of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> rocks that are built from these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>: whether a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducts<\/a> or not is largely governed by the density of its rocks, which are in turn controlled by the density of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that comprise them.<\/span><\/p>\n<p>The crystal structure of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a> is built from independent <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silica tetrahedra<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals <\/a>with independent tetrahedral structures are called neosilicates (or orthosilicates). In addition to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a>, other common neosilicate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> include garnet, topaz, kyanite, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1227\">zircon<\/a>.<\/p>\n<p>Two other similar arrangements of tetrahedra are close in structure to the neosilicates and grade toward the next group of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, the pyroxenes. In a variation on independent tetrahedra called sorosilicates, there are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that share one oxygen between two tetrahedra, and include <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> like pistachio-green epidote, a gemstone. Another variation are the cyclosilicates, which as the name suggests, consist of tetrahedral rings, and include gemstones such as beryl, emerald, aquamarine, and tourmaline<\/p>\n<h3><b>3.3.2 Pyroxene Family<\/b><\/h3>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2770\" aria-describedby=\"caption-attachment-2770\" style=\"width: 300px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.14_Diopside-172005.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2770 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.14_Diopside-172005-300x231-1.jpg\" alt=\"Dark green crystals of diopside, a member of the pyroxene family\" width=\"300\" height=\"231\" \/><\/a><figcaption id=\"caption-attachment-2770\" class=\"wp-caption-text\">Crystals of diopside, a member of the pyroxene family<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2771\" aria-describedby=\"caption-attachment-2771\" style=\"width: 70px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.15_Pyroxen-chain.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2771\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.15_Pyroxen-chain.png\" alt=\"Single chain of tetrahedra in pyroxene, alternating with adjacent corner oxygens bonded. The outer corners are active to bond with other anions.\" width=\"70\" height=\"517\" \/><\/a><figcaption id=\"caption-attachment-2771\" class=\"wp-caption-text\">Single chain tetrahedral structure in pyroxene<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">Pyroxene<\/a> is another family of dark ferromagnesian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, typically black or dark green in color. Members of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a> family have a complex chemical composition that includes iron, magnesium, aluminum, and other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> to polymerized <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silica tetrahedra<\/a>. <strong>Polymers<\/strong> are chains, sheets, or three-dimensional structures, and are formed by multiple tetrahedra covalently <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> via their corner oxygen atoms. Pyroxenes are commonly found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">mafic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> rocks such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1666\">peridotite<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1013\">basalt<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1016\">gabbro<\/a>, as well as metamorphic rocks like eclogite and blue schist.<\/p>\n<p>Pyroxenes are built from long, single chains of polymerized <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silica tetrahedra<\/a> in which tetrahedra share two corner oxygens. The silica chains are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> together into the crystal structures by metal cations. A common member of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a> family is augite, itself containing several <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a> series with a complex chemical formula (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)<sub>2<\/sub>O<sub>6<\/sub> that gives rise to a number of individual <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> names.<\/p>\n<p>This single-chain crystalline structure <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> with many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>, which can also freely substitute for each other. The generalized chemical composition for <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a> is XZ(Al,Si)<sub>2<\/sub>O<sub>6<\/sub>. X represents the ions Na, Ca, Mg, or Fe, and Z represents Mg, Fe, or Al. These ions have similar ionic sizes, which allows many possible substitutions among them. Although the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1780\">cations<\/a> may freely substitute for each other in the crystal, they carry different ionic charges that must be balanced out in the final crystalline structure. For example Na has a charge of +1, but Ca has charge of +2. If a Na<sup>+<\/sup> ion substitutes for a Ca<sup>+2<\/sup> ion, it creates an unequal charge that must be balanced by other ionic substitutions elsewhere in the crystal. Note that ionic size is more important than ionic charge for substitutions to occur in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a> series in crystals.<\/p>\n<h3><\/h3>\n<h3><b>3.3.3 Amphibole Family<\/b><\/h3>\n<figure id=\"attachment_2773\" aria-describedby=\"caption-attachment-2773\" style=\"width: 200px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.15_Orthoclase_Hornblende.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2773\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.15_Orthoclase_Hornblende-300x300-1.jpg\" alt=\"A crystal of orthoclase (potassium feldspar) wth elongated dark crystals of hornblende\" width=\"200\" height=\"200\" \/><\/a><figcaption id=\"caption-attachment-2773\" class=\"wp-caption-text\">Elongated crystals of hornblende in orthoclase<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2772\" aria-describedby=\"caption-attachment-2772\" style=\"width: 200px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.16_Amphibole.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2772\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.16_Amphibole-300x236-1.jpg\" alt=\"Black crystals of hornblende\" width=\"200\" height=\"157\" \/><\/a><figcaption id=\"caption-attachment-2772\" class=\"wp-caption-text\">Hornblende crystals<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">Amphibole<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are built from polymerized double silica chains and they are also referred to as inosilicates. Imagine two <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a> chains that connect together by sharing a third oxygen on each tetrahedra.\u00a0 Amphiboles are usually found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> and metamorphic rocks and typically have a long-bladed <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a><\/strong>. The most common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a>, hornblende, is usually black; however, they come in a variety of colors depending on their chemical composition. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1762\">metamorphic rock<\/a>, amphibolite, is primarily composed of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/p>\n<figure id=\"attachment_2774\" aria-describedby=\"caption-attachment-2774\" style=\"width: 79px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.17_Tremolite-chain.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2774\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.17_Tremolite-chain-79x300-1.png\" alt=\"Double chain structure of amphibole; two single chains laying together with the inner corners of each tetrahedron bonded and the outer cornera active to bond with anions\" width=\"79\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2774\" class=\"wp-caption-text\">Double chain structure<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Amphiboles are composed of iron, magnesium, aluminum, and other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1780\">cations<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silica tetrahedra<\/a>. These dark ferromagnesian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are commonly found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1016\">gabbro<\/a>, baslt, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1015\">diorite<\/a>, and often form the black specks in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1014\">granite<\/a>. Their chemical formula is very complex and generally written as (RSi<sub>4<\/sub>O<sub>11<\/sub>)<sub>2<\/sub>, where R represents many different <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1780\">cations<\/a>. For example, it can also be written more exactly as AX<sub>2<\/sub>Z<sub>5<\/sub>((Si,Al,Ti)<sub>8<\/sub>O<sub>22<\/sub>)(OH,F,Cl,O)<sub>2<\/sub>. In this formula A may be Ca, Na, K, Pb, or blank; X equals Li, Na, Mg, Fe, Mn, or Ca; and Z is Li, Na, Mg, Fe, Mn, Zn, Co, Ni, Al, \u00a0Cr, Mn, V, Ti, or Zr. The substitutions create a wide variety of colors such as green, black, colorless, white, yellow, blue, or brown. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">Amphibole<\/a> crystals can also include hydroxide ions (OH<sup>&#8211;<\/sup>)<sup>,<\/sup> which occurs from an interaction between the growing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> and water dissolved in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>.<\/p>\n<h3><\/h3>\n<h3><\/h3>\n<h3><strong>3.3.4 Sheet Silicates<\/strong><\/h3>\n<figure id=\"attachment_2775\" aria-describedby=\"caption-attachment-2775\" style=\"width: 200px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.19_Biotite_aggregate_-_Ochtendung_Eifel_Germany.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2775\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.19_Biotite_aggregate_-_Ochtendung_Eifel_Germany-300x225-1.jpg\" alt=\"Dark brown crystals of biotite mica showing sheet-like habit\" width=\"200\" height=\"150\" \/><\/a><figcaption id=\"caption-attachment-2775\" class=\"wp-caption-text\">Sheet crystals of biotite mica<\/figcaption><\/figure>\n<figure id=\"attachment_3637\" aria-describedby=\"caption-attachment-3637\" style=\"width: 250px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/MicaSheetUSGOV.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-166\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MicaSheetUSGOV-300x226.jpg\" alt=\"Crystal of muscovite mica showing sheet structure of the mineral\" width=\"250\" height=\"188\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MicaSheetUSGOV-300x226.jpg 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MicaSheetUSGOV-65x49.jpg 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MicaSheetUSGOV-225x169.jpg 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MicaSheetUSGOV-350x263.jpg 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MicaSheetUSGOV.jpg 600w\" sizes=\"auto, (max-width: 250px) 100vw, 250px\" \/><\/a><figcaption id=\"caption-attachment-3637\" class=\"wp-caption-text\">Crystal of muscovite mica<\/figcaption><\/figure>\n<p>Sheet <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a> are built from tetrahedra which share all three of their bottom corner oxygens thus forming sheets of tetrahedra with their top corners available for <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonding<\/a> with other atoms. Micas and clays are common types of sheet <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a>, also known as phyllosilicates. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">Mica<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are usually found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> and metamorphic rocks, while clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are more often found in sedimentary rocks. Two frequently found micas are dark-colored <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">biotite<\/a>, frequently found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1014\">granite<\/a>, and light-colored <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">muscovite<\/a>, found in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1762\">metamorphic rock<\/a> called schist.<\/p>\n<figure id=\"attachment_2777\" aria-describedby=\"caption-attachment-2777\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.20_Silicate-sheet-3D-polyhedra.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2777\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.20_Silicate-sheet-3D-polyhedra-300x197-1.png\" alt=\"Continuous sheets of tetradedra with all three base corners bonded to each other; the top corner active to bond with anions\" width=\"300\" height=\"197\" \/><\/a><figcaption id=\"caption-attachment-2777\" class=\"wp-caption-text\">Sheet structure of mica<\/figcaption><\/figure>\n<p>Chemically, sheet <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a> usually contain silicon and oxygen in a 2:5 ratio (Si<sub>4<\/sub>O<sub>10<\/sub>). Micas contain mostly silica, aluminum, and potassium. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">Biotite<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">mica<\/a> has more iron and magnesium and is considered a ferromagnesian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">Muscovite<\/a> micas belong to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1006\">felsic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1006\">Felsic<\/a> is a contraction formed from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, the dominant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1006\">felsic<\/a> rocks.<\/p>\n<figure id=\"attachment_2778\" aria-describedby=\"caption-attachment-2778\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.21_Crystal-structure-of-mica.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2778\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.21_Crystal-structure-of-mica-300x300-1.jpg\" alt=\"Diagram of mica crystal structure with the sheets of tetrahedra inverted onto each other into sandwiches with the active corners bonded with anions and the sandwiches connected together with large potassium ions that form weak bonds easily separated so the crystal comes apart into sheets.\" width=\"300\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2778\" class=\"wp-caption-text\">Crystal structure of a mica<\/figcaption><\/figure>\n<figure id=\"attachment_2779\" aria-describedby=\"caption-attachment-2779\" style=\"width: 296px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Illmenite-mica-sandwich.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2779\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Illmenite-mica-sandwich-296x300-1.jpg\" alt=\"Silica sheets layered in mica like bread and hjam in a stack of sandwiches\" width=\"296\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2779\" class=\"wp-caption-text\">Mica \u00ab\u00a0silica sandwich\u00a0\u00bb structure<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>The illustration of the crystalline structure of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">mica<\/a> shows the corner O atoms <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> with K, Al, Mg, Fe, and Si atoms, forming polymerized sheets of linked tetrahedra, with an octahedral layer of Fe, Mg, or Al, between them.\u00a0 The yellow potassium ions form Van der Waals <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> (attraction and repulsion between atoms, molecules, and surfaces) and hold the sheets together. Van der Waals <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> differ from\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Covalent_bond\">covalent<\/a>\u00a0and\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Ionic_bond\">ionic<\/a>\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a>, and exist here between the sandwiches, holding them together into a stack of sandwiches. The Van der Waals <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> are weak compared to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> within the sheets, allowing the sandwiches to be separated along the potassium layers. This gives <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">mica<\/a> its characteristic property of easily cleaving into sheets.<\/p>\n<figure id=\"attachment_2780\" aria-describedby=\"caption-attachment-2780\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.22_Kaolinite-structure.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2780\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.22_Kaolinite-structure-300x244-1.jpg\" alt=\"Crystal structure of kaolinite, a clay mineral with sheet structure like mica except that the\" width=\"300\" height=\"244\" \/><\/a><figcaption id=\"caption-attachment-2780\" class=\"wp-caption-text\">Structure of kaolinite<\/figcaption><\/figure>\n<p>Clays <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> occur in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> formed by the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a> of rocks and are another family of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> with a tetrahedral sheet structure. Clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> form a complex family, and are an important component of many sedimentary rocks. Other sheet <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a> include serpentine and chlorite, found in metamorphic rocks.<\/p>\n<p>Clay <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are composed of hydrous aluminum <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a>. One type of clay, kaolinite, has a structure like an open-faced sandwich, with the bread being a single layer of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silicon-oxygen tetrahedra<\/a> and a layer of aluminum as the spread in an octahedral configuration with the top oxygens of the sheets.<\/p>\n<h3><b>3.3.5 Framework Silicates<\/b><\/h3>\n<figure id=\"attachment_2829\" aria-describedby=\"caption-attachment-2829\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Quartz-crystals.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2829\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Quartz-crystals-300x284-1.jpg\" alt=\"Freely grown quartz crystals showing crysatl faces\" width=\"300\" height=\"284\" \/><\/a><figcaption id=\"caption-attachment-2829\" class=\"wp-caption-text\">Freely growing quartz crystals showing crystal faces<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">Quartz<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> are the two most abundant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental crust<\/a>. In fact, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> itself is the single most abundant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> in the Earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>. There are two types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, one containing potassium and abundant in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1006\">felsic<\/a> rocks of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental crust<\/a>, and the other with sodium and calcium abundant in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">mafic<\/a> rocks of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic crust<\/a>.\u00a0 Together with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a>, these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are classified as framework <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a>. They are built with a three-dimensional framework of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silica tetrahedra<\/a> in which all four corner oxygens are shared with adjacent tetrahedra. Within these frameworks in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> are holes and spaces into which other ions like aluminum, potassium, sodium, and calcium can fit giving rise to a variety of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> compositions and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> names.<\/p>\n<figure id=\"attachment_2781\" aria-describedby=\"caption-attachment-2781\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/min-crust-pie-chart.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2781\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/min-crust-pie-chart-300x290-1.jpg\" alt=\"Feldspar is 51% of the chart.\" width=\"300\" height=\"290\" \/><\/a><figcaption id=\"caption-attachment-2781\" class=\"wp-caption-text\">Mineral abundance pie chart in Earth&rsquo;s crust by Callan Bentley.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">Feldspars<\/a> are usually found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> rocks, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1014\">granite<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1010\">rhyolite<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1013\">basalt<\/a> as well as metamorphic rocks and detrital sedimentary rocks. Detrital sedimentary rocks are composed of mechanically weathered rock particles, like sand and gravel. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">Quartz<\/a> is especially abundant in detrital sedimentary rocks because it is very resistant to disintegration by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>. While <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a> is the most abundant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> on the Earth&rsquo;s surface, due to its durability, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are the most abundant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> in the Earth&rsquo;s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>, comprising roughly 50% of the total <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that make up the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>.<\/p>\n<figure id=\"attachment_2782\" aria-describedby=\"caption-attachment-2782\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.24_kspar280x210-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2782\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.24_kspar280x210-1-300x200-1.jpg\" alt=\"A group of crystals of pink potassium feldspar\" width=\"300\" height=\"200\" \/><\/a><figcaption id=\"caption-attachment-2782\" class=\"wp-caption-text\">Pink orthoclase crystals<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">Quartz<\/a> is composed of pure silica, SiO<sub>2<\/sub>, with the tetrahedra arranged in a three dimensional framework. Impurities consisting of atoms within this framework give rise to many varieties of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a> among which are gemstones like amethyst, rose <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a>, and citrine.\u00a0 <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">Feldspars<\/a> are mostly silica with aluminum, potassium, sodium, and calcium. Orthoclase <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> (KAlSi<sub>3<\/sub>O<sub>8<\/sub>), also called potassium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">K-spar<\/a>, is made of silica, aluminum, and potassium. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">Quartz<\/a> and orthoclase <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1006\">felsic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1006\">Felsic<\/a> is the compositional term applied to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> and rocks that contain an abundance of silica. Another <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a> with the formula (Ca,Na)AlSi<sub>3<\/sub>O<sub>8<\/sub>, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a> (Ca,Na) indicating a series of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, one end of the series with calcium CaAl<sub>2<\/sub>Si<sub>2<\/sub>O<sub>8<\/sub>, called anorthite, and the other end with sodium NaAlSi<sub>3<\/sub>O<sub>8<\/sub>, called albite.\u00a0Note how the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> accommodates the substitution of Ca<sup>++<\/sup> and Na<sup>+<\/sup>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> in this solid solution series have different <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> names.<\/p>\n<figure id=\"attachment_2783\" aria-describedby=\"caption-attachment-2783\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/23-feldspar-structure.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2783\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/23-feldspar-structure-300x271-1.gif\" alt=\"Framework structure of feldspar with all corners of tetrahedra shared with adjacent tetrahedra; there are holes in the structure in which large anions like potassium and sodium\/calcium fit\" width=\"300\" height=\"271\" \/><\/a><figcaption id=\"caption-attachment-2783\" class=\"wp-caption-text\">Crystal structure of feldspar<\/figcaption><\/figure>\n<p>Note that aluminum, which has a similar ionic size to silicon, can substitute for silicon inside the tetrahedra (see figure). Because potassium ions are so much larger than sodium and calcium ions, which are very similar in size, the inability of the crystal lattice to accommodate both potassium and sodium\/calcium gives rise to the two families of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, orthoclase and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a> respectively.\u00a0Framework <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a> are called tectosilicates and include the alkali metal-rich feldspathoids and zeolites.<\/p>\n<h3><\/h3>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-19\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-19\" class=\"h5p-iframe\" data-content-id=\"19\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"3.3 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3752\" aria-describedby=\"caption-attachment-3752\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.3-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-175\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.3-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3752\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 3.3 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">3.4 Non-Silicate Minerals<\/span><\/h2>\n<figure id=\"attachment_2784\" aria-describedby=\"caption-attachment-2784\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Hanksite.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2784\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hanksite-300x200-1.jpg\" alt=\"The mineral is hexagonal and clear.\" width=\"300\" height=\"200\" \/><\/a><figcaption id=\"caption-attachment-2784\" class=\"wp-caption-text\">Hanksite, Na22K(SO4)9(CO3)2Cl, one of the few minerals that is considered a carbonate and a sulfate<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The crystal structure of non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> (see table) does not contain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silica-oxygen tetrahedra<\/a>. Many non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are economically important and provide metallic resources such as copper, lead, and iron. They also include valuable non-metallic products such as salt, construction materials, and fertilizer.<\/p>\n<table>\n<tbody>\n<tr>\n<td><b><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Mineral<\/a> \u00a0Group<\/b><\/td>\n<td><b>Examples<\/b><\/td>\n<td><b>Formula<\/b><\/td>\n<td><b>Uses<\/b><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">Native<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">gold, silver, copper<\/span><\/td>\n<td><span style=\"font-weight: 400\">Au, Ag, Cu<\/span><\/td>\n<td><span style=\"font-weight: 400\">Jewelry, coins, industry<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">Carbonates<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a>, dolomite <\/span><\/td>\n<td><span style=\"font-weight: 400\">CaCO<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">, CaMg(CO<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">)<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><\/td>\n<td><span style=\"font-weight: 400\">Lime, Portland cement<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">Oxides<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">hematite, magnetite, bauxite<\/span><\/td>\n<td><span style=\"font-weight: 400\">Fe<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><span style=\"font-weight: 400\">O<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">, Fe<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">O<\/span><sub><span style=\"font-weight: 400\">4<\/span><\/sub><span style=\"font-weight: 400\">, a mixture of aluminum <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">Ores of iron &amp; aluminum, pigments <\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_972\">Halides<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">halite, sylvite<\/span><\/td>\n<td><span style=\"font-weight: 400\">NaCl, KCl<\/span><\/td>\n<td><span style=\"font-weight: 400\">Table salt, fertilizer<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">Sulfides<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">galena, chalcopyrite, cinnabar<\/span><\/td>\n<td><span style=\"font-weight: 400\">PbS, CuFeS<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><span style=\"font-weight: 400\">, HgS<\/span><\/td>\n<td><span style=\"font-weight: 400\">Ores of lead, copper, mercury<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\">Sulphates<\/span><\/td>\n<td><span style=\"font-weight: 400\">gypsum, epsom salts<\/span><\/td>\n<td><span style=\"font-weight: 400\">CaSo<\/span><sub><span style=\"font-weight: 400\">4<\/span><\/sub><span style=\"font-weight: 400\">\u00b72H<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><span style=\"font-weight: 400\">O, MgSO<\/span><sub><span style=\"font-weight: 400\">4<\/span><\/sub><span style=\"font-weight: 400\">\u00b77H<\/span><sub><span style=\"font-weight: 400\">2<\/span><\/sub><span style=\"font-weight: 400\">O<\/span><\/td>\n<td><span style=\"font-weight: 400\">Sheetrock, therapeutic soak<\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_975\">Phosphates<\/a><\/span><\/td>\n<td><span style=\"font-weight: 400\">apatite<\/span><\/td>\n<td><span style=\"font-weight: 400\">Ca<\/span><sub><span style=\"font-weight: 400\">5<\/span><\/sub><span style=\"font-weight: 400\">(PO<\/span><sub><span style=\"font-weight: 400\">4<\/span><\/sub><span style=\"font-weight: 400\">)<\/span><sub><span style=\"font-weight: 400\">3<\/span><\/sub><span style=\"font-weight: 400\">(F,Cl,OH) <\/span><\/td>\n<td><span style=\"font-weight: 400\">Fertilizer, teeth, bones<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em><span style=\"font-weight: 400\">Common non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\"><em>silicate<\/em><\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\"><em>mineral<\/em><\/a> groups.<\/span><\/em><\/p>\n<h3><b>3.4.1 Carbonates<\/b><\/h3>\n<figure id=\"attachment_2785\" aria-describedby=\"caption-attachment-2785\" style=\"width: 245px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.26_Calcite-rhomb.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2785\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.26_Calcite-rhomb-245x300-1.jpg\" alt=\"Calcite crystal in a shape called a rhomb like a cube squahed over toward one corner\" width=\"245\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2785\" class=\"wp-caption-text\">Calcite crystal in shape of rhomb. Note the double-refracted word \u201ccalcite\u201d in the center of the figure due to birefringence.<\/figcaption><\/figure>\n<figure id=\"attachment_2786\" aria-describedby=\"caption-attachment-2786\" style=\"width: 200px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.29_Limestone_etched_section_KopeFm_new.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2786\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.29_Limestone_etched_section_KopeFm_new-281x300-1.jpg\" alt=\"Piece of limestone rock full of small fossils\" width=\"200\" height=\"214\" \/><\/a><figcaption id=\"caption-attachment-2786\" class=\"wp-caption-text\">Limestone with small fossils<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">Calcite<\/a>\u00a0(CaCO<sub>3<\/sub>) and dolomite (CaMg(CO<sub>3<\/sub>)<sub>2<\/sub>) are the two most frequently occurring <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, and usually occur in sedimentary rocks, such as limestone and dolostone rocks, respectively. Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> rocks, such <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> and dolomite, are formed via evaporation and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a>. However, most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a>-rich rocks, such as limestone, are created by the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1760\">lithification<\/a> of fossilized marine organisms. These organisms, including those we can see and many microscopic organisms, have shells or exoskeletons consisting of calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> (CaCO<sub>3<\/sub>). When these organisms die, their remains accumulate on the floor of the water body in which they live and the soft body parts decompose and dissolve away. The calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> hard parts become included in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>, eventually becoming the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1761\">sedimentary rock<\/a> called limestone. While limestone may contain large, easy to see <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a>, most limestones contain the remains of microscopic creatures and thus originate from biological processes.<\/p>\n<figure id=\"attachment_2787\" aria-describedby=\"caption-attachment-2787\" style=\"width: 282px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Bifringence.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2787\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bifringence-282x300-1.jpg\" alt=\"Calcite crystal polarize light into two waves that vibrate at right angles to each other and pass through the crystal in different paths.\" width=\"282\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2787\" class=\"wp-caption-text\">Bifringence in calcite crystals<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">Calcite<\/a> crystals show an interesting property called <strong>birefringence<\/strong>, meaning they polarize light into two wave components vibrating at right angles to each other. As the two light waves pass through the crystal, they travel at different velocities and are separated by refraction into two different travel paths. In other words, the crystal produces a double image of objects viewed through it. Because they polarize light, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> crystals are used in special petrographic microscopes for studying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> and rocks.<\/p>\n<p>Many non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are referred to as salts. The term <strong>salts<\/strong> used here refers to compounds made by replacing the hydrogen in natural acids. The most abundant natural acid is carbonic acid that forms by the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a> of carbon dioxide in water. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">Carbonate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are salts built around the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> ion (CO3<sup>-2<\/sup>) where calcium and\/or magnesium replace the hydrogen in carbonic acid (H<sub>2<\/sub>CO<sub>3<\/sub>). <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">Calcite<\/a> and a closely related polymorph aragonite are secreted by organisms to form shells and physical structures like corals. Many such creatures draw both calcium and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> from dissolved bicarbonate ions (HCO<sub>3<\/sub><sup>&#8211;<\/sup>) in ocean water. As seen in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> identification section below, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> is easily dissolved in acid and thus effervesces in dilute hydrochloric acid (HCl). Small dropper bottles of dilute hydrochloric acid are often carried by geologists in the field as well as used in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> identification labs.<\/p>\n<p>Other salts include halite (NaCl) in which sodium replaces the hydrogen in hydrochloric acid and gypsum (Ca[SO<sub>4<\/sub>] \u2022 2 H<sub>2<\/sub>O) in which calcium replaces the hydrogen in sulfuric acid. Note that some water molecules are also included in the gypsum crystal. Salts are often formed by evaporation and are called evaporite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/p>\n<figure id=\"attachment_2788\" aria-describedby=\"caption-attachment-2788\" style=\"width: 425px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.30_Crystal_structure_of_Calcite.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2788\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.30_Crystal_structure_of_Calcite.png\" alt=\"Crystal structure of calcite showing the carbonate units of carbon surrounded by three oxygen ions and bonded to calcium ions.\" width=\"425\" height=\"520\" \/><\/a><figcaption id=\"caption-attachment-2788\" class=\"wp-caption-text\">Crystal structure of calcite<\/figcaption><\/figure>\n<p>The figure shows the crystal structure of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> (CaCO<sub>3<\/sub>). Like silicon, carbon has four valence electrons. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> unit consists of carbon atoms (tiny white dots) covalently <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> to three oxygen atoms (red), one oxygen sharing two valence electrons with the carbon and the other two sharing one valence electron each with the carbon, thus creating triangular units with a charge of -2. The negatively charged <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> unit forms an ionic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a> with the Ca ion (blue), which as a charge of +2.<\/p>\n<h3><\/h3>\n<h3><\/h3>\n<h3><\/h3>\n<h3><\/h3>\n<h3><\/h3>\n<h3><b>3.4.2 Oxides, Halides, and Sulfides<\/b><\/h3>\n<figure id=\"attachment_2789\" aria-describedby=\"caption-attachment-2789\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.31_Iron_oxide_LimoniteUSGOV.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2789\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.31_Iron_oxide_LimoniteUSGOV-300x256-1.jpg\" alt=\"Image of limonite, a hydrated oxide of iron\" width=\"300\" height=\"256\" \/><\/a><figcaption id=\"caption-attachment-2789\" class=\"wp-caption-text\">Limonite, a hydrated oxide of iron<\/figcaption><\/figure>\n<p>After <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonates<\/a>, the next most common non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_972\">halides<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfides<\/a>.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">Oxides<\/a> consist of metal ions covalently <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> with oxygen. The most familiar <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a> is rust, which is a combination of iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a> (Fe<sub>2<\/sub>O<sub>3<\/sub>) and hydrated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a>. Hydrated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a> form when iron is exposed to oxygen and water. Iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a> are important for producing metallic iron. When iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a> or ore is smelted, it produces carbon dioxide (CO<sub>2<\/sub>) and metallic iron.<\/p>\n<p>The red color in rocks is usually due to the presence of iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a>. For example, the red sandstone cliffs in Zion National Park and throughout Southern Utah consist of white or colorless grains of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a> coated with iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a> which serve as cementing agents holding the grains together.<\/p>\n<figure id=\"attachment_2790\" aria-describedby=\"caption-attachment-2790\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.32_Hematite_-_oolitic_with_shale_Iron_Oxide_Clinton_Oneida_County_New_York-e1512421695503.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2790 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.32_Hematite_-_oolitic_with_shale_Iron_Oxide_Clinton_Oneida_County_New_York-e1512421695503-300x269-1.jpg\" alt=\"A red form of hematite called oolitic showing a mass of small round nodules\" width=\"300\" height=\"269\" \/><\/a><figcaption id=\"caption-attachment-2790\" class=\"wp-caption-text\">Oolitic hematite<\/figcaption><\/figure>\n<p>Other iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a> include limonite, magnetite, and hematite. Hematite occurs in many different crystal forms. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_985\">massive<\/a> form shows no external structure. Botryoidal hematite shows large concentric blobs. Specular hematite looks like a mass of shiny metallic crystals. Oolitic hematite looks like a mass of dull red fish eggs. These different forms of hematite are polymorphs and all have the same formula, Fe<sub>2<\/sub>O<sub>3<\/sub>.<\/p>\n<p>Other common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> include:<\/p>\n<ul>\n<li>ice (H<sub>2<\/sub>O), an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a> of hydrogen<\/li>\n<li>bauxite (Al<sub>2<\/sub>H<sub>2<\/sub>O<sub>4<\/sub>), hydrated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a> of aluminum, an ore for producing metallic aluminum<\/li>\n<li>corundum (Al<sub>2<\/sub>O<sub>3<\/sub>), which includes ruby and sapphire gemstones.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2791\" aria-describedby=\"caption-attachment-2791\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.34_Halite-249324-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2791\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.34_Halite-249324-1-300x225-1.jpg\" alt=\"Crystals of halite showing cubic crystal habit\" width=\"300\" height=\"225\" \/><\/a><figcaption id=\"caption-attachment-2791\" class=\"wp-caption-text\">Halite crystal showing cubic habit<\/figcaption><\/figure>\n<p>The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_972\">halides<\/a><\/strong> consist of halogens in column VII, usually fluorine or chlorine, ionically <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> with sodium or other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1780\">cations<\/a>. These include halite or sodium chloride (NaCl), common table salt; sylvite or potassium chloride (KCl); and fluorite or calcium fluoride (CaF<sub>2<\/sub>).<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2792\" aria-describedby=\"caption-attachment-2792\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.36_2014-07-05_13_04_30_View_across_the_Bonneville_Salt_Falts_Utah_from_ground_level.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2792\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.36_2014-07-05_13_04_30_View_across_the_Bonneville_Salt_Falts_Utah_from_ground_level-300x220-1.jpg\" alt=\"Photo of salt crust at the Bonneville Salt Flats in Utah with mountains in the background.\" width=\"300\" height=\"220\" \/><\/a><figcaption id=\"caption-attachment-2792\" class=\"wp-caption-text\">Salt crystals at the Bonneville Salt Flats<\/figcaption><\/figure>\n<figure id=\"attachment_2793\" aria-describedby=\"caption-attachment-2793\" style=\"width: 244px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.35_FluoriteUV-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2793\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.35_FluoriteUV-244x300-1.jpg\" alt=\"Purplish crystals of fluorite. The second image shows the deep blue fluorescence of fluorite under ultraviolet light.\" width=\"244\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2793\" class=\"wp-caption-text\">Fluorite. B shows fluorescence of fluorite under UV light<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_972\">Halide<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> usually form from the evaporation of sea water or other isolated bodies of water. A well-known example of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_972\">halide<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> deposits created by evaporation is the Bonneville Salt Flats, located west of the Great Salt Lake in Utah (see figure).<\/p>\n<p>&nbsp;<\/p>\n<p>Many important metal ores are <b><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfides<\/a>, <\/b><span style=\"font-weight: 400\">in which metals are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> to sulfur.\u00a0<\/span><span style=\"font-weight: 400\">Significant examples include: \u00a0<\/span>galena<span style=\"font-weight: 400\"> (lead <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>), <\/span>sphalerite<span style=\"font-weight: 400\"> (zinc <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>),<\/span> pyrite<\/p>\n<figure id=\"attachment_2794\" aria-describedby=\"caption-attachment-2794\" style=\"width: 175px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.37_pyrite1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2794\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.37_pyrite1-283x300-1.jpg\" alt=\"Cubic crystals of iron pyrite, called &quot;fools gold&quot;\" width=\"175\" height=\"185\" \/><\/a><figcaption id=\"caption-attachment-2794\" class=\"wp-caption-text\">Cubic crystals of pyrite<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\">(<\/span><span style=\"font-weight: 400\">iron<\/span><span style=\"font-weight: 400\">\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>, sometimes called \u201cfool&rsquo;s gold\u201d), and <\/span>chalcopyrite <span style=\"font-weight: 400\">(iron-copper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>).<\/span><span style=\"font-weight: 400\">\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">Sulfides<\/a> are well known for being important ore <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. For example, galena is the main source of lead, sphalerite is the main source of zinc, and chalcopyrite is the main copper ore <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> mined in porphyry deposits like the Bingham mine (see <a href=\"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/16-energy-and-mineral-resources\/\">chapter 16<\/a>). The largest sources of nickel, antimony, molybdenum, arsenic, and mercury are also <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfides<\/a>.<\/span><\/p>\n<h3><b>3.4.3 Sulfates<\/b><\/h3>\n<figure id=\"attachment_2795\" aria-describedby=\"caption-attachment-2795\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.39_SeleniteGypsumUSGOV.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2795\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.39_SeleniteGypsumUSGOV-300x284-1.jpg\" alt=\"A clear crystal of gypsum\" width=\"300\" height=\"284\" \/><\/a><figcaption id=\"caption-attachment-2795\" class=\"wp-caption-text\">Gypsum crystal<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_974\">Sulfate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> contain a metal ion, such as calcium, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonded<\/a> to a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_974\">sulfate<\/a> ion. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_974\">sulfate<\/a> ion is a combination of sulfur and oxygen (SO<sub>4<sup>&#8211;<\/sup><\/sub><sup>2<\/sup>). The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_974\">sulfate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> gypsum (CaSO<sub>4<\/sub>\u14272H<sub>2<\/sub>O) is used in construction materials such as plaster and drywall. Gypsum is often formed from evaporating water and usually contains water molecules in its crystalline structure. The \u14272H<sub>2<\/sub>O in the formula indicates the water molecules are whole H<sub>2<\/sub>O. This is different from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a>, which contain a hydroxide ion (OH<sup>&#8211;<\/sup>) that is derived from water, but is missing a hydrogen ion (H<sup>+<\/sup>). The calcium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_974\">sulfate<\/a> without water is a different <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> than gypsum called anhydrite (CaSO<sub>4<\/sub>).<\/p>\n<h3><b>3.4.4 Phosphates<\/b><\/h3>\n<figure id=\"attachment_2796\" aria-describedby=\"caption-attachment-2796\" style=\"width: 150px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.40_Apatite_Canada.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2796\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.40_Apatite_Canada-236x300-1.jpg\" alt=\"A crystal of apatite\" width=\"150\" height=\"191\" \/><\/a><figcaption id=\"caption-attachment-2796\" class=\"wp-caption-text\">Apatite crystal<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_975\">Phosphate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> have a tetrahedral <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_975\">phosphate<\/a> unit (PO<sub>4<\/sub><sup>-3<\/sup>) combined with various <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1782\">anions<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1780\">cations<\/a>. In some cases arsenic or vanadium can substitute for phosphorus. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_975\">Phosphates<\/a> are an important ingredient of fertilizers as well as detergents, paint, and other products. The best known <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_975\">phosphate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> is apatite, Ca<sub>5<\/sub>(PO<sub>4<\/sub>)<sub>3<\/sub>(F,Cl,OH), variations of which are found in teeth and bones. The gemstone turquoise [CuAl<sub>6<\/sub>(PO<sub>4<\/sub>)<sub>4<\/sub>(OH)<sub>8<\/sub>\u00b74H2O ] is a copper-rich <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_975\">phosphate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> that, like gypsum, contains water molecules.<\/span><\/p>\n<h3><b>3.4.5 Native Element Minerals<\/b><\/h3>\n<figure id=\"attachment_2798\" aria-describedby=\"caption-attachment-2798\" style=\"width: 200px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.43_Sulfer_Fumarola_Vulcano.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2798\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.43_Sulfer_Fumarola_Vulcano-300x225-1.jpg\" alt=\"Native sulfur deposited around the vent of a volcanic fumarole\" width=\"200\" height=\"150\" \/><\/a><figcaption id=\"caption-attachment-2798\" class=\"wp-caption-text\">Native sulfur deposited around a volcanic fumarole<\/figcaption><\/figure>\n<figure id=\"attachment_2797\" aria-describedby=\"caption-attachment-2797\" style=\"width: 200px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.41_Native_Copper-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2797\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.41_Native_Copper-1-300x284-1.jpg\" alt=\"Metallic native copper\" width=\"200\" height=\"189\" \/><\/a><figcaption id=\"caption-attachment-2797\" class=\"wp-caption-text\">Native copper<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">Native element minerals<\/a>, usually metals, occur in nature in a pure or nearly pure state. Gold is an example of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>; it is not very reactive and rarely <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> with other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> so it is usually found in an isolated or pure state. The non-metallic and poorly-reactive <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> carbon is often found as a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>, such as graphite and diamonds. Mildly reactive metals like silver, copper, platinum, mercury, and sulfur sometimes occur as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native element minerals<\/a>. Reactive metals such as iron, lead, and aluminum almost always <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a> to other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> and are rarely found in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a> state.<\/p>\n<h3><\/h3>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-20\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-20\" class=\"h5p-iframe\" data-content-id=\"20\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"3.4 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3751\" aria-describedby=\"caption-attachment-3751\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.4-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-191\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.4-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3751\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 3.4 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">3.5 Identifying Minerals<\/span><\/h2>\n<figure id=\"attachment_2799\" aria-describedby=\"caption-attachment-2799\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Curiosity_Mars_Rover_Finds_Mineral_Match.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2799\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Curiosity_Mars_Rover_Finds_Mineral_Match-300x268-1.jpg\" alt=\"The red rocks have a small hole drilled\" width=\"300\" height=\"268\" \/><\/a><figcaption id=\"caption-attachment-2799\" class=\"wp-caption-text\">The rover Curiosity drilled a hole in this rock from Mars, and confirmed the mineral Hematite, as mapped from satellites.<\/figcaption><\/figure>\n<p>Geologists identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> by their physical properties. In the field, where geologists may have limited access to advanced technology and powerful machines, they can still identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> by testing several physical properties: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a> and color, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">hardness<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a>, cleavage and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a>, and some special properties. Only a few common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> make up the majority of Earth&rsquo;s rocks and are usually seen as small grains in rocks. Of the several properties used for identifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, it is good to consider which will be most useful for identifying them in small grains surrounded by other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/p>\n<h3><b>3.5.1 Luster and Color<\/b><\/h3>\n<figure id=\"attachment_2800\" aria-describedby=\"caption-attachment-2800\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Molly_Hill_molybdenite.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2800\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Molly_Hill_molybdenite-300x225-1.jpg\" alt=\"The crystal looks like metal.\" width=\"300\" height=\"225\" \/><\/a><figcaption id=\"caption-attachment-2800\" class=\"wp-caption-text\">15 mm metallic hexagonal molybdenite crystal from Quebec.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The first thing to notice about a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> is its surface appearance, specifically <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a> and color. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">Luster<\/a> describes how the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> looks. Metallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a> looks like a shiny metal such as chrome, steel, silver, or gold. Submetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a> has a duller appearance. Pewter, for example, shows submetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a>.<\/p>\n<figure id=\"attachment_2801\" aria-describedby=\"caption-attachment-2801\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Pewter-plate.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2801\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Pewter-plate-300x280-1.jpg\" alt=\"Antique pewter plate showing a more dull submetallic luster\" width=\"300\" height=\"280\" \/><\/a><figcaption id=\"caption-attachment-2801\" class=\"wp-caption-text\">Submetallic luster shown on an antique pewter plate.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>Nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a> doesn\u2019t look like a metal and may be described as vitreous (glassy), earthy, silky, pearly, and other surface qualities. Nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> may be shiny, although their vitreous shine is different from metallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a>. See the table for descriptions and examples of nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a>.<\/p>\n<table style=\"width: 680px;height: 859px\">\n<tbody>\n<tr style=\"height: 32.625px\">\n<th style=\"border-color: #000000;background-color: #1ae8de;text-align: center;vertical-align: middle\"><span style=\"text-decoration: underline\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">Luster<\/a><\/span><\/th>\n<th style=\"border-color: #000000;background-color: #1ae8de;text-align: center;vertical-align: middle\"><span style=\"text-decoration: underline\">Image<\/span><\/th>\n<th style=\"border-color: #000000;background-color: #1ae8de;text-align: center;vertical-align: middle\"><span style=\"text-decoration: underline\">Description<\/span><\/th>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Vitreous\/glassy<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_3669\" aria-describedby=\"caption-attachment-3669\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.23_-Quartz_Bresil.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-195\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.23_-Quartz_Bresil-150x150.jpg\" alt=\"A mass of quartz crystals showing typical six sided habit with points\" width=\"150\" height=\"150\" \/><\/a><figcaption id=\"caption-attachment-3669\" class=\"wp-caption-text\">Quartz crystals<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Surface is shiny like glass<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Earthy\/dull<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2802\" aria-describedby=\"caption-attachment-2802\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.47_earthy_luster_KaolinUSGOV-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-2802\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.47_earthy_luster_KaolinUSGOV-1-150x150-1.jpg\" alt=\"Specimen of kaolin, a clay oineral, showing dull or earthy luster\" width=\"150\" height=\"150\" \/><\/a><figcaption id=\"caption-attachment-2802\" class=\"wp-caption-text\">Kaolin specimen showing dull or earthy luster<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Dull, like dried mud or clay<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Silky<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2803\" aria-describedby=\"caption-attachment-2803\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.48_silky_luster_Selenite_Gips_Marienglas-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2803\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.48_silky_luster_Selenite_Gips_Marienglas-1-300x230-1.jpg\" alt=\"Specimen showing silky luster\" width=\"150\" height=\"115\" \/><\/a><figcaption id=\"caption-attachment-2803\" class=\"wp-caption-text\">Specimen showing silky luster<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Soft shine like silk fabric<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Pearly<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2804\" aria-describedby=\"caption-attachment-2804\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.49_pearly_luster_Mineral_Mica_GDFL006.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2804\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.49_pearly_luster_Mineral_Mica_GDFL006-300x218-1.jpg\" alt=\"Specimen showing pearly luster like the inside of a clam shell\" width=\"150\" height=\"109\" \/><\/a><figcaption id=\"caption-attachment-2804\" class=\"wp-caption-text\">Specimen showing pearly luster<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Like the inside of a clam shell or mother-of-pearl<\/td>\n<\/tr>\n<tr style=\"height: 28px\">\n<td style=\"width: 155px;height: 28px;text-align: center;vertical-align: middle\">Submetallic<\/td>\n<td style=\"width: 148px;height: 28px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2805\" aria-describedby=\"caption-attachment-2805\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.44_submetallic_Sphalerite4.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2805\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.44_submetallic_Sphalerite4-300x277-1.jpg\" alt=\"Photo of mineral exhibiting submetallic luster\" width=\"150\" height=\"138\" \/><\/a><figcaption id=\"caption-attachment-2805\" class=\"wp-caption-text\">Submetallic luster on sphalerite<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 333px;height: 28px;text-align: center;vertical-align: middle\">Has the appearance of dull metal,\u00a0like pewter. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> would usually still be considered metallic. Submetallic appearance can occur in metallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> because of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<figure id=\"attachment_2806\" aria-describedby=\"caption-attachment-2806\" style=\"width: 245px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Azurite_in_siltstone_Malbunka_mine_NT.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2806\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Azurite_in_siltstone_Malbunka_mine_NT-245x300-1.jpg\" alt=\"There are two dark blue disks on white siltstone.\" width=\"245\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2806\" class=\"wp-caption-text\">Azurite is ALWAYS a dark blue color, and has been used for centuries for blue pigment.<\/figcaption><\/figure>\n<p>Surface color may be helpful in identifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, although it can be quite variable within the same <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> family. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Mineral<\/a> colors are affected by the main <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> as well as impurities in the crystals. These impurities may be rare <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>\u2014like manganese, titanium, chromium, or lithium\u2014even other molecules that are not normally part of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> formula. For example, the incorporation of water molecules gives <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a>, which is normally clear, a milky color.<\/p>\n<p>Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> predominantly show a single color. Malachite and azurite are green and blue, respectively, because of their copper content. Other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> have a predictable range of colors due to elemental substitutions, usually via a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">Feldspars<\/a>, the most abundant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> in the earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>, are complex, have <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1786\">solid solution<\/a> series, and present several colors including pink, white, green, gray and others. Other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> also come in several colors, influenced by trace amounts of several <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. The same <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> may show up as different colors, in different <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. With notable exceptions, color is usually not a definitive property of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. For identifying many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. a more reliable indicator is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a>, which is the color of the powdered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>.<\/p>\n<h3><b>3.5.2 Streak<\/b><\/h3>\n<figure id=\"attachment_2807\" aria-describedby=\"caption-attachment-2807\" style=\"width: 450px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.50_Streak_plate_with_Pyrite_and_Rhodochrosite-1-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2807\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.50_Streak_plate_with_Pyrite_and_Rhodochrosite-1-300x227-1.jpg\" alt=\"Pyrite showing a black streak on a white streak plate and rhodochrosite with a white streak on a black streak plate\" width=\"450\" height=\"341\" \/><\/a><figcaption id=\"caption-attachment-2807\" class=\"wp-caption-text\">Different minerals may have different streaks<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">Streak<\/a> examines the color of a powdered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>, and can be seen when a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> sample is scratched or scraped on an unglazed porcelain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>. A paper page in a field notebook may also be used for the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a> of some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> that are harder than the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> will not show <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a>, but will scratch the porcelain. For these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a> test can be obtained by powdering the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> with a hammer and smearing the powder across a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> or notebook paper.<\/p>\n<p>While <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> surface colors and appearances may vary, their <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a> colors can be diagnostically useful. An example of this property is seen in the iron-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> hematite. Hematite occurs in a variety of forms, colors and lusters, from shiny metallic silver to earthy red-brown, and different physical appearances. A hematite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a> is consistently reddish brown, no matter what the original specimen looks like. Iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a> or pyrite, is a brassy metallic yellow. Commonly named fool\u2019s gold, pyrite has a characteristic black to greenish-black <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a>.<\/p>\n<h3><b>3.5.3 Hardness<\/b><\/h3>\n<figure id=\"attachment_2808\" aria-describedby=\"caption-attachment-2808\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.51_Mohs_Scale2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-large wp-image-2808\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.51_Mohs_Scale2-1024x714-1.jpg\" alt=\"Chart of Mohs Hardness Scale with minerals arranged in hardness from 1 to 10, also showing common items that correlate with the scale.\" width=\"1024\" height=\"714\" \/><\/a><figcaption id=\"caption-attachment-2808\" class=\"wp-caption-text\">Mohs Hardness Scale<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">Hardness<\/a> measures the ability of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> to scratch other substances. The Mohs <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">Hardness<\/a> Scale gives a number showing the relative scratch-resistance of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> when compared to a standardized set of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> of increasing hardness. The Mohs scale was developed by German geologist Fredrick Mohs in the early 20th century, although the idea of identifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">hardness<\/a> goes back thousands of years. Mohs <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">hardness<\/a> values are determined by the strength of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u2019s atomic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a>.<\/p>\n<p>The figure shows the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> associated with specific <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">hardness<\/a> values, together with some common items readily available for use in field testing and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> identification. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">hardness<\/a> values run from 1 to 10, with 10 being the hardest; however, the scale is not linear. Diamond defines a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">hardness<\/a> of 10 and is actually about four times harder than corundum, which is 9. A steel pocketknife blade, which has a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">hardness<\/a> value of 5.5, separates between hard and soft <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> on many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> identification keys.<\/p>\n<h3><b>3.5.4 Crystal Habit<\/b><\/h3>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> can be identified by <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a><\/strong>, how their crystals grow and appear in rocks. Crystal shapes are determined by the arrangement of the atoms within the crystal structure. For example, a cubic arrangement of atoms gives rise to a cubic-shaped <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> crystal. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">Crystal habit<\/a> refers to typically observed shapes and characteristics; however, they can be affected by other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> crystallizing in the same rock. When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are constrained so they do not develop their typical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a>, they are called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_981\">anhedral<\/a><\/strong>. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_982\">Subhedral<\/a><\/strong> crystals are partially formed shapes. For some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> characteristic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a> is to grow crystal faces even when surrounded by other crystals in rock. An example is garnet. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> grown freely where the crystals are unconstrained and can take characteristic shapes often form crystal faces. A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_983\">euhedral<\/a><\/strong> crystal has a perfectly formed, unconstrained shape. Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> crystallize in such tiny crystals, they do not show a specific <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a> to the naked eye. Other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, like pyrite, can have an array of different crystal habits, including cubic, dodecahedral, octahedral, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_985\">massive<\/a>. The table lists typical crystal habits of various <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/p>\n<table style=\"width: 687px;height: 3774px\">\n<tbody>\n<tr>\n<th style=\"border-color: #000000;background-color: #6be86f;text-align: center;vertical-align: middle\" scope=\"row\"><strong><span style=\"text-decoration: underline\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">Habit<\/a><\/span><\/strong><\/th>\n<th style=\"border-color: #000000;background-color: #6be86f;text-align: center;vertical-align: middle\" scope=\"row\"><strong><span style=\"text-decoration: underline\">Image<\/span><\/strong><\/th>\n<th style=\"border-color: #000000;background-color: #6be86f;text-align: center;vertical-align: middle\" scope=\"row\"><strong><span style=\"text-decoration: underline\">Examples<\/span><\/strong><\/th>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Bladed<\/strong><\/p>\n<p>long and flat crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2809\" aria-describedby=\"caption-attachment-2809\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Kyanite_crystals.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2809\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Kyanite_crystals-300x225-1.jpg\" alt=\"The crystals are long and rectangular\" width=\"150\" height=\"113\" \/><\/a><figcaption id=\"caption-attachment-2809\" class=\"wp-caption-text\">Bladed kyanite<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">kyanite,\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a>, gypsum<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Botryoidal\/mammillary<\/strong><\/p>\n<p>blobby, circular crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2810\" aria-describedby=\"caption-attachment-2810\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Malachite_Kolwezi_Katanga_Congo.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2810\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Malachite_Kolwezi_Katanga_Congo-300x174-1.jpg\" alt=\"The mineral is bulbous\" width=\"150\" height=\"87\" \/><\/a><figcaption id=\"caption-attachment-2810\" class=\"wp-caption-text\">Malachite from the Congo<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">hematite, malachite, smithsonite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Coating\/laminae\/druse<\/strong><\/p>\n<p>crystals that are small and coat surfaces<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2811\" aria-describedby=\"caption-attachment-2811\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ametyst-geode.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2811\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ametyst-geode-300x200-1.jpg\" alt=\"The rock is hollowed and filled with purple minerals\" width=\"150\" height=\"100\" \/><\/a><figcaption id=\"caption-attachment-2811\" class=\"wp-caption-text\">Quartz (var. amethyst) geode<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a>, malachite, azurite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Cubic<\/strong><\/p>\n<p>cube-shaped crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2812\" aria-describedby=\"caption-attachment-2812\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.55_Cubic_Calcite-Galena-elm56c.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2812\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.55_Cubic_Calcite-Galena-elm56c-260x300-1.jpg\" alt=\"Cubic crystals of galena, a sulfide of lead\" width=\"150\" height=\"173\" \/><\/a><figcaption id=\"caption-attachment-2812\" class=\"wp-caption-text\">Cubic crystals of galena<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">pyrite, galena, halite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Dodecahedral<\/strong><\/p>\n<p>12-sided polygon shapes<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2813\" aria-describedby=\"caption-attachment-2813\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.53_habit_dodecahedral_Pyrite_elbe-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2813\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.53_habit_dodecahedral_Pyrite_elbe-300x195-1.jpg\" alt=\"Crystals of pyrite showing dodecahedral habit\" width=\"150\" height=\"97\" \/><\/a><figcaption id=\"caption-attachment-2813\" class=\"wp-caption-text\">Pyrite crystals with dodecahedral habit<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">garnet, pyrite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Dendritic<\/strong><\/p>\n<p>branching crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2814\" aria-describedby=\"caption-attachment-2814\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Dendrites01.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2814\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Dendrites01-300x203-1.jpg\" alt=\"The mineral look like a fern. They are black and branching.\" width=\"150\" height=\"101\" \/><\/a><figcaption id=\"caption-attachment-2814\" class=\"wp-caption-text\">Manganese dendrites, scale in mm.<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">Mn-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a>, copper, gold<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_984\">Equant<\/a><\/strong><\/p>\n<p>crystals that do not have a long direction<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2815\" aria-describedby=\"caption-attachment-2815\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Peridot2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-209\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2-272x300.jpg\" alt=\"The crystal is light green.\" width=\"150\" height=\"165\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2-272x300.jpg 272w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2-929x1024.jpg 929w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2-768x847.jpg 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2-65x72.jpg 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2-225x248.jpg 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2-350x386.jpg 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peridot2.jpg 1190w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-2815\" class=\"wp-caption-text\">Large olivine crystal<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a>, garnet, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Fibrous<\/strong><\/p>\n<p>thin, very long crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2816\" aria-describedby=\"caption-attachment-2816\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tremolite_Campolungo.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2816\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tremolite_Campolungo-300x186-1.jpg\" alt=\"It is white and fiberous\" width=\"150\" height=\"93\" \/><\/a><figcaption id=\"caption-attachment-2816\" class=\"wp-caption-text\">Tremolite, a type of amphibole<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">serpentine, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a>, zeolite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Layered, sheets<\/strong><\/p>\n<p>stacked, very thin, flat crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2817\" aria-describedby=\"caption-attachment-2817\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.18_Muscovite-Albite-122887.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2817\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.18_Muscovite-Albite-122887-300x254-1.jpg\" alt=\"Sheets of muscovite mica in crystal mass\" width=\"150\" height=\"127\" \/><\/a><figcaption id=\"caption-attachment-2817\" class=\"wp-caption-text\">Sheet crystals of muscovite<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">mica <\/a>(<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">biotite<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">muscovite<\/a>, etc.)<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Lenticular\/platy<\/strong><\/p>\n<p>crystals that are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>-like<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2818\" aria-describedby=\"caption-attachment-2818\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Calcite-Wulfenite-tcw15b.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2818\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-Wulfenite-tcw15b-251x300-1.jpg\" alt=\"The orange wulfenite is bladed\" width=\"150\" height=\"179\" \/><\/a><figcaption id=\"caption-attachment-2818\" class=\"wp-caption-text\">Orange wulfenite on calcite<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">selenite roses, wulfenite, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Hexagonal<\/strong><\/p>\n<p>crystals with six sides<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_3687\" aria-describedby=\"caption-attachment-3687\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Hanksite-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-213 size-thumbnail\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hanksite-1-150x150.jpg\" alt=\"The mineral is hexagonal and clear.\" width=\"150\" height=\"150\" \/><\/a><figcaption id=\"caption-attachment-3687\" class=\"wp-caption-text\">Hexagonal hanksite<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a>, hanksite, corundum<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_985\">Massive<\/a>\/granular<\/strong><\/p>\n<p>Crystals with no obvious shape, microscopic crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2789\" aria-describedby=\"caption-attachment-2789\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.31_Iron_oxide_LimoniteUSGOV.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2789\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.31_Iron_oxide_LimoniteUSGOV-300x256-1.jpg\" alt=\"Image of limonite, a hydrated oxide of iron\" width=\"150\" height=\"128\" \/><\/a><figcaption id=\"caption-attachment-2789\" class=\"wp-caption-text\">Limonite, a hydrated oxide of iron<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">limonite, pyrite, azurite, bornite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Octahedral<\/strong><\/p>\n<p>4-sided double pyramid crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2819\" aria-describedby=\"caption-attachment-2819\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.62_octahedral_cleavage_Fluorite_crystals_rotated_90.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2819\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.62_octahedral_cleavage_Fluorite_crystals_rotated_90-300x182-1.jpg\" alt=\"Perfedt octahedral cleavage in fluorite generates octagon-shaped cleavage flakes.\" width=\"150\" height=\"91\" \/><\/a><figcaption id=\"caption-attachment-2819\" class=\"wp-caption-text\">Octagonal cleavage in fluorite<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">diamond, fluorite, magnetite, pyrite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Prismatic\/columnar<\/strong><\/p>\n<p>very long, cylindrical crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2820\" aria-describedby=\"caption-attachment-2820\" style=\"width: 142px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tourmaline.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2820\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tourmaline-142x300-1.jpg\" alt=\"The mineral is a long cylinder.\" width=\"142\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2820\" class=\"wp-caption-text\">Columnar tourmaline<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">tourmaline, beryl, barite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Radiating<\/strong><\/p>\n<p>crystals that grow from a point and fan out<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2821\" aria-describedby=\"caption-attachment-2821\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Pyrophyllite-236595.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2821\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Pyrophyllite-236595-217x300-1.jpg\" alt=\"The mineral is orange\" width=\"150\" height=\"207\" \/><\/a><figcaption id=\"caption-attachment-2821\" class=\"wp-caption-text\">Pyrophyllite<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">pyrite \u00ab\u00a0suns\u00a0\u00bb, pyrophyllite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Rhombohedral<\/strong><\/p>\n<p>crystals shaped like slanted cubes<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2785\" aria-describedby=\"caption-attachment-2785\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.26_Calcite-rhomb.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2785\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.26_Calcite-rhomb-245x300-1.jpg\" alt=\"Calcite crystal in a shape called a rhomb like a cube squahed over toward one corner\" width=\"150\" height=\"183\" \/><\/a><figcaption id=\"caption-attachment-2785\" class=\"wp-caption-text\">Calcite crystal in shape of rhomb.<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a>, dolomite<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Tabular\/blocky\/stubby<\/strong><\/p>\n<p>sharp-sided crystals with no long direction<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2770\" aria-describedby=\"caption-attachment-2770\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.14_Diopside-172005.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2770\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.14_Diopside-172005-300x231-1.jpg\" alt=\"Dark green crystals of diopside, a member of the pyroxene family\" width=\"150\" height=\"116\" \/><\/a><figcaption id=\"caption-attachment-2770\" class=\"wp-caption-text\">Crystals of diopside, a member of the pyroxene family<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 196px;text-align: center;vertical-align: middle\"><strong>Tetrahedral<\/strong><\/p>\n<p>three-sided, pyramid-shaped crystals<\/td>\n<td style=\"width: 133px;text-align: center;vertical-align: middle\">\n<figure id=\"attachment_2822\" aria-describedby=\"caption-attachment-2822\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Tetrahedrite-Chalcopyrite-Sphalerite-251531.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2822\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tetrahedrite-Chalcopyrite-Sphalerite-251531-300x218-1.jpg\" alt=\"The dark brown mineral is triangular\" width=\"150\" height=\"109\" \/><\/a><figcaption id=\"caption-attachment-2822\" class=\"wp-caption-text\">Tetrahedrite<\/figcaption><\/figure>\n<\/td>\n<td style=\"width: 312px;text-align: center;vertical-align: middle\">magnetite, spinel, tetrahedrite<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2824\" aria-describedby=\"caption-attachment-2824\" style=\"width: 150px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/GypsumStriations.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2824\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/GypsumStriations-251x300-1.jpg\" alt=\"The mineral has many parallel lines on it\" width=\"150\" height=\"179\" \/><\/a><figcaption id=\"caption-attachment-2824\" class=\"wp-caption-text\">Gypsum with striations<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2823\" aria-describedby=\"caption-attachment-2823\" style=\"width: 150px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Staurolite-62645.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2823\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Staurolite-62645-279x300-1.jpg\" alt=\"The brown minerals are replicated in different directions\" width=\"150\" height=\"161\" \/><\/a><figcaption id=\"caption-attachment-2823\" class=\"wp-caption-text\">Twinned staurolite<\/figcaption><\/figure>\n<p>Another <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a> that may be used to identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> is striations, which are dark and light parallel lines on a crystal face. Twinning is another, which occurs when the crystal structure replicates in mirror images along certain directions in the crystal.<\/p>\n<figure id=\"attachment_2825\" aria-describedby=\"caption-attachment-2825\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.65_Striations_in_plagioclase.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2825\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.65_Striations_in_plagioclase-300x242-1.jpg\" alt=\"Striations or parallel dark lines on one cleavage surface on plagioclase feldspar\" width=\"300\" height=\"242\" \/><\/a><figcaption id=\"caption-attachment-2825\" class=\"wp-caption-text\">Striations on plagioclase<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Striations and twinning are related properties in some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> including <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>. Striations are optical lines on a cleavage surface. Because of twinning in the crystal, striations show up on one of the two cleavage faces of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a> crystal.<\/p>\n<h3><b>3.5.5 Cleavage and Fracture<\/b><\/h3>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> often show characteristic patterns of breaking along specific cleavage planes or show characteristic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a> patterns. Cleavage planes are smooth, flat, parallel planes within the crystal. The cleavage planes may show as reflective surfaces on the crystal, as parallel cracks that penetrate into the crystal, or show on the edge or side of the crystal as a series of steps like rice terraces. Cleavage arises in crystals where the atomic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> between atomic layers are weaker along some directions than others, meaning they will break preferentially along these planes.\u00a0Because they develop on atomic surfaces in the crystal, cleavage planes are optically smooth and reflect light, although the actual break on the crystal may appear jagged or uneven. In such cleavages, the cleavage surface may appear like rice terraces on a mountainside that all reflect sunlight from a particular sun angle. Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> have a strong cleavage, some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> only have weak cleavage or do not typically demonstrate cleavage.<\/p>\n<figure id=\"attachment_2826\" aria-describedby=\"caption-attachment-2826\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.57_conchoidal_Citrine-sample2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2826\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.57_conchoidal_Citrine-sample2-300x225-1.jpg\" alt=\"A specimen of a variety of quartz showing conchoidal fracture\" width=\"300\" height=\"225\" \/><\/a><figcaption id=\"caption-attachment-2826\" class=\"wp-caption-text\">Citrine, a variety of quartz showing conchoidal fracture<\/figcaption><\/figure>\n<p>For example, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">olivine<\/a> rarely show cleavage and typically break into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_987\">conchoidal<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a> patterns.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2827\" aria-describedby=\"caption-attachment-2827\" style=\"width: 452px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/cryview_graphite_v1.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2827 size-full\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/cryview_graphite_v1.gif\" alt=\"Structure of graphite, showing single carbon layers with weak bonds holding them together\" width=\"452\" height=\"504\" \/><\/a><figcaption id=\"caption-attachment-2827\" class=\"wp-caption-text\">Graphite showing layers of carbon atoms separated by a gap with weak bonds holding the layers together.<\/figcaption><\/figure>\n<p>Graphite has its carbon atoms arranged into layers with relatively strong <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> within the layer and very weak <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> between the layers.\u00a0 Thus graphite cleaves readily between the layers and the layers slide easily over one another giving graphite its lubricating quality.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Mineral<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a> surfaces may be rough and uneven or they may be show <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_987\">conchoidal<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a>. Uneven <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a> patterns are described as irregular, splintery, fibrous. A conchoidal fracture has a smooth, curved surface like a shallow bowl or conch shell, often with curved ridges. Natural <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> glass, called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_999\">obsidian<\/a>, breaks with this characteristic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_987\">conchoidal<\/a> pattern<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2828\" aria-describedby=\"caption-attachment-2828\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.64_galena_cleavage_Argentiferous_Galena-458851.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2828 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.64_galena_cleavage_Argentiferous_Galena-458851-300x261-1.jpg\" alt=\"Specimen of galena showing cubic cleavage\" width=\"300\" height=\"261\" \/><\/a><figcaption id=\"caption-attachment-2828\" class=\"wp-caption-text\">Cubic cleavage of galena; note how the cleavage surfaces show up as different but parallel layers in the crystal.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>To work with cleavage, it is important to remember that cleavage is a result of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a> separating along planes of atoms in the crystal structure. On some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, <strong>cleavage planes<\/strong> may be confused with crystal faces. This will usually not be an issue for crystals of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that grew together within rocks. The act of breaking the rock to expose a fresh face will most likely break the crystals along cleavage planes. Some cleavage planes are parallel with crystal faces but many are not.\u00a0Cleavage planes are smooth, flat, parallel planes within the crystal. The cleavage planes may show as parallel cracks that penetrate into the crystal (see <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a> below), or show on the edge or side of the crystal as a series of steps like rice terraces. For some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> characteristic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a> is to grow crystal faces even when surrounded by other crystals in rock. An example is garnet. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> grown freely where the crystals are unconstrained and can take characteristic shapes often form crystal faces (see <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a> below).<\/p>\n<figure id=\"attachment_2829\" aria-describedby=\"caption-attachment-2829\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Quartz-crystals.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2829\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Quartz-crystals-300x284-1.jpg\" alt=\"Freely grown quartz crystals showing crysatl faces\" width=\"300\" height=\"284\" \/><\/a><figcaption id=\"caption-attachment-2829\" class=\"wp-caption-text\">Freely growing quartz crystals showing crystal faces<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\">In some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, distinguishing cleavage planes from crystal faces may be challenging for the student. Understanding the nature of cleavage and referring to the number of cleavage planes and cleavage angles on identification keys should provide the student with enough information to distinguish cleavages from crystal faces. Cleavage planes may show as multiple parallel cracks or flat surfaces on the crystal. Cleavage planes may be expressed as a series of steps like terraced rice paddies. See the cleavage surfaces on galena above or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a> below. Cleavage planes arise from the tendency of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> crystals to break along specific planes of weakness within the crystal favored by atomic arrangements. The number of cleavage planes, the quality of the cleavage surfaces, and the angles between them are diagnostic for many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> and cleavage is one of the most useful properties for identifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. Learning to recognize cleavage is an especially important and useful skill in studying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>.<\/span><\/p>\n<figure id=\"attachment_2830\" aria-describedby=\"caption-attachment-2830\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.61_Cleavage_steps_in_wollastonite.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2830\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.61_Cleavage_steps_in_wollastonite-300x224-1.jpg\" alt=\"Image of wollastonite, a crystal showing step-like cleavage on one side. All steps are along the same direction of cleavage.\" width=\"300\" height=\"224\" \/><\/a><figcaption id=\"caption-attachment-2830\" class=\"wp-caption-text\">Steps of cleavage along the same cleavage direction<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2831\" aria-describedby=\"caption-attachment-2831\" style=\"width: 220px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.63_cleavage_in_Amphibole.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2831\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.63_cleavage_in_Amphibole-295x300-1.jpg\" alt=\"Photomicrograph showing 120\/60 degree cleavage in amphibole\" width=\"220\" height=\"224\" \/><\/a><figcaption id=\"caption-attachment-2831\" class=\"wp-caption-text\">Photomicrograph showing 120\/60 degree cleavage within a grain of amphibole<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>As an identification property of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, cleavage is usually given in terms of the quality of the cleavage (perfect, imperfect, or none), the number of cleavage surfaces, and the angles between the surfaces.\u00a0The most common number of cleavage plane directions in the common rock-forming <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are: one perfect cleavage (as in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">mica<\/a>), two cleavage planes (as in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a>), and three cleavage planes (as in halite, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a>, and galena). One perfect cleavage (as in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">mica<\/a>) develops on the top and bottom of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> specimen with many parallel cracks showing on the sides but no angle of intersection. Two cleavage planes intersect at an angle. Common cleavage angles are 60\u00b0, 75\u00b0, 90\u00b0, and 120\u00b0.\u00a0 <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">Amphibole<\/a> has two cleavage planes at\u00a060\u00b0 and\u00a0120\u00b0. Galena and halite have three cleavage planes at 90\u00b0 (cubic cleavage). <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">Calcite<\/a> cleaves readily in three directions producing a cleavage figure called a rhomb that looks like a cube squashed over toward one corner giving rise to the approximately 75\u00b0 cleavage angles. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">Pyroxene<\/a> has an imperfect cleavage with two planes at 90\u00b0.<\/p>\n<p><strong>Cleavages on common rock-forming <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a><\/strong><\/p>\n<ul>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">Quartz<\/a>\u2014none (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_987\">conchoidal<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a>)<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1789\">Olivine<\/a>\u2014none (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_987\">conchoidal<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a>)<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">Mica<\/a>\u20141 perfect<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">Feldspar<\/a>\u20142 perfect at 90\u00b0<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">Pyroxene<\/a>\u20142 imperfect at 90\u00b0<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">Amphibole<\/a>\u20142 perfect at 60\u00b0\/120\u00b0<\/li>\n<li><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">Calcite<\/a>\u20143 perfect at approximately 75\u00b0<\/li>\n<li>Halite, galena, pyrite\u20143 perfect at 90\u00b0<\/li>\n<\/ul>\n<h3><b>3.5.6 Special Properties <\/b><\/h3>\n<figure id=\"attachment_2832\" aria-describedby=\"caption-attachment-2832\" style=\"width: 150px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ulexit_Fernsehstein.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-2832\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ulexit_Fernsehstein-150x150-1.jpg\" alt=\"The words on the page are projected upwards onto the mineral\" width=\"150\" height=\"150\" \/><\/a><figcaption id=\"caption-attachment-2832\" class=\"wp-caption-text\">A demonstration of ulexite&rsquo;s image projection<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\">Special properties are unique and identifiable characteristics used to identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> or that allow some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> to be used for special purposes.\u00a0<\/span>Ulexite has a fiber-optic property that can project images through the crystal like a high-definition television screen (see figure). A simple identifying special property is taste, such as the salty flavor of halite or common table salt (NaCl). Sylvite is potassium chloride (KCl) and has a more bitter taste.<\/p>\n<figure id=\"attachment_2833\" aria-describedby=\"caption-attachment-2833\" style=\"width: 225px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Latrobe_gold_nugget_Natural_History_Museum.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2833\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Latrobe_gold_nugget_Natural_History_Museum-225x300-1.jpg\" alt=\"The nugget is gold\" width=\"225\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2833\" class=\"wp-caption-text\">Native gold has one of the highest specific gravities.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Another property geologists may use to identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> is a property related to density called <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_989\">specific gravity<\/a><\/strong>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_989\">Specific gravity<\/a> measures the weight of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> specimen relative to the weight of an equal volume of water. The value is expressed as a ratio between the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> and water weights. To measure <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_989\">specific gravity<\/a>, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> specimen is first weighed in grams then submerged in a graduated cylinder filled with pure water at room <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a>. The rise in water level is noted using the cylinder\u2019s graduated scale. Since the weight of water at room <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> is 1 gram per cubic centimeter, the ratio of the two weight numbers gives the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_989\">specific gravity<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_989\">Specific gravity<\/a> is easy to measure in the laboratory but is less useful for <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> identification in the field than other more easily observed properties, except in a few rare cases such as the very dense galena or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a> gold. The high density of these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> gives rise to a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1725\">qualitative<\/a> property called \u201cheft.\u201d Experienced geologists can roughly assess <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_989\">specific gravity<\/a> by heft, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1723\">subjective<\/a> quality of how heavy the specimen feels in one\u2019s hand relative to its size.<\/p>\n<p>A simple test for identifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> and dolomite is to drop a bit of dilute hydrochloric acid (10-15% HCl) on the specimen. If the acid drop effervesces or fizzes on the surface of the rock, the specimen is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a>. If it does not, the specimen is scratched to produce a small amount of powder and test with acid again. If the acid drop fizzes slowly on the powdered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>, the specimen is dolomite. The difference between these two <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> can be seen in the video. Geologists who work with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> rocks carry a small dropper bottle of dilute HCl in their field kit. Vinegar, which contains acetic acid, can be used for this test and is used to distinguish non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a> from limestone. While acidic, vinegar produces less of a fizzing reaction because acetic acid is a weaker acid.<\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"Calcite and Dolomite Reacting with Hydrochloric Acid\" width=\"500\" height=\"375\" src=\"https:\/\/www.youtube.com\/embed\/DX6ZMPbA09U?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<figure id=\"attachment_3750\" aria-describedby=\"caption-attachment-3750\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Calcite-and-Dolomite-YouTube-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-228\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-150x150.png 150w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-300x300.png 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-1024x1024.png 1024w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-768x768.png 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-65x65.png 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-225x225.png 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code-350x350.png 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Calcite-and-Dolomite-YouTube-QR-Code.png 1155w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3750\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this YouTube video via this QR Code.<\/figcaption><\/figure>\n<figure id=\"attachment_2834\" aria-describedby=\"caption-attachment-2834\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Magnetite_Lodestone.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2834\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Magnetite_Lodestone-300x200-1.jpg\" alt=\"The paperclip is sticking up into the air.\" width=\"300\" height=\"200\" \/><\/a><figcaption id=\"caption-attachment-2834\" class=\"wp-caption-text\">Paperclips attach to lodestone (magnetite).<\/figcaption><\/figure>\n<p>Some iron-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are magnetic and are attracted to magnets. A common name for a naturally magnetic iron <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a> is <strong>lodestone<\/strong>. Others include magnetite (Fe3O<sub>4<\/sub>) and ilmenite (FeTiO<sub>3<\/sub>). Magnetite is strongly attracted to magnets and can be magnetized. Ilmenite and some types of hematite are weakly magnetic.<\/p>\n<figure id=\"attachment_2825\" aria-describedby=\"caption-attachment-2825\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.65_Striations_in_plagioclase.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-2825 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.65_Striations_in_plagioclase-300x242-1.jpg\" alt=\"Striations or parallel dark lines on one cleavage surface on plagioclase feldspar\" width=\"300\" height=\"242\" \/><\/a><figcaption id=\"caption-attachment-2825\" class=\"wp-caption-text\">Iridescence on plagioclase; also showing striations on the cleavage surface<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> and mineraloids scatter light via a phenomenon called <strong>iridescence<\/strong>. This property occurs in labradorite (a variety of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a>) and opal. It is also seen in biologically created substances like pearls and seashells. Cut diamonds show iridescence and the jeweler\u2019s diamond cut is designed to maximize this property.<\/span><\/p>\n<figure id=\"attachment_2835\" aria-describedby=\"caption-attachment-2835\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.66_exsolution-_lamellae_perthitic_feldspar_Dan_Patch_SD.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2835\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.66_exsolution-_lamellae_perthitic_feldspar_Dan_Patch_SD-300x217-1.jpg\" alt=\"Image showing exsolution lamellae in potassium feldspar. These are separations of sodium feldspar from potassium feldspar within the crystal, not striations.\" width=\"300\" height=\"217\" \/><\/a><figcaption id=\"caption-attachment-2835\" class=\"wp-caption-text\">Exsolution lamellae within potassium feldspar<\/figcaption><\/figure>\n<p><strong>Striations<\/strong> on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> cleavage faces are an optical property that can be used to separate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> from potassium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">K-spar<\/a>). A process called twinning creates parallel zones in the crystal that are repeating mirror images. The actual cleavage angle in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a> is slightly different than 90<sup>o<\/sup> and the alternating mirror images in these twinned zones produce a series of parallel lines on one of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">plagioclase<\/a>\u2019s two cleavage faces. Light reflects off these twinned lines at slightly different angles which then appear as light and dark lines called striations on the cleavage surface.\u00a0Potassium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> does not exhibit twinning or striations but may show linear features called <strong>exsolution lamellae<\/strong>, also known as perthitic lineation or simply perthite. Because sodium and potassium do not fit into the same <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> crystal structure, the lines are created by small amounts of sodium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> (albite) separating from the dominant potassium <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a> (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">K-spar<\/a>) within the crystal structure. The two different <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspars<\/a> crystallize out into roughly parallel zones within the crystal, which are seen as these linear markings.<\/p>\n<figure id=\"attachment_2793\" aria-describedby=\"caption-attachment-2793\" style=\"width: 244px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/03.35_FluoriteUV-scaled.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"size-medium wp-image-2793\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/03.35_FluoriteUV-244x300-1.jpg\" alt=\"Purplish crystals of fluorite. The second image shows the deep blue fluorescence of fluorite under ultraviolet light.\" width=\"244\" height=\"300\" \/><\/a><figcaption id=\"caption-attachment-2793\" class=\"wp-caption-text\">Fluorite. B shows fluorescence of fluorite under UV light<\/figcaption><\/figure>\n<p>One of the most interesting special <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> properties is <strong>fluorescence<\/strong>. Certain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, or \u00a0trace <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> within them, give off visible light when exposed to ultraviolet radiation or black light. Many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> exhibits have a fluorescence room equipped with black lights so this property can be observed. An even rarer optical property is phosphorescence. <strong>Phosphorescent<\/strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> absorb light and then slowly release it, much like a glow-in-the-dark sticker.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<h3><\/h3>\n<h3><\/h3>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-21\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-21\" class=\"h5p-iframe\" data-content-id=\"21\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"3.5 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3749\" aria-describedby=\"caption-attachment-3749\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/3.5-Did-I-Get-It-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-231\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-150x150.png 150w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-300x300.png 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-1024x1024.png 1024w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-768x768.png 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-65x65.png 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-225x225.png 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code-350x350.png 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/3.5-Did-I-Get-It-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3749\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 3.5 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-size: 18pt\"><strong>Summary<\/strong><\/span><\/h2>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> are the building blocks of rocks and essential to understanding geology. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Mineral<\/a> properties are determined by their atomic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bonds<\/a>. Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> begin in a fluid, and either crystallize out of cooling <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitate<\/a> as ions and molecules out of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1784\">saturated<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a> are largest group of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> on Earth, by number of varieties and relative quantity, making up a large portion of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>. Based on the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1788\">silicon-oxygen tetrahedra<\/a>, the crystal structure of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicates<\/a> reflects the fact that silicon and oxygen are the top two of Earth\u2019s most abundant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. Non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are also economically important, and providing many types of construction and manufacturing materials. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> are identified by their unique physical properties, including <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_977\">luster<\/a>, color, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_978\">streak<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_979\">hardness<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_980\">crystal habit<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a>, cleavage, and special properties.<\/p>\n<h3>Take this quiz to check your comprehension of this Chapter.<\/h3>\n<div id=\"h5p-22\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-22\" class=\"h5p-iframe\" data-content-id=\"22\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Chapter 3 Review\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3748\" aria-describedby=\"caption-attachment-3748\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ch.3-Review-QR-Code.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-thumbnail wp-image-232\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\" srcset=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-150x150.png 150w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-300x300.png 300w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-1024x1024.png 1024w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-768x768.png 768w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-65x65.png 65w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-225x225.png 225w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code-350x350.png 350w, https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.3-Review-QR-Code.png 1147w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/a><figcaption id=\"caption-attachment-3748\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the review quiz for Chapter 3 via this QR Code.<\/figcaption><\/figure>\n<h2><b>References<\/b><\/h2>\n<div class=\"csl-bib-body\">\n<ol>\n<li class=\"csl-entry\">Clarke, F.W.H.S.W., 1927, The Composition of the Earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">Crust<\/a>: Professional Paper, United States Geological Survey, Professional Paper.<\/li>\n<li class=\"csl-entry\">Gordon, L.M., and Joester, D., 2011, Nanoscale chemical tomography of buried organic-inorganic interfaces in the chiton tooth: Nature, v. 469, no. 7329, p. 194\u2013197.<\/li>\n<li class=\"csl-entry\">Hans Wedepohl, K., 1995, The composition of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental crust<\/a>: Geochim. Cosmochim. Acta, v. 59, no. 7, p. 1217\u20131232.<\/li>\n<li class=\"csl-entry\">Lambeck, K., 1986, Planetary evolution: banded iron formations: v. 320, no. 6063, p. 574\u2013574.<\/li>\n<li class=\"csl-entry\">metallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a> | chemistry.<\/li>\n<li class=\"csl-entry\">Scerri, E.R., 2007, The Periodic Table: Its Story and Its Significance: Oxford University Press, USA.<\/li>\n<li class=\"csl-entry\">Thomson, J.J., 1897, XL. Cathode Rays: Philosophical Magazine Series 5, v. 44, no. 269, p. 293\u2013316.<\/li>\n<li class=\"csl-entry\">Trenn, T.J., Geiger, H., Marsden, E., and Rutherford, E., 1974, The Geiger-Marsden Scattering Results and Rutherford\u2019s Atom, July 1912 to July 1913: The Shifting Significance of Scientific Evidence: Isis, v. 65, no. 1, p. 74\u201382.<\/li>\n<\/ol>\n<\/div>\n<p><span style=\"font-weight: 400\">\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div class=\"media-attributions clear\" prefix:cc=\"http:\/\/creativecommons.org\/ns#\" prefix:dc=\"http:\/\/purl.org\/dc\/terms\/\"><h2>Mention de la source du contenu multim\u00e9dia<\/h2><ul><li >H2O 2D labelled       <\/li><li >3.1 Did I Get It QR Code       <\/li><li >3.2 Did I Get It QR Code       <\/li><li >MicaSheetUSGOV       <\/li><li >3.3 Did I Get It QR Code       <\/li><li >3.4 Did I Get It QR Code       <\/li><li >Quartz Br\u00e9sil       <\/li><li >Peridot2       <\/li><li >Hanksite       <\/li><li >Calcite and Dolomite YouTube QR Code       <\/li><li >3.5 Did I Get It QR Code       <\/li><li >Ch.3 Review QR Code       <\/li><\/ul><\/div><div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">d\u00e9finition<\/span><template id=\"term_233_1765\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1765\"><div tabindex=\"-1\"><p>A rule that says the outer valence shell of electrons is complete when it contains 8 electrons.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1778\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1778\"><div tabindex=\"-1\"><p>[glossary]<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1781\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1781\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1788\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1788\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1787\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1787\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_971\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_971\"><div tabindex=\"-1\"><p>QR Code generated with QRCode Monkey. All generated QR Codes are 100% free and can be used for whatever you want. This includes all commercial purposes. <\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_973\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_973\"><div tabindex=\"-1\"><figure id=\"attachment_4617\" aria-describedby=\"caption-attachment-4617\" style=\"width: 768px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Latrobe_gold_nugget_Natural_History_Museum.jpg\"><img class=\"wp-image-929 size-full\" title=\"&quot;I,\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/02\/Latrobe_gold_nugget_Natural_History_Museum.jpg\" alt=\"The nugget has cube shapes.\" width=\"768\" height=\"1024\"><\/a><figcaption id=\"caption-attachment-4617\" class=\"wp-caption-text\">The Latrobe Gold Nugget, as seen on display in the London Natural History Museum, is 717 grams and displays the rare cubic form of native gold. Most gold, even larger nuggets, grow in confined spaces where the euhedral nature of the mineral is not seen.<\/figcaption><\/figure>\n<h1>16 Energy and Mineral Resources<\/h1>\n<p><b>KEY CONCEPTS<\/b><\/p>\n<ul>\n<li>Describe how a\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a>\u00a0resource is different from a\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>\u00a0resource.<\/li>\n<li>Compare the pros and cons of extracting and using fossil fuels and conventional and unconventional petroleum sources.<\/li>\n<li>Describe how metallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are formed\u00a0and extracted.<\/li>\n<li>Understand how society uses\u00a0nonmetallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0resources.<\/li>\n<\/ul>\n<figure id=\"attachment_4618\" aria-describedby=\"caption-attachment-4618\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.0_Stone-Tool.jpg\"><img class=\"wp-image-930 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.0_Stone-Tool-300x225.jpg\" alt=\"The rock has a smooth side and a sharp side.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4618\" class=\"wp-caption-text\">A Mode 1 Oldowan tool used for chopping<\/figcaption><\/figure>\n<p>This text has previously discussed geology\u2019s pioneers, such as scientists James Hutton and Charles Lyell, but the first real \u201cgeologists\u201d were the hominids who picked up stones and began the stone age. Maybe stones were first used as curiosity pieces, maybe as weapons, but ultimately, they were used as tools. This was the Paleolithic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">Period<\/a>, the beginning of geologic study, and it dates back 2.6 million years to east Africa.<\/p>\n<p>In modern times, geologic knowledge is important for locating economically valuable materials for society\u2019s use. In fact, all things we use come from only three sources: they are farmed, hunted or fished, or mined. At the turn of the twentieth century, speculation was rampant that food supplies would not keep pace with world demand, suggesting the need to develop artificial fertilizers. Sources of fertilizer ingredients are: nitrogen is processed from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a>, using the Haber process for the manufacture of ammonia from atmospheric nitrogen and hydrogen; potassium comes from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1744\">hydrosphere<\/a>, such as lakes or ocean evaporation; and phosphorus is mined from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>, such as minerals like apatite from phosphorite rock, which is found in Florida, North Carolina, Idaho, Utah, and around the world. \u00a0Thus, without mining and processing of natural materials, modern civilization would not exist. Indeed, geologists are essential in this process.<\/p>\n<h2><strong>16.1 Mining<\/strong><\/h2>\n<figure id=\"attachment_4619\" aria-describedby=\"caption-attachment-4619\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Simplified_world_mining_map_1.png\"><img class=\"wp-image-931 size-large\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Simplified_world_mining_map_1-1024x383.png\" alt=\"The map shows many different materials that are mined across the world.\" width=\"1024\" height=\"383\"><\/a><figcaption id=\"caption-attachment-4619\" class=\"wp-caption-text\">Map of world mining areas.<\/figcaption><\/figure>\n<p><strong>Mining<\/strong>\u00a0is defined as extracting valuable materials from the Earth for society\u2019s use. Usually, these include solid materials such as gold, iron,\u00a0coal, diamond, sand, and gravel, but materials can also include fluid resources such as\u00a0oil\u00a0and\u00a0natural gas. Modern\u00a0mining\u00a0has a long relationship with modern society. The oldest mine dates back 40,000 years to the Lion Cavern in Swaziland where there is evidence of\u00a0concentrated\u00a0digging\u00a0 into the Earth for hematite, an important iron ore used as red dye. Resources extracted by\u00a0mining\u00a0are generally considered to be\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>.<\/p>\n<h3><b>16.1.1. Renewable vs. nonrenewable resources<\/b><\/h3>\n<p>Resources generally come in two major categories:\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">Renewable<\/a> resources can be reused over and over or their availability replicated over a short human life span; <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources cannot.<\/p>\n<figure id=\"attachment_4621\" aria-describedby=\"caption-attachment-4621\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.1_Hoover_Dam_Colorado_River.jpg\"><img class=\"wp-image-932 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1_Hoover_Dam_Colorado_River-300x200.jpg\" alt=\"The dam has a large lake behind it\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4621\" class=\"wp-caption-text\">Hoover Dam provides hydroelectric energy and stores water for southern Nevada.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">Renewable<\/a><\/strong><strong>\u00a0resources<\/strong> are materials present in our environment that can be exploited and replenished. Some common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> energy sources are linked with green energy sources because they are associated with relatively small or easily remediated environmental impact. For example, solar energy comes from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1250\">fusion<\/a> within the Sun, which radiates electromagnetic energy. This energy reaches the Earth constantly and consistently and should continue to do so for about five billion more years. Wind energy, also related to solar energy, is maybe the oldest <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> energy and is used to sail ships and power windmills. Both solar and wind-generated energy are variable on Earth\u2019s surface. These limitations are offset because we can use energy storing devices, such as batteries or electricity exchanges between producing sites. The Earth\u2019s heat, known as geothermal energy, can be viable anywhere that geologists drill deeply enough. In practice, geothermal energy is more useful where heat flow is great, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> zones or regions with a thinner <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>. Hydroelectric dams provide energy by allowing water to fall through the dam under gravity, which activates turbines that produce the energy. Ocean tides are also a reliable energy source. All of these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> resources provide energy that powers society. Other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> resources are plant and animal matter, which are used for food, clothing, and other necessities, but are being researched as possible energy sources.<\/p>\n<figure id=\"attachment_4622\" aria-describedby=\"caption-attachment-4622\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Rough_diamond.jpg\"><img class=\"wp-image-933 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Rough_diamond-300x226.jpg\" alt=\"The diamond is clear and pyramidal.\" width=\"300\" height=\"226\"><\/a><figcaption id=\"caption-attachment-4622\" class=\"wp-caption-text\">Natural, octahedral shape of diamond.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">Nonrenewable<\/a><\/strong><strong>\u00a0resources<\/strong> cannot be replenished at a sustainable rate. They are finite within human time frames. Many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources come from planetary, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a>, or long-term biologic processes and include materials such as gold, lead, copper, diamonds, marble, sand, natural gas, oil, and coal. Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources include specific concentrated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> listed on the periodic table; some are compounds of those <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. For example, if society needs iron (Fe) sources, then an exploration geologist will search for iron-rich deposits that can be economically extracted. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">Nonrenewable<\/a> resources may be abandoned when other materials become cheaper or serve a better purpose. For example, coal is abundantly available in England and other nations, but because oil and natural gas are available at a lower cost and lower environmental impact, coal use has decreased. Economic competition among <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources is shifting use away from coal in many developed countries.<\/p>\n<h3><b>16.1.2. Ore<\/b><\/h3>\n<figure id=\"attachment_4623\" aria-describedby=\"caption-attachment-4623\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/MichiganBIF.jpg\"><img class=\"wp-image-934 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MichiganBIF-300x206.jpg\" alt=\"The rock shows red and brown layering.\" width=\"300\" height=\"206\"><\/a><figcaption id=\"caption-attachment-4623\" class=\"wp-caption-text\">Banded-iron formations are an important ore of iron (Fe).<\/figcaption><\/figure>\n<p>Earth\u2019s materials include the\u00a0periodic table <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. However, it is rare that\u00a0these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> are concentrated\u00a0to the point where it is profitable to extract and process the material into usable products. Any place where a valuable material is\u00a0concentrated\u00a0is a geologic and geochemical\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_765\">anomaly<\/a>. A body of material from which one or more valuable substances can be\u00a0mined\u00a0at a profit, is called an\u00a0<strong>ore<\/strong>\u00a0deposit. Typically, the term\u00a0ore\u00a0is used for only metal-bearing\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, but it can be applied to valuable <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>\u00a0resource concentrations such as fossil fuels, building stones, and other nonmetal deposits, even\u00a0groundwater. If a metal-bearing resource is not profitable to mine, it is referred to as a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> deposit. The term <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1738\">natural resource<\/a><\/strong> is more common than\u00a0the term ore\u00a0for non-metal-bearing materials.<\/p>\n<figure id=\"attachment_4624\" aria-describedby=\"caption-attachment-4624\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16-Reserve-vs-Resource.jpg\"><img class=\"wp-image-935 size-medium\" style=\"font-weight: bold;background-color: transparent;text-align: inherit\" title=\"Source: Chris Johnson\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16-Reserve-vs-Resource-300x233.jpg\" alt=\"Diagram shows the small box of &quot;reserves&quot; within a larger box of &quot;resources&quot;. There is also an &quot;inferred resources&quot; box that is slightly larger than &quot;proven reserves&quot; box and an &quot;undiscovered resources&quot; box slightly larger than the resources box.\" width=\"300\" height=\"233\"><\/a><figcaption id=\"caption-attachment-4624\" class=\"wp-caption-text\">Diagram illustrating the relative abundance of proven reserves, inferred reserves, resources, and undiscovered resources. (Source: Chris Johnson)<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\">It is implicit that the technology to mine is available, economic conditions are suitable, and political, social and environmental considerations are satisfied in order to classify a\u00a0 <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1738\">natural resource<\/a> deposit as ore. \u00a0Depending on the substance, it can be concentrated in a narrow vein or distributed over a large area as a low-concentration ore. Some materials are mined directly from bodies of water (e.g. sylvite for potassium; water through desalination) and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a> (e.g. nitrogen for fertilizers). \u00a0These differences lead to various methods of mining, and differences in terminology depending on the certainty. <strong>Ore m<\/strong><\/span><b>ineral resource<\/b><span style=\"font-weight: 400\"> is used for an indication of ore that is potentially extractable, and the term <strong>ore\u00a0<\/strong><\/span><b><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> reserve<\/b><span style=\"font-weight: 400\"> is used for a well defined (proven), profitable amount of extractable ore.<\/span><\/p>\n<figure id=\"attachment_4625\" aria-describedby=\"caption-attachment-4625\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/McKelveyDiagram.jpg\"><img class=\"wp-image-936 size-large\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/McKelveyDiagram-1024x596.jpg\" alt=\"The chart shows reserves vs. resources\" width=\"1024\" height=\"596\"><\/a><figcaption id=\"caption-attachment-4625\" class=\"wp-caption-text\">McKelvey diagram showing different definitions for different degrees of concentration and understanding of mineral deposits.<\/figcaption><\/figure>\n<h3><b>16.1.3. Mining Techniques<\/b><\/h3>\n<p>The mining style is determined by technology, social license, and economics. It is in the best interest of the company extracting the resources to do so in a cost-effective way. Fluid resources, such as\u00a0oil\u00a0and gas, are extracted by drilling wells and pumping. Over the years, drilling has evolved into a complex discipline in which directional drilling can produce multiple bifurcations and curves originating from a single drill collar at the surface. Using geophysical tools like\u00a0seismic\u00a0imaging, geologists can pinpoint resources and extract efficiently.<\/p>\n<p>Solid resources are extracted by two\u00a0principal methods of which there are many variants.\u00a0<strong>Surface mining<\/strong>\u00a0is used to remove material from the outermost part\u00a0of the Earth.\u00a0<strong>Open pit<\/strong>\u00a0<strong>mining<\/strong>\u00a0is used to target shallow, broadly disseminated resources.<\/p>\n<figure id=\"attachment_4626\" aria-describedby=\"caption-attachment-4626\" style=\"width: 352px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Bingham_Canyon_mine_2016.jpg\"><img class=\"wp-image-4626\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bingham_Canyon_mine_2016-1.jpg\" alt=\"The image is a large hole in a mountainside.\" width=\"352\" height=\"212\"><\/a><figcaption id=\"caption-attachment-4626\" class=\"wp-caption-text\">Bingham Canyon Mine, Utah. This open pit mine is the largest man-made removal of rock in the world.<\/figcaption><\/figure>\n<p>Open pit mining requires careful study of the ore body through surface mapping and drilling exploratory cores. The pit is progressively deepened through additional mining cuts to extract the ore. Typically, the pit\u2019s walls are as steep as can be safely managed. Once the pit is deepened, widening the top is very expensive. A steep wall is thus an engineering balance between efficient and profitable mining (from the company's point of view) and mass wasting (angle of repose from a safety p0int of view) so that there is less waste to remove. The waste is called non-valuable rock or overburden and moving it is costly. Occasionally, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_246\">landslides<\/a> do occur, such as the very large <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_246\">landslide<\/a> in the Kennecott Bingham Canyon mine, Utah, in 2013. These events are costly and dangerous. The job of engineering geologists is to carefully monitor the mine; when company management heeds their warnings, there is ample time and action to avoid or prepare for any slide.<\/p>\n<figure id=\"attachment_4627\" aria-describedby=\"caption-attachment-4627\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Coal_mine_Wyoming.jpg\"><img class=\"size-medium wp-image-938\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Coal_mine_Wyoming-300x200.jpg\" alt=\"A large machine is removing coal.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4627\" class=\"wp-caption-text\">A surface coal mine in Wyoming.<\/figcaption><\/figure>\n<p><strong>Strip mining<\/strong>\u00a0and\u00a0<strong>mountaintop mining<\/strong>\u00a0are\u00a0surface mining\u00a0techniques that are used to mine resources that cover large areas, especially layered resources, such as coal. In this method, an entire mountaintop or rock layer is removed to access the\u00a0ore\u00a0below. Surface mining\u2019s\u00a0environmental impacts are usually much greater due to the large surface footprint that\u2019s disturbed.<\/p>\n<figure id=\"attachment_4628\" aria-describedby=\"caption-attachment-4628\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/UndergroundOilShaleEstonia.jpg\"><img class=\"size-medium wp-image-939\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/UndergroundOilShaleEstonia-300x193.jpg\" alt=\"A large truck is loading material underground.\" width=\"300\" height=\"193\"><\/a><figcaption id=\"caption-attachment-4628\" class=\"wp-caption-text\">Underground mining in Estonia of Oil Shale.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><strong>Underground mining<\/strong>\u00a0is a method often used to mine higher-grade, more localized, or very\u00a0concentrated\u00a0resources. For one example, geologists mine some\u00a0underground ore\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0by introducing chemical agents, which dissolve\u00a0the target\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>.\u00a0Then, they bring the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a> to the surface where\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> extracts the material. But more often, a\u00a0mining\u00a0shaft tunnel or a large network of these shafts and tunnels is dug to access the material. The decision to mine underground or from Earth\u2019s surface is dictated by\u00a0the ore\u00a0deposit\u2019s concentration, depth, geometry, land-use policies, economics, surrounding rock strength, and physical access to the\u00a0ore. For example, to use surface mining techniques for deeper deposits might require removing too much material, or the necessary method may be too dangerous or impractical, or removing the entire overburden may be too expensive, or the\u00a0mining\u00a0footprint would be too large. These factors may prevent geologists from surface mining\u00a0materials and cause a project to be\u00a0mined\u00a0underground. The mining method\u00a0and its feasibility depends on the commodity\u2019s price and the cost of the technology needed to remove it and deliver it to market.\u00a0Thus,\u00a0mines\u00a0and the towns that support them come and go as the commodity price varies.\u00a0And, conversely, technological advances and market demands may reopen\u00a0mines\u00a0and revive ghost towns.<\/p>\n<h3><b>16.1.4. Concentrating and Refining<\/b><\/h3>\n<figure id=\"attachment_4629\" aria-describedby=\"caption-attachment-4629\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.1_phosphate_smelting_furnace.jpg\"><img class=\"wp-image-940 size-medium\" title=\"&quot;Alfred\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1_phosphate_smelting_furnace-300x233.jpg\" alt=\"A man is operating a large machine that looks like a blast furnace.\" width=\"300\" height=\"233\"><\/a><figcaption id=\"caption-attachment-4629\" class=\"wp-caption-text\">A phosphate smelting operation in Alabama, 1942.<\/figcaption><\/figure>\n<p>All\u00a0ore\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0occur mixed with less desirable components called\u00a0<strong>gangue<\/strong>. The process of physically separating\u00a0gangue\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0from\u00a0ore bearing\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0is called\u00a0<strong>concentrating<\/strong>. Separating a desired\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>\u00a0from a host\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0by chemical means, including heating, is called\u00a0<strong>smelting<\/strong>. \u00a0Finally, taking a metal such as copper and removing other trace metals such as gold or silver is done through the <strong>refining<\/strong> process. Typically, <strong>refining<\/strong> is done one of three ways: 1. Materials can either be mechanically separated and processed based on the ore\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u2019s unique physical properties, such as recovering placer\u00a0gold based on its high density. 2. Materials can be heated to chemically separate desired components, such as refining\u00a0crude\u00a0oil\u00a0into\u00a0gasoline. 3. Materials can be smelted, in which controlled chemical reactions unbind metals from the\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0they are contained in, such as when copper is taken out of chalcopyrite (CuFeS<sub>2<\/sub>).\u00a0Mining,\u00a0concentrating,\u00a0smelting,\u00a0and\u00a0refining\u00a0processes require enormous energy. Continual advances in metallurgy- and\u00a0mining-practice strive to develop ever more energy efficient and environmentally benign processes and practices.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-109\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-109\" class=\"h5p-iframe\" data-content-id=\"109\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"16.3 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_4901\" aria-describedby=\"caption-attachment-4901\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/16.1-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-941\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-4901\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 16.1 via this QR Code.<\/figcaption><\/figure>\n<h2><strong>16.2. Fossil Fuels<\/strong><\/h2>\n<figure id=\"attachment_4630\" aria-describedby=\"caption-attachment-4630\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.2_Castle_Gate_Power_Plant_Utah_2007.jpg\"><img class=\"wp-image-942 size-medium\" title=\"&quot;<a\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.2_Castle_Gate_Power_Plant_Utah_2007-300x188.jpg\" alt=\"The power plant has smoke coming from it\" width=\"300\" height=\"188\"><\/a><figcaption id=\"caption-attachment-4630\" class=\"wp-caption-text\">Coal power plant in Helper, Utah.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">Fossils<\/a><\/strong><strong>\u00a0fuels<\/strong> are extractable sources of stored energy that were created by ancient ecosystems. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1738\">natural resources<\/a> that typically fall under this category are coal, oil, petroleum, and natural gas. These resources were originally formed via photosynthesis by living organisms such as plants, phytoplankton, algae, and cyanobacteria. This energy is actually <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossil<\/a> solar energy, since the sun\u2019s ancient energy was converted by ancient organisms into tissues that preserved the chemical energy within the fossil fuel. Of course, as the energy is used, just like photosynthetic respiration that occurs today, carbon enters the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a> as CO<sub>2<\/sub>, causing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> consequences (see <a href=\"https:\/\/opengeology.org\/textbook\/15-global-climate-change\/\">Chapter 15<\/a>).\u00a0Today humanity uses fossil fuels\u00a0for most of the world\u2019s energy.<\/p>\n<figure id=\"attachment_4631\" aria-describedby=\"caption-attachment-4631\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Coral_Outcrop_Flynn_Reef.jpg\"><img class=\"wp-image-4631 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Coral_Outcrop_Flynn_Reef-2.jpg\" alt=\"The reef has many intricacies.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4631\" class=\"wp-caption-text\">Modern coral reefs and other highly-productive shallow marine environments are thought to be the sources of most petroleum resources.<\/figcaption><\/figure>\n<p>Converting solar energy by living organisms into hydrocarbon fossil fuels is a complex process. As organisms die, they decompose slowly, usually due to being buried rapidly, and the chemical energy stored within the organisms\u2019 tissues is buried within surrounding geologic materials. All fossil\u00a0fuels contain carbon that was produced in an ancient environment. In environments rich with organic matter such as swamps, coral reefs, and planktonic blooms, there is a higher potential for fossil fuels to accumulate. Indeed, there is some evidence that over geologic time, organic hydrocarbon fossil fuel material was highly produced globally. Lack of oxygen and moderate temperatures in the environment seem to help preserve these organic substances. Also, the heat and pressure applied to organic material after it is buried contribute to transforming it into higher quality materials, such as brown coal to anthracite and oil to gas. Heat and pressure can also cause mobile materials to migrate to conditions suitable for extraction.<\/p>\n<h3><b>16.2.1. Fossil Fuels<\/b><\/h3>\n<h4><span style=\"font-weight: 400\">OIL AND GAS<\/span><\/h4>\n<figure id=\"attachment_4632\" aria-describedby=\"caption-attachment-4632\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Oil_Reserves.png\"><img class=\"wp-image-944 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Oil_Reserves-300x136.png\" alt=\"Darker countries are higher in oil\" width=\"300\" height=\"136\"><\/a><figcaption id=\"caption-attachment-4632\" class=\"wp-caption-text\">World Oil Reserves in 2013. Scale in billions of barrels.<\/figcaption><\/figure>\n<p><strong>P<\/strong>etroleum is principally derived from organic-rich shallow\u00a0marine\u00a0sedimentary deposits where the remains of micro-organisms like plankton accumulated in fine grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>. Petroleum\u2019s liquid component is called\u00a0<strong>oil,<\/strong>\u00a0and its gas component is called\u00a0<strong>natural gas<\/strong>, which is mostly made up of methane (CH<sub>4<\/sub>). As rocks such as shale, mudstone, or limestone lithify, increasing pressure and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> cause the oil and gas to be squeezed out and migrate from the <strong>source rock<\/strong> to a different rock unit higher in the rock column. Similar to the discussion of good\u00a0aquifers\u00a0in\u00a0<a href=\"https:\/\/opengeology.org\/textbook\/11-water\/\">Chapter 11<\/a>, if that rock is a sandstone, limestone, or other porous and permeable rock, and involved in a suitable stratigraphic or structural trapping process, then that rock can act as an<strong>\u00a0<\/strong>oil\u00a0and gas<strong> reservoir<\/strong>.<\/p>\n<figure id=\"attachment_4633\" aria-describedby=\"caption-attachment-4633\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Structural_Trap_Anticlinal.svg_.png\"><img class=\"wp-image-945 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Structural_Trap_Anticlinal.svg_-300x194.png\" alt=\"The rock layers are folded, and the petroleum is pooling toward the top of the fold.\" width=\"300\" height=\"194\"><\/a><figcaption id=\"caption-attachment-4633\" class=\"wp-caption-text\">A structural or anticline trap. The red on the image represents pooling petroleum. The green layer would be a permeable rock, and the yellow would be a reservoir rock.<\/figcaption><\/figure>\n<p>A\u00a0<strong>trap<\/strong> is a combination of a subsurface geologic structure, a porous and permeable rock, and an impervious layer that helps block oil and gas from moving further, which concentrates it for humans to extract later. A trap develops due to many different geologic situations. Examples include an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_504\">anticline<\/a> or domal structure, an impermeable salt <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_507\">dome<\/a>, or a fault bounded stratigraphic block, which is porous rock next to nonporous rock. The different traps have one thing in common: they pool fluid fossil fuels into a configuration in which extracting it is more likely to be profitable. Oil or gas in strata outside of a trap renders it less viable to extract.<\/p>\n<figure id=\"attachment_4634\" aria-describedby=\"caption-attachment-4634\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/TransgressionRegression.png\"><img class=\"wp-image-946 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/TransgressionRegression-300x199.png\" alt=\"Onlap is sediments moving toward the land. Offlap is moving away.\" width=\"300\" height=\"199\"><\/a><figcaption id=\"caption-attachment-4634\" class=\"wp-caption-text\">The rising sea levels of transgressions create onlapping sediments, regressions create offlapping.<\/figcaption><\/figure>\n<p><strong>Sequence stratigraphy<\/strong> is a branch of geology that studies sedimentary facies both horizontally and vertically and is devoted to understanding how sea level changes create organic-rich shallow marine muds, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonates<\/a>, and sands in areas that are close to each other. For example, shoreline environments may have beaches, lagoons, reefs, nearshore and offshore deposits, all next to each other. Beach sand, lagoonal and nearshore muds, and coral reef layers accumulate into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> that include sandstones\u2014good reservoir rocks\u2014 next to mudstones, next to limestones, both of which are potential source rocks. As sea level either rises or falls, the shoreline\u2019s location changes, and the sand, mud, and reef locations shift with it (see the figure). This places oil and gas producing rocks, such as mudstones and limestones next to oil and gas reservoirs, such as sandstones and some limestones. Understanding how the lithology and the facies\/stratigraphic relationships interplay is very important in finding new petroleum resources. Using sequence stratigraphy as a model allows geologists to predict favorable locations of the source rock and reservoir.<\/p>\n<h4><span style=\"font-weight: 400\">Tar Sands<\/span><\/h4>\n<figure id=\"attachment_4635\" aria-describedby=\"caption-attachment-4635\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Tar_Sandstone_California.jpg\"><img class=\"wp-image-947 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tar_Sandstone_California-300x286.jpg\" alt=\"The sandstone is black with tar.\" width=\"300\" height=\"286\"><\/a><figcaption id=\"caption-attachment-4635\" class=\"wp-caption-text\">Tar sandstone from the Miocene Monterrey Formation of California.<\/figcaption><\/figure>\n<p><strong>Conventional<\/strong>\u00a0oil\u00a0and gas, which is pumped from a\u00a0reservoir, is not the only way to obtain hydrocarbons. There are a few fuel sources known as <strong>unconventional<\/strong>\u00a0petroleum\u00a0sources. However, they are becoming more important as conventional sources become scarce.\u00a0<strong>Tar sands<\/strong>, or oil sands, are sandstones that contain petroleum products that are highly viscous, like tar, and thus cannot be drilled and pumped out of the ground readily like conventional oil. This unconventional fossil fuel is <strong>bitumen<\/strong>, which can be pumped as a fluid only at very low recovery rates and only when heated or mixed with solvents. So, using steam and solvent injections or directly mining tar sands to process later are ways to extract the tar from the sands. Alberta, Canada is known to have the largest tar sand reserves in the world. Note: as with ores, an energy resource becomes uneconomic if the total extraction and processing costs exceed the extracted material\u2019s sales revenue. Environmental costs may also contribute to a resource becoming uneconomic.<\/p>\n<h4><span style=\"font-weight: 400\">Oil Shale<\/span><\/h4>\n<figure id=\"attachment_4636\" aria-describedby=\"caption-attachment-4636\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Production_of_oil_shale.png\"><img class=\"wp-image-948 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Production_of_oil_shale-300x195.png\" alt=\"Oil shale has dramatically increased starting around 1945.\" width=\"300\" height=\"195\"><\/a><figcaption id=\"caption-attachment-4636\" class=\"wp-caption-text\">Global production of Oil Shale, 1880-2010.<\/figcaption><\/figure>\n<p><strong>Oil shale<\/strong>, or\u00a0tight oil, is a fine-grained\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1761\">sedimentary rock<\/a>\u00a0that has significant petroleum\u00a0or\u00a0natural gas quantities locked tightly in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediment<\/a>.\u00a0Shale\u00a0has high\u00a0porosity\u00a0but very low permeability and is a common fossil fuel source rock. To extract the\u00a0oil directly from the shale, the material has to be\u00a0mined\u00a0and heated, which, like with tar sands, is expensive and typically has a negative environmental impact.<\/p>\n<h4><span style=\"font-weight: 400\">Fracking<\/span><\/h4>\n<figure id=\"attachment_4637\" aria-describedby=\"caption-attachment-4637\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/HydroFrac2.svg_.png\"><img class=\"wp-image-949 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/HydroFrac2.svg_-300x175.png\" alt=\"The image shows fracking fluids cracking the rock, allowing methane to escape.\" width=\"300\" height=\"175\"><\/a><figcaption id=\"caption-attachment-4637\" class=\"wp-caption-text\">Schematic diagram of fracking.<\/figcaption><\/figure>\n<p>Another process used to extract the\u00a0oil\u00a0and gas from\u00a0shale\u00a0and other unconventional tight resources is called\u00a0<strong>hydraulic fracturing<\/strong>, better known as\u00a0<strong>fracking<\/strong>. In this method, high-pressure water, sand grains, and added chemicals are injected and pumped underground. Under high pressure, this creates and holds open\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fractures<\/a>\u00a0in the rocks, which help release the hard-to-access mostly\u00a0natural gas fluids. Fracking is more useful in tighter\u00a0sediments, especially\u00a0shale, which has a high\u00a0porosity\u00a0to store the hydrocarbons but low permeability to allow transmission of the hydrocarbons.\u00a0Fracking\u00a0has become controversial because its methods contaminate groundwater\u00a0and\u00a0induce seismic activity. This has created much controversy between public concerns, political concerns, and energy value.<\/p>\n<h3><b>16.2.2. Coal<\/b><\/h3>\n<figure id=\"attachment_4638\" aria-describedby=\"caption-attachment-4638\" style=\"width: 240px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Coal_Rank_USGS.png\"><img class=\"wp-image-950 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Coal_Rank_USGS-240x300.png\" alt=\"The chart shows many different coal rankings\" width=\"240\" height=\"300\"><\/a><figcaption id=\"caption-attachment-4638\" class=\"wp-caption-text\">USGS diagram of different coal rankings.<\/figcaption><\/figure>\n<p><strong>Coal<\/strong>\u00a0comes from fossilized swamps, though some older\u00a0coal\u00a0deposits that predate\u00a0terrestrial\u00a0plants are presumed to come from algal buildups. Coal is chiefly carbon, hydrogen, nitrogen, sulfur, and oxygen, with minor amounts of other\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. As plant material is incorporated into\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>, heat and pressure cause several changes that concentrate the fixed carbon, which is the coal\u2019s combustible portion. So, the more heat and pressure that\u00a0coal\u00a0undergoes, the greater is its carbon concentration and fuel value and the more desirable is the\u00a0coal.<\/p>\n<p>This is the general sequence of a swamp progressing through the various stages of coal formation and becoming more concentrated in carbon: Swamp =&gt; Peat =&gt; Lignite =&gt; Sub-bituminous =&gt; Bituminous =&gt; Anthracite =&gt; Graphite. As swamp materials collect on the swamp floor and are buried under accumulating materials, they first turn to peat.<\/p>\n<figure id=\"attachment_4639\" aria-describedby=\"caption-attachment-4639\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Peat_49302157252.jpg\"><img class=\"size-medium wp-image-951\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peat_49302157252-300x225.jpg\" alt=\"A lump of peat.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4639\" class=\"wp-caption-text\">Peat (also known as turf) consists of partially decayed organic matter. The Irish have long mined peat to be burned as fuel though this practice is now discouraged for environmental reasons.<\/figcaption><\/figure>\n<p>Peat itself is an economic fuel in some locations like the British Isles and Scandinavia. As <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1760\">lithification<\/a> occurs, peat turns to lignite. With increasing heat and pressure, lignite turns to sub-bituminous coal, bituminous coal, and then, in a process like metamorphism, anthracite. Anthracite is the highest metamorphic grade and most desirable coal since it provides the highest energy output. With even more heat and pressure driving out all the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1684\">volatiles<\/a> and leaving pure carbon, anthracite can become graphite.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_4640\" aria-describedby=\"caption-attachment-4640\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Coal_anthracite.jpg\"><img class=\"wp-image-4640 size-medium\" title=\"&quot;USGS\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Coal_anthracite-1.jpg\" alt=\"It is very black and shiny.\" width=\"300\" height=\"281\"><\/a><figcaption id=\"caption-attachment-4640\" class=\"wp-caption-text\">Anthracite coal, the highest grade of coal.<\/figcaption><\/figure>\n<p>Humans have used coal for at least 6,000 years, mainly as a fuel source. Coal resources in Wales are often cited as a primary reason for Britain\u2019s rise, and later, for the United States\u2019 rise during the Industrial Revolution. According to the US Energy Information Administration, US coal production has decreased due to competing energy sources\u2019 cheaper prices and due to society recognizing its negative environmental impacts, including increased very fine-grained particulate matter as an air pollutant, greenhouse gases, acid rain, and heavy metal pollution. Seen from this perspective, the coal industry as a source of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossil<\/a> energy is unlikely to revive.<\/p>\n<p>As the world transitions away from fossil fuels including coal, and manufacturing seeks strong, flexible, and lighter materials than steel including carbon fiber for many applications, current research is exploring coal as a source of this carbon.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-110\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-110\" class=\"h5p-iframe\" data-content-id=\"110\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Chapter 16 Review\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_4902\" aria-describedby=\"caption-attachment-4902\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/16.2-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-953\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.2-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-4902\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 16.2 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">16.3 Mineral Resources<\/span><\/h2>\n<figure id=\"attachment_4641\" aria-describedby=\"caption-attachment-4641\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Mother_Lode_Gold_OreHarvard_mine_quartz-gold_vein.jpg\"><img class=\"wp-image-954 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Mother_Lode_Gold_OreHarvard_mine_quartz-gold_vein-300x209.jpg\" alt=\"The yellow gold is inside white quartz.\" width=\"300\" height=\"209\"><\/a><figcaption id=\"caption-attachment-4641\" class=\"wp-caption-text\">Gold-bearing quartz vein from California.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Mineral<\/a>\u00a0resources, while principally\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>, are generally placed\u00a0in two main categories:\u00a0<strong>metallic<\/strong>, which contain metals, and\u00a0<strong>nonmetallic<\/strong>, which contain other useful materials. Most\u00a0mining\u00a0has been traditionally focused on\u00a0extracting metallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. Human society has advanced significantly because we\u2019ve developed the\u00a0knowledge and technologies to yield metal from the Earth. This knowledge has allowed humans to build the machines, buildings, and monetary systems that dominate our world today. Locating and recovering these metals has been a key facet of geologic study since its inception. Every\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>\u00a0across the periodic table has specific applications in human civilization.\u00a0Metallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0mining\u00a0is the source of many of these\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>.<\/p>\n<h3><b>16.3.1. Types of Metallic Mineral Deposits<\/b><\/h3>\n<p>The various ways in which <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0and their associated\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>\u00a0concentrate to form\u00a0ore\u00a0deposits are too complex and numerous to fully review in this text. However, entire careers are built around them.\u00a0In the following section, we describe some of the more common deposit types along with their associated elemental concentrations and world class occurrences.<\/p>\n<h4><span style=\"font-weight: 400\">Magmatic Processes<\/span><\/h4>\n<figure id=\"attachment_4642\" aria-describedby=\"caption-attachment-4642\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/LayeredIntrusionChromitite_Bushveld_South_Africa.jpg\"><img class=\"wp-image-955 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/LayeredIntrusionChromitite_Bushveld_South_Africa-300x211.jpg\" alt=\"The rock has several layers, with the dark layers being the ones with value.\" width=\"300\" height=\"211\"><\/a><figcaption id=\"caption-attachment-4642\" class=\"wp-caption-text\">Layered intrusion of dark chromium-bearing minerals, Bushveld Complex, South Africa<\/figcaption><\/figure>\n<p>When a magmatic body crystallizes and differentiates (see Chapter 4), it can cause certain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> to concentrate. <strong>Layered<\/strong>\u00a0<strong>intrusions<\/strong>, typically <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">ultramafic<\/a> to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">mafic<\/a>, can host deposits that contain copper, nickel, platinum, palladium, rhodium, and chromium. The Stillwater Complex in Montana is an example of economic quantities of layered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">mafic<\/a> intrusion. Associated deposit types can contain chromium or titanium-vanadium. The largest magmatic deposits in the world are the chromite deposits in the Bushveld <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">Igneous<\/a> Complex in South Africa. These rocks have an areal extent larger than the state of Utah. The chromite occurs in layers, which resemble sedimentary layers, except these layers occur within a crystallizing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_232\">magma chamber<\/a>.<\/p>\n<figure id=\"attachment_4909\" aria-describedby=\"caption-attachment-4909\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/Elbai\u0308te_et_mica_Bre\u0301sil_1.jpg\"><img class=\"size-medium wp-image-4909\" src=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/Elbai\u0308te_et_mica_Bre\u0301sil_1-300x199.jpg#fixme\" alt=\"The rock is mostly green and purple\" width=\"300\" height=\"199\"><\/a><figcaption id=\"caption-attachment-4909\" class=\"wp-caption-text\">This pegmatite contains lithium-rich green elbaite (a tourmaline) and purple lepidolite (a mica).<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Water and other\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1684\">volatiles<\/a>\u00a0that are not incorporated into\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0crystals when a\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>\u00a0crystallizes can become\u00a0concentrated\u00a0around the crystallizing\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>\u2019s margins. Ions in these hot fluids are very mobile and can form exceptionally large crystals.\u00a0Once crystallized, these large crystal masses are then called\u00a0<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_996\">pegmatites<\/a><\/strong>. They form from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> fluids that are expelled from the solidifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> when nearly the entire <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> body has crystallized. In addition to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that are predominant in the main <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> mass, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">mica<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_996\">pegmatite<\/a> bodies may also contain very large crystals of unusual <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that contain rare <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> like beryllium, lithium, tantalum, niobium, and tin, as well as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> like gold. Such <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_996\">pegmatites<\/a> are ores of these metals.<\/p>\n<figure id=\"attachment_4643\" aria-describedby=\"caption-attachment-4643\" style=\"width: 298px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/KimberlitePipe.jpg\"><img class=\"wp-image-956 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/KimberlitePipe-298x300.jpg\" alt=\"The pipe is deep and narrow.\" width=\"298\" height=\"300\"><\/a><figcaption id=\"caption-attachment-4643\" class=\"wp-caption-text\">Schematic diagram of a kimberlite pipe.<\/figcaption><\/figure>\n<p>An unusual magmatic process is a\u00a0<strong>kimberlite<\/strong> pipe, which is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_233\">conduit<\/a> that transports <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">ultramafic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> from within the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> to the surface. Diamonds, which are formed at great temperatures and pressures of depth, are transported by a Kimberlite pipe to locations where they can be mined. The process that created these kimberlite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">ultramafic<\/a> rocks is no longer common on Earth. Most known deposits are from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1257\">Archean<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1242\">Eon<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Hydrothermal Processes<\/span><\/h4>\n<figure id=\"attachment_4644\" aria-describedby=\"caption-attachment-4644\" style=\"width: 400px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Deep_sea_vent_chemistry_diagram.jpg\"><img class=\"wp-image-4644\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Deep_sea_vent_chemistry_diagram-1.jpg\" alt=\"The diagram shows water going into the ground and coming out, with many different reactions.\" width=\"400\" height=\"233\"><\/a><figcaption id=\"caption-attachment-4644\" class=\"wp-caption-text\">The complex chemistry around mid-ocean ridges.<\/figcaption><\/figure>\n<p>Fluids rising from crystallizing magmatic bodies or that are heated by the\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_222\">geothermal gradient<\/a>\u00a0cause many geochemical reactions that form various <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0deposits. The most active\u00a0hydrothermal\u00a0process today produces\u00a0<strong>volcanogenic massive sulfide<\/strong><strong>\u00a0<\/strong>(VMS) deposits, which form from black smoker hydrothermal chimney activity near <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> all over the world. They commonly contain copper, zinc, lead, gold, and silver when found at the surface. Evidence from around 7000 BC in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">period<\/a> known as the Chalcolithic shows copper was among the earliest metals smelted by humans as means of obtaining higher temperatures were developed. The largest of these VMS deposits occur in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1270\">Precambrian<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">period<\/a> rocks. The Jerome deposit in central Arizona is a good example.<\/p>\n<p>Another deposit type that draws on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>-heated water is a\u00a0<strong>porphyry<\/strong> deposit. This is not to be confused with the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_994\">porphyritic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> texture, although the name is derived from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_994\">porphyritic<\/a> texture that is nearly always present in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> rocks associated with a porphyry deposit. Several types of porphyry deposits exist, such as porphyry copper, porphyry molybdenum, and porphyry tin. These deposits contain low-grade disseminated ore <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> closely associated with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1007\">intermediate<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1006\">felsic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_991\">intrusive<\/a> rocks that are present over a very large area. Porphyry deposits are typically the largest mines on Earth. One of the largest, richest, and possibly best studied mine in the world is Utah\u2019s Kennecott Bingham Canyon Mine. It\u2019s an open pit mine, which, for over 100 years, has produced several <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> including copper, gold, molybdenum, and silver. Underground <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> replacement deposits produce lead, zinc, gold, silver, and copper. In the mine\u2019s past, the open pit predominately produced copper and gold from chalcopyrite and bornite. Gold only occurs in minor quantities in the copper-bearing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, but because the Kennecott Bingham Canyon Mine produces on such a large scale, it is one of the largest gold <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mines<\/a> in the US. In the future, this mine may produce more copper and molybdenum (molybdenite) from deeper underground mines.<\/p>\n<figure id=\"attachment_4645\" aria-describedby=\"caption-attachment-4645\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Morenci_Mine_2012.jpg\"><img class=\"wp-image-958 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Morenci_Mine_2012-300x200.jpg\" alt=\"The mine contains grey rocks, which are not enriched, and red rocks, which is where the enrichment occurs.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4645\" class=\"wp-caption-text\">The Morenci porphyry is oxidized toward its top (as seen as red rocks in the wall of the mine), creating supergene enrichment.<\/figcaption><\/figure>\n<p>Most porphyry\u00a0copper deposits owe their high metal content, and hence, their economic value to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>\u00a0processes called<strong> supergene enrichment<\/strong> which occurs when the\u00a0deposit is uplifted, eroded, and exposed to\u00a0<strong>oxidation<\/strong>. This process <b>occur<\/b>r<b>ed<\/b> millions of years after the initial <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> intrusion and hydrothermal expulsion ends. When the deposit\u2019s upper pyrite-rich portion is exposed to rain, the pyrite in the oxidizing zone creates an extremely acid condition that dissolves copper out of copper\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>,\u00a0such as chalcopyrite, and converts the chalcopyrite to iron\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a>,\u00a0such as hematite or goethite. The copper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are carried downward in\u00a0water until they arrive at the\u00a0groundwater\u00a0table and an environment where the primary copper\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are converted\u00a0into secondary higher-copper content\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. Chalcopyrite (35% Cu) is converted to bornite (63% Cu), and ultimately, chalcocite (80% Cu).\u00a0Without this enriched zone, which is two to five times higher in copper content than the main deposit, most\u00a0porphyry\u00a0copper deposits would not be economic to mine.<\/p>\n<figure id=\"attachment_4646\" aria-describedby=\"caption-attachment-4646\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.3_6_cm_grossular_calcite_augite_skarn.jpg\"><img class=\"wp-image-959 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.3_6_cm_grossular_calcite_augite_skarn-300x255.jpg\" alt=\"Calcite is blue, augite green, and garnet brown\/orange in this rock.\" width=\"300\" height=\"255\"><\/a><figcaption id=\"caption-attachment-4646\" class=\"wp-caption-text\">Garnet-augite skarn from Italy.<\/figcaption><\/figure>\n<p>If\u00a0limestone\u00a0or other calcareous sedimentary rocks are near the magmatic body, then another type of\u00a0ore\u00a0deposit called a\u00a0<strong>skarn<\/strong>\u00a0deposit forms. These\u00a0metamorphic\u00a0rocks form as\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>-derived, highly saline metalliferous fluids react with\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a>\u00a0rocks to create calcium-magnesium-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a>\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0like\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a>,\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a>, and garnet, as well as high-grade\u00a0iron, copper, zinc\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>,\u00a0and gold. Intrusions that are genetically related to the intrusion that made the Kennecott Bingham Canyon deposit have also produced copper-gold skarns, which were\u00a0mined\u00a0by the early European settlers in Utah. When iron and\/or\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>\u00a0deposits undergo metamorphism, the\u00a0grain\u00a0size\u00a0commonly increases, which makes separating the\u00a0gangue\u00a0from the desired\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>\u00a0or\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a>\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0much easier.<\/p>\n<figure id=\"attachment_4647\" aria-describedby=\"caption-attachment-4647\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/GoldinPyrite.jpg\"><img class=\"wp-image-4647 size-medium\" title=\"&quot;<a\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/GoldinPyrite-1.jpg\" alt=\"The rock is red.\" width=\"300\" height=\"240\"><\/a><figcaption id=\"caption-attachment-4647\" class=\"wp-caption-text\">In this rock, a pyrite cube has dissolved (as seen with the negative \"corner\" impression in the rock), leaving behind small specks of gold.<\/figcaption><\/figure>\n<p><strong>Sediment-hosted disseminated gold<\/strong> deposits consist of low concentrations of microscopic gold as inclusions and disseminated atoms in pyrite crystals. These are formed via low-grade hydrothermal reactions, generally in the realm of diagenesis, that occur in certain rock types, namely muddy <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonates<\/a> and limey mudstones. This hydrothermal alteration is generally far removed from a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> source, but can be found in rocks situated with a high <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_222\">geothermal gradient<\/a>. The Mercur deposit in Utah\u2019s Oquirrh Mountains was this type\u2019s earliest locally mined deposit. There, almost a million ounces of gold was recovered between 1890 and 1917. In the 1960s, a metallurgical process using cyanide was developed for these low-grade ore types. These deposits are also called\u00a0<strong>Carlin-type<\/strong><strong>\u00a0<\/strong>deposits\u00a0because the disseminated deposit near Carlin, Nevada, is where the new technology was first applied and where the first definitive scientific studies were conducted. Gold was introduced into these deposits by\u00a0hydrothermal\u00a0fluids that reacted with silty calcareous rocks, removing\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a>, creating additional permeability, and adding silica and gold-bearing pyrite in the\u00a0pore\u00a0space between grains. The Betze-Post\u00a0mine\u00a0and the Gold Quarry\u00a0mine\u00a0on the Carlin Trend are two of the largest disseminated gold deposits in Nevada. Similar deposits, but not as large, have been found in China, Iran, and Macedonia.<\/p>\n<h4><span style=\"font-weight: 400\">Non-magmatic Geochemical Processes <\/span><\/h4>\n<figure id=\"attachment_4648\" aria-describedby=\"caption-attachment-4648\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.1_UraniumMineUtah.jpg\"><img class=\"wp-image-961 size-medium\" title=\"&quot;<a\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1_UraniumMineUtah-300x225.jpg\" alt=\"A dark shaft runs into the mountain.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4648\" class=\"wp-caption-text\">Underground uranium mine near Moab, Utah.<\/figcaption><\/figure>\n<p>Geochemical processes that occur at or near the surface without <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>\u2019s\u00a0aid also concentrate metals, but to a lesser degree than\u00a0hydrothermal\u00a0processes. One of the main reactions is\u00a0<strong>redox<\/strong>, short for reduction\/oxidation chemistry, which has to do with the amount of available oxygen in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1742\">system<\/a>. Places where oxygen is plentiful, as in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a> today, are considered oxidizing environments, while oxygen-poor places are considered reducing environments. Uranium deposits are an example of where redox concentrated the metal. Uranium is soluble in oxidizing groundwater environments and precipitates as uraninite when encountering reducing conditions. Many of the deposits across the Colorado Plateau, such as in \u00a0Moab, Utah, were formed by this method.<\/p>\n<p>Redox\u00a0reactions are also responsible for creating <strong>banded iron<\/strong><strong>\u00a0<\/strong><strong>formations<\/strong><strong>\u00a0<\/strong>(BIFs),<strong>\u00a0<\/strong>which are interbedded layers of iron\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a>\u2014hematite and magnetite,\u00a0chert, and\u00a0shale\u00a0beds. These deposits formed early in the Earth\u2019s history as the\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a>\u00a0was becoming oxygenated. Cycles of oxygenating iron-rich waters initiated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> of the\u00a0iron\u00a0beds. Because BIFs are generally\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1270\">Precambrian<\/a>\u00a0in age, happening at the event of atmospheric oxygenation, they are only found in some of the older exposed rocks in the United States, such as in Michigan\u2019s upper peninsula and northeast Minnesota.<\/p>\n<figure id=\"attachment_4649\" aria-describedby=\"caption-attachment-4649\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/MV-Type_and_clastic_sediment-hosted_lead-zinc_deposits.svg_.png\"><img class=\"wp-image-962 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MV-Type_and_clastic_sediment-hosted_lead-zinc_deposits.svg_-300x138.png\" alt=\"The are globally distributed.\" width=\"300\" height=\"138\"><\/a><figcaption id=\"caption-attachment-4649\" class=\"wp-caption-text\">Map of Mississippi-Valley type ore deposits.<\/figcaption><\/figure>\n<p>Deep, saline, connate fluids (trapped in pore spaces) within <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_510\">sedimentary basins<\/a>\u00a0may be highly metalliferous. When expelled outward and upward as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> compacted, these fluids formed lead and zinc deposits in limestone by replacing or filling open spaces, such as caves and faults, and in sandstone by filling pore spaces. The most famous are called\u00a0<strong>Mississippi Valley-type<\/strong><strong>\u00a0<\/strong>deposits. Also known as\u00a0carbonate-hosted replacement\u00a0deposits, they are large deposits of galena and sphalerite lead and zinc\u00a0ores that form from hot fluids ranging from 100\u00b0C to 200\u00b0C (212\u00b0F to 392\u00b0F). Although they are named for occurring along the Mississippi\u00a0River\u00a0Valley in the US, they are found worldwide.<\/p>\n<p><strong>Sediment-hosted copper<\/strong><strong>\u00a0<\/strong>deposits occurring in\u00a0sandstones,\u00a0shales, and marls are enormous, and their contained resources are comparable to\u00a0porphyry\u00a0copper deposits. These deposits were most likely formed diagenetically by\u00a0groundwater\u00a0fluids in highly permeable rocks. Well-known examples are the Kupferschiefer in Europe, which has an areal coverage of &gt;500,000 Km<sup>2<\/sup>, (310,685.596mi) and the Zambian Copper Belt in Africa.<\/p>\n<figure id=\"attachment_4650\" aria-describedby=\"caption-attachment-4650\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Bauxite_with_unweathered_rock_core._C_021.jpg\"><img class=\"wp-image-4650 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bauxite_with_unweathered_rock_core._C_021-1.jpg\" alt=\"The outside of the rock is tan and weathered, the inside is grey.\" width=\"300\" height=\"195\"><\/a><figcaption id=\"caption-attachment-4650\" class=\"wp-caption-text\">A sample of bauxite. Note the unweathered igneous rock in the center.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">Soils<\/a>\u00a0and\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0deposits that are exposed at the surface experience deep and intense\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>, which\u00a0can form surficial deposits.\u00a0<strong>Bauxite<\/strong>, an aluminum ore, is preserved in karst topography and laterites, which are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">soils<\/a> formed in wet tropical environments. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">Soils<\/a> containing aluminum concentrate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, and ferromagnesian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> and metamorphic rocks, undergo chemical weathering processes that concentrate the metals. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">Ultramafic<\/a> rocks that undergo <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a> form nickel-rich <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">soils<\/a>, and when the magnetite and hematite in banded iron formations undergo <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>, it forms goethite, a friable <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> that is easily mined for its iron content.<\/p>\n<h3><span style=\"font-weight: 400\">Surficial Physical Processes <\/span><\/h3>\n<figure id=\"attachment_4651\" aria-describedby=\"caption-attachment-4651\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/HeavyMineralsBeachSand.jpg\"><img class=\"wp-image-4651 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/HeavyMineralsBeachSand-1.jpg\" alt=\"The tan rock has dark streaks of minerals.\" width=\"300\" height=\"205\"><\/a><figcaption id=\"caption-attachment-4651\" class=\"wp-caption-text\">Lithified heavy mineral sand (dark layers) from a beach deposit in India.<\/figcaption><\/figure>\n<p>At the Earth\u2019s surface, mass wasting\u00a0and moving water can cause hydraulic\u00a0sorting, which forces high-density\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> to concentrate. When these\u00a0minerals\u00a0are\u00a0concentrated\u00a0in\u00a0streams,\u00a0rivers,\u00a0and beaches, they are called\u00a0<strong>placer<\/strong>\u00a0deposits, and occur in modern sands and ancient lithified rocks.\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">Native<\/a>\u00a0gold,\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a>\u00a0platinum,\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1227\">zircon<\/a>, ilmenite, rutile, magnetite, diamonds, and other gemstones can be found in\u00a0placers. Humans have mimicked this natural process to recover gold manually by gold panning and by mechanized means such as dredging.<\/p>\n<h3><b>16.3.2. Environmental Impacts of Metallic Mineral Mining<\/b><\/h3>\n<figure id=\"attachment_4652\" aria-describedby=\"caption-attachment-4652\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Rio_tinto_river_CarolStoker_NASA_Ames_Research_Center.jpg\"><img class=\"wp-image-965 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Rio_tinto_river_CarolStoker_NASA_Ames_Research_Center-300x225.jpg\" alt=\"The water in the river is bright orange.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4652\" class=\"wp-caption-text\">Acid mine drainage in the Rio Tinto, Spain.<\/figcaption><\/figure>\n<p>Metallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0mining\u2019s\u00a0primary impact comes from the\u00a0mining\u00a0itself, including disturbing the land surface, covering landscapes with tailings impoundments, and increasing\u00a0mass wasting\u00a0by accelerating\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1755\">erosion<\/a>. In addition, many metal deposits contain pyrite, an uneconomic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>, that when\u00a0placed on waste dumps, generates\u00a0<strong>acid rock drainage<\/strong>\u00a0(ARD)<strong>\u00a0<\/strong>during <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>. In oxygenated water, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfides<\/a> such as pyrite react and undergo complex reactions to release metal ions and hydrogen ions, which lowers pH to highly acidic levels. Mining and processing of mined materials typically increase the surface area to volume ratio in the material, causing chemical reactions to occur even faster than would occur naturally. If not managed properly, these reactions lead to acidic streams and groundwater plumes that carry dissolved toxic metals. In mines where limestone is a waste rock or where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> or dolomite are present, their acid neutralizing potential helps reduce acid rock drainage. Although this is a natural process too, it is very important to isolate mine dumps and tailings from oxygenated water, both to prevent the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfides<\/a> from dissolving and subsequently percolating the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_974\">sulfate<\/a>-rich water into waterways. Industry has taken great strides to prevent contamination in recent decades, but earlier mining projects are still causing problems with local ecosystems.<\/p>\n<h3><strong>16.3.3. Nonmetallic Mineral\u00a0Deposits<\/strong><\/h3>\n<figure id=\"attachment_4653\" aria-describedby=\"caption-attachment-4653\" style=\"width: 225px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/CarraraMarblequarry.jpg\"><img class=\"wp-image-966 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/CarraraMarblequarry-225x300.jpg\" alt=\"The image shows a hillside with blocks of marble removed.\" width=\"225\" height=\"300\"><\/a><figcaption id=\"caption-attachment-4653\" class=\"wp-caption-text\">Carrara marble quarry in Italy, source to famous sculptures like Michelangelo's David.<\/figcaption><\/figure>\n<p>While receiving much less attention, nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> resources, also known as industrial <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, are just as vital to ancient and modern society as metallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. The most basic is building stone. Limestone, travertine, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1014\">granite<\/a>, slate, and marble are common building stones and have been quarried for centuries. Even today, building stones from slate roof tiles to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1014\">granite<\/a> countertops are very popular. Especially pure limestone is ground up, processed, and reformed as plaster, cement, and concrete. Some nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> resources are not <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> specific; nearly any rock or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> can be used. This is generally called aggregate, which is used in concrete, roads, and foundations. Gravel is one of the more common aggregates.<\/p>\n<h4><span style=\"font-weight: 400\">Evaporites<\/span><\/h4>\n<figure id=\"attachment_4654\" aria-describedby=\"caption-attachment-4654\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Bonneville_Salt_Flats_Utah.jpg\"><img class=\"wp-image-4654 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bonneville_Salt_Flats_Utah-1.jpg\" alt=\"The ground is white and flat for a long distance.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4654\" class=\"wp-caption-text\">Salt-covered plain known as the Bonneville Salt Flats, Utah.<\/figcaption><\/figure>\n<p><strong>Evaporite<\/strong><strong>\u00a0<\/strong>deposits\u00a0form in restricted basins where water evaporates faster than it recharges, such as the Great Salt Lake in Utah, or the Dead Sea, which borders Israel and Jordan. As the waters evaporate, soluble\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0are\u00a0concentrated\u00a0and become supersaturated, at which point they\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitate<\/a>\u00a0from the now highly-saline waters. If these conditions persist for long stretches, thick rock salt, rock\u00a0gypsum,\u00a0and other\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0deposits accumulate (see Chapter 5).<\/p>\n<figure id=\"attachment_4655\" aria-describedby=\"caption-attachment-4655\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Hanksite.jpg\"><img class=\"wp-image-968 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hanksite-300x200.jpg\" alt=\"The mineral is hexagonal and clear.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4655\" class=\"wp-caption-text\">Hanksite, Na22K(SO4)9(CO3)2Cl, one of the few minerals that is considered a carbonate and a sulfate<\/figcaption><\/figure>\n<p>Evaporite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, such as halite, are used in our food as common table salt. Salt was a vitally important food preservative and economic resource before refrigeration was developed. While still used in food, halite is now mainly mined as a chemical agent, water softener, or road de-icer. Gypsum is a common nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> used as a building material; it is the main component in dry wall. It is also used as a fertilizer. Other evaporites include sylvite\u2014potassium chloride, and bischofite\u2014magnesium chloride, both of which are used in agriculture, medicine, food processing, and other applications. Potash, a group of highly soluble potassium-bearing evaporite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, is used as a fertilizer. In hyper-arid locations, even more rare and complex evaporites, like borax, trona, ulexite, and hanksite are mined. They can be found in places such as Searles Dry Lake and Death Valley, California, and in the Green River Formation\u2019s ancient evaporite deposits in Utah and Wyoming.<\/p>\n<h4><span style=\"font-weight: 400\">Phosphorus<\/span><\/h4>\n<figure id=\"attachment_4656\" aria-describedby=\"caption-attachment-4656\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Apatite-CaF-280343.jpg\"><img class=\"wp-image-4656 size-medium\" title=\"&quot;Rob\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Apatite-CaF-280343-1.jpg\" alt=\"The crystal is hexagonal and light green.\" width=\"300\" height=\"267\"><\/a><figcaption id=\"caption-attachment-4656\" class=\"wp-caption-text\">Apatite from Mexico.<\/figcaption><\/figure>\n<p>Phosphorus is an essential <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> that occurs in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> apatite, which is found in trace amounts in common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> rocks. Phosphorite rock, which is formed in sedimentary environments in the ocean, contains abundant apatite and is mined to make fertilizer. Without phosphorus, life as we know it is not possible. Phosphorous is an important component of bone and DNA. Bone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1001\">ash<\/a> and guano are natural sources of phosphorus.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<figure id=\"attachment_4903\" aria-describedby=\"caption-attachment-4903\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/16.3-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-970\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.3-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-4903\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 16.3 via this QR Code.<\/figcaption><\/figure>\n<h1>Summary<\/h1>\n<p>Energy and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> resources are vital to modern society, and it is the role of the geologist to locate these resources for human benefit. As environmental concerns have become more prominent, the value of the geologist has not decreased, as they are still vital in locating the deposits and identifying the least <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_991\">intrusive<\/a> methods of extraction.<\/p>\n<p>Energy resources are general grouped as being <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>. Geologists can aid in locating the best places to exploit <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> resources (e.g. locating a dam), but are commonly tasked with finding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> fossil fuels. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Mineral<\/a> resources are also grouped in two categories: metallic and nonmetallic. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> have a wide variety of processes that concentrate them to economic levels, and are usually mined via surface or underground methods.<\/p>\n<h3>Take this quiz to check your comprehension of this Chapter.<\/h3>\n<figure id=\"attachment_4904\" aria-describedby=\"caption-attachment-4904\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/Ch.16-Review-QR-Code.png\"><img class=\"size-thumbnail wp-image-971\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.16-Review-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-4904\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the review quiz for Chapter 16 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">References<\/span><\/h2>\n<ol>\n<li style=\"text-align: left\">Ague, Jay James, and George H. Brimhall. 1989. \u201cGeochemical Modeling of Steady State Fluid Flow and Chemical Reaction during Supergene Enrichment of Porphyry Copper Deposits.\u201d <em>Economic Geology and the Bulletin of the Society of Economic Geologists<\/em> 84 (3). economicgeology.org: 506\u201328.<\/li>\n<li style=\"text-align: left\">Arndt, N. T. 1994. \u201cChapter 1 Archean Komatiites.\u201d In <em>Developments in Precambrian Geology<\/em>, edited by K.C. Condie, 11:11\u201344. Elsevier.<\/li>\n<li style=\"text-align: left\">B\u00e1rdossy, Gy\u00f6rgy, and Gerardus Jacobus Johannes Aleva. 1990. <em>Lateritic Bauxites<\/em>. Vol. 27. Elsevier Science Ltd.<\/li>\n<li style=\"text-align: left\">Barrie, C. T. 1999. \u201cVolcanic-Associated Massive Sulfide Deposits: Processes and Examples in Modern and Ancient Settings.\u201d Reviews in Economic Geology, v. 8. https:\/\/www.researchgate.net\/profile\/Michael_Perfit\/publication\/241276560_Geologic_petrologic_and_geochemical_relationships_between_magmatism_and_massive_sulfide_mineralization_along_the_eastern_Galapagos_Spreading_Center\/links\/02e7e51c8707bbfe9c000000.pdf.<\/li>\n<li style=\"text-align: left\">Barrie, L. A., and R. M. Hoff. 1984. \u201cThe Oxidation Rate and Residence Time of Sulphur Dioxide in the Arctic Atmosphere.\u201d <em>Atmospheric Environment<\/em> 18 (12). Elsevier: 2711\u201322.<\/li>\n<li style=\"text-align: left\">Bauquis, Pierre-Ren\u00e9. 1998. \u201cWhat Future for Extra Heavy Oil and Bitumen: The Orinoco Case.\u201d In <em>Paper Presented by TOTAL at the World Energy Congress<\/em>, 13:18.<\/li>\n<li style=\"text-align: left\">Belloc, H. 1913. <em>The Servile State<\/em>. T.N. Foulis.<\/li>\n<li style=\"text-align: left\">Blander, M., S. Sinha, A. Pelton, and G. Eriksson. 2011. \u201cCalculations of the Influence of Additives on Coal Combustion Deposits.\u201d <em>Argonne National Laboratory, Lemont, Illinois<\/em>. enersol.pk, 315.<\/li>\n<li style=\"text-align: left\">Boudreau, Alan E. 2016. \u201cThe Stillwater Complex, Montana--Overview and the Significance of Volatiles.\u201d <em>Mineralogical Magazine<\/em> 80 (4). Mineralogical Society: 585\u2013637.<\/li>\n<li style=\"text-align: left\">Bromfield, C. S., A. J. Erickson, M. A. Haddadin, and H. H. Mehnert. 1977. \u201cPotassium-Argon Ages of Intrusion, Extrusion, and Associated Ore Deposits, Park City Mining District, Utah.\u201d <em>Economic Geology and the Bulletin of the Society of Economic Geologists<\/em> 72 (5). economicgeology.org: 837\u201348.<\/li>\n<li style=\"text-align: left\">Brown, Valerie J. 2007. \u201cIndustry Issues: Putting the Heat on Gas.\u201d Environmental Health Perspectives 115 (2). ncbi.nlm.nih.gov: A76.<\/li>\n<li style=\"text-align: left\">Cabri, Louis J., Donald C. Harris, and Thorolf W. Weiser. 1996. \u201cMineralogy and Distribution of Platinum-Group Mineral (PGM) Placer Deposits of the World.\u201d <em>Exploration and Mining Geology<\/em> 2 (5). infona.pl: 73\u2013167.<\/li>\n<li style=\"text-align: left\">Crutzen, Paul J., and Jos Lelieveld. 2001. \u201cHuman Impacts on Atmospheric Chemistry.\u201d <em>Annual Review of Earth and Planetary Sciences<\/em> 29 (1). Annual Reviews 4139 El Camino Way, PO Box 10139, Palo Alto, CA 94303-0139, USA: 17\u201345.<\/li>\n<li style=\"text-align: left\">Delaney, M. L. 1998. \u201cPhosphorus Accumulation in Marine Sediments and the Oceanic Phosphorus Cycle.\u201d <em>Global Biogeochemical Cycles<\/em> 12 (4). Wiley Online Library: 563\u201372.<\/li>\n<li style=\"text-align: left\">Demaison, G. J., and G. T. Moore. 1980. \u201cAnoxic Environments and Oil Source Bed Genesis.\u201d Organic Geochemistry 2 (1). Elsevier: 9\u201331.<\/li>\n<li style=\"text-align: left\">Dott, Robert H., and Merrill J. Reynolds. 1969. \u201cSourcebook for Petroleum Geology.\u201d American Association of Petroleum Geologists Tulsa, Okla. http:\/\/archives.datapages.com\/data\/specpubs\/methodo1\/data\/a072\/a072\/0001\/0000\/vi.htm.<\/li>\n<li style=\"text-align: left\">Duffield, Wendell A. 2005. \u201cVolcanoes, Geothermal Energy, and the Environment.\u201d <em>Volcanoes and the Environment<\/em>. Cambridge University Press, 304.<\/li>\n<li style=\"text-align: left\">Einaudi, Marco T., and Donald M. Burt. 1982. \u201cIntroduction; Terminology, Classification, and Composition of Skarn Deposits.\u201d <em>Economic Geology and the Bulletin of the Society of Economic Geologists<\/em> 77 (4). economicgeology.org: 745\u201354.<\/li>\n<li style=\"text-align: left\">Gandossi, Luca. 2013. \u201cAn Overview of Hydraulic Fracturing and Other Formation Stimulation Technologies for Shale Gas Production.\u201d <em>Eur. Commisison Jt. Res. Cent. Tech. Reports<\/em>. skalunudujos.lt. http:\/\/skalunudujos.lt\/wp-content\/uploads\/an-overview-of-hydraulic-fracturing-and-other-stimulation-technologies.pdf.<\/li>\n<li style=\"text-align: left\">Gordon, Mackenzie, Jr, Joshua I. Tracey Jr, and Miller W. Ellis. 1958. \u201cGeology of the Arkansas Bauxite Region.\u201d pubs.er.usgs.gov. https:\/\/pubs.er.usgs.gov\/publication\/pp299.<\/li>\n<li style=\"text-align: left\">Gordon, W. 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M. Widmier, J. N. Bubb, and W. G. Hatelid. 1977. \u201cSeismic Stratigraphy and Global Sea Level Changes.\u201d <em>Seismic Stratigraphy-Applications to Hydrocarbon Exploration, Edited by Payton, CE, Tulsa, American Association of Petroleum Geologists Memoir<\/em> 26: 49\u2013212.<\/li>\n<li style=\"text-align: left\">Vogel, J. C. 1970. \u201cGroningen Radiocarbon Dates IX.\u201d <em>Radiocarbon<\/em> 12 (2). journals.uair.arizona.edu: 444\u201371.<\/li>\n<li style=\"text-align: left\">Willemse, J. 1969. \u201cThe Geology of the Bushveld Igneous Complex, the Largest Repository of Magmatic Ore Deposits in the World.\u201d <em>Economic Geology Monograph<\/em> 4: 1\u201322.<\/li>\n<li style=\"text-align: left\">Wrigley, E. A. 1990. <em>Continuity, Chance and Change: The Character of the Industrial Revolution in England. Ellen McArthur Lectures<\/em> ; 1987. Cambridge University Press.<\/li>\n<li style=\"text-align: left\">Youngquist, Walter. 1998. \u201cShale Oil--The Elusive Energy.\u201d <em>Hubbert Center Newsletter<\/em> 4.<\/li>\n<\/ol>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_974\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_974\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_969\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_969\"><div tabindex=\"-1\"><p>Rob Lavinsky, <a rel=\"nofollow\" class=\"external text\" href=\"http:\/\/www.irocks.com\/\">iRocks.com<\/a> \u2013 CC-BY-SA-3.0 [<a href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/3.0\">CC BY-SA 3.0<\/a>], <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File%3AApatite-(CaF)-280343.jpg\">via Wikimedia Commons<\/a><\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1767\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1767\"><div tabindex=\"-1\"><p>Sedimentary rocks made of mineral grains weathered as mechanical detritus of previous rocks, e.g. sand, gravel, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1909\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1909\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_970\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_970\"><div tabindex=\"-1\"><p>QR Code generated with QRCode Monkey. All generated QR Codes are 100% free and can be used for whatever you want. This includes all commercial purposes. <\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1905\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1905\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1934\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1934\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_999\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_999\"><div tabindex=\"-1\"><p>The outer physical&nbsp;layer of the core, which is liquid. Movement within the outer core is believed to be responsible for Earth's magnetic field and flips of the magnetic field.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1753\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1753\"><div tabindex=\"-1\"><p>Metallic mineral deposit which forms near mid-ocean ridges.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_251\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_251\"><div tabindex=\"-1\"><p>By Michael C. Rygel (Own work) [<a href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/3.0\">CC BY-SA 3.0<\/a>], <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File%3AAndesite2.tif\">via Wikimedia Commons<\/a><\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1890\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1890\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1785\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1785\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1783\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1783\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1992\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1992\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1779\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1779\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1653\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1653\"><div tabindex=\"-1\"><p>Erosional rock face caused by sand abrasion.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2449\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2449\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1789\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1789\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2439\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2439\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1780\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1780\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1782\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1782\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1896\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1896\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1922\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1922\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1752\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1752\"><div tabindex=\"-1\"><p>An ultramafic rock from deep volcanic vents that can contain diamonds.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1750\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1750\"><div tabindex=\"-1\"><p>Minerals that have a luster that is not similar to metal, and typically do not contain valuable metals like copper, lead, zinc, tin, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1893\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1893\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1784\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1784\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2197\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2197\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1756\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1756\"><div tabindex=\"-1\"><p>Carbonate rock that reacts with hot magmatic fluids, creating concentrated ore deposits, which include copper, iron, zinc, and gold.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1924\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1924\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_747\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_747\"><div tabindex=\"-1\"><p>https:\/\/waterdata.usgs.gov\/nwis\/dv\/?ts_id=143976&amp;format=img_default&amp;site_no=404356111503901&amp;set_arithscale_y=on&amp;begin_date=19750718&amp;end_date=19890930<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1925\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1925\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2240\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2240\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2252\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2252\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2212\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2212\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1751\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1751\"><div tabindex=\"-1\"><p>Metallic mineral deposit consisting of mafic plutonic rocks, typically containing platinum-group elements, chromium, copper, nickel, etc.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2440\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2440\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1961\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1961\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1963\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1963\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1761\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1761\"><div tabindex=\"-1\"><p>A highly weathered soil deposit that consists of aluminum ores.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1929\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1929\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1927\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1927\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1274\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1274\"><div tabindex=\"-1\"><p>A sedimentary structure that forms in the lower flow regime, where ridges of sediment form perpendicular to flow direction, but within the ridges, sediment layers and dips toward flow direction. Found in ripples and dunes. Can be tabular, sinuous, or trough shaped.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_975\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_975\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1228\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1228\"><div tabindex=\"-1\"><p>Lowest layer of the soil (C), which is mechanically weathered (not chemically weathered) bedrock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1664\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1664\"><div tabindex=\"-1\"><p>Dunes that form semicircular shapes due to anchoring vegetation.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1658\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1658\"><div tabindex=\"-1\"><p>Dangerous flooding that occurs in arid regions.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1666\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1666\"><div tabindex=\"-1\"><p>Term for the extensional tectonic province that extends from California's Sierra Nevada Mountains in the west, to Utah's Wasatch Mountains to the east, to southern Oregon and Idaho to the north, to northern Mexico to the south. Known as a wide rift, as each graben 'basin,' bounded by horst 'ranges.' Each set of horsts with a graben has some individual extension, adding up to the overall rifting.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1013\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1013\"><div tabindex=\"-1\"><p>A chain of volcanic activity, typically in a curved pattern, rising from a subduction zone. The arc is on the overriding plate, typically a few hundred kilometers from the trench, but parallel to the trench.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1786\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1786\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1008\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1008\"><div tabindex=\"-1\"><p>Mix of sediments that form as a subducting plate descends and the overriding plate scrapes material and material is added.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1654\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1654\"><div tabindex=\"-1\"><p>Rock with abraded surfaces formed in deserts.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1669\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1669\"><div tabindex=\"-1\"><p>Glaciers that form in cool or mountainous areas.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1680\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1680\"><div tabindex=\"-1\"><p>Smooth surface carved in harder rocks by glacial action.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1227\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1227\"><div tabindex=\"-1\"><p>Lower layer of the soil (B) which is a mixture of weathered bedrock, leeched materials, and organic material. Has two sublayers: the upper part, or regolith (with more organic materials), and the lower part, saprolite, which is only slightly weathered bedrock.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2016\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2016\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1790\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1790\"><div tabindex=\"-1\"><figure id=\"attachment_1683\" aria-describedby=\"caption-attachment-1683\" style=\"width: 3648px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/DT1-2-scaled.jpg\" target=\"_blank\" rel=\"noopener\"><img class=\"wp-image-1683 size-full\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/DT1-2-scaled-1.jpg\" alt=\"It is a steep rock jutting out of the countryside.\" width=\"3648\" height=\"2736\"><\/a><figcaption id=\"caption-attachment-1683\" class=\"wp-caption-text\">Devils Tower, Wyoming.<\/figcaption><\/figure>\n<h1><strong>1 Understanding Science<\/strong><\/h1>\n<p><b>STUDENT LEARNING OUTCOMES<\/b><\/p>\n<p><b>At the end of this chapter, students should be able to:<\/b><\/p>\n<ul>\n<li>Contrast <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a>\u00a0versus <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1723\">subjective<\/a>\u00a0observations, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1724\">quantitative<\/a>\u00a0versus <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1725\">qualitative<\/a>\u00a0observations<\/li>\n<li>Identify a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1727\">pseudoscience<\/a>\u00a0based on its lack of falsifiability<\/li>\n<li>Contrast the methods used by Aristotle and Galileo to describe the natural environment<\/li>\n<li>Explain the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a>\u00a0and apply it to a problem or question<\/li>\n<li>Describe the foundations of modern geology, such as the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">principle of uniformitarianism<\/a><\/li>\n<li>Contrast <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">uniformitarianism<\/a>\u00a0with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1737\">catastrophism<\/a><\/li>\n<li>Explain why studying geology is important<\/li>\n<li>Identify how Earth materials are transformed by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1749\">rock cycle<\/a>\u00a0processes<\/li>\n<li>Describe the steps involved in a reputable scientific study<\/li>\n<li>Explain rhetorical arguments used by science deniers<\/li>\n<\/ul>\n<h2><span style=\"font-weight: 400\">1.1 <\/span><b>What is Science?<\/b><\/h2>\n<figure id=\"attachment_1627\" aria-describedby=\"caption-attachment-1627\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/YS1-1.jpg\" target=\"_blank\" rel=\"noopener\"><img class=\"wp-image-21 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/YS1-1-300x225.jpg\" alt=\"The waterfall is in a valley\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-1627\" class=\"wp-caption-text\">This is Grand Canyon of the Yellowstone in Yellowstone National Park. An objective statement about this would be: \"The picture is of a waterfall.\" A subjective statement would be: \"The picture is beautiful.\" or \"The waterfall is there because of erosion.\"<\/figcaption><\/figure>\n<p>Scientists seek to understand the fundamental principles that explain natural patterns and processes. Science is more than just a body of knowledge, science provides a means to evaluate and create new knowledge without bias. Scientists use <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> evidence over <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1723\">subjective<\/a> evidence, to reach sound and logical conclusions.<\/p>\n<p>An <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1729\">observation<\/a> is without personal bias and the same by all individuals. Humans are biased by nature, so they cannot be completely <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a>; the goal is to be as unbiased as possible. A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1723\">subjective<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1729\">observation<\/a> is based on a person\u2019s feelings and beliefs and is unique to that individual.<\/p>\n<p>Another way scientists avoid bias is by using <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1724\">quantitative<\/a> over <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1725\">qualitative<\/a> measurements whenever possible. A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1724\">quantitative<\/a> measurement is expressed with a specific numerical value. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1725\">Qualitative<\/a> observations are general or relative descriptions. For example, describing a rock as red or heavy is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1725\">qualitative<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1729\">observation<\/a>. Determining a rock\u2019s color by measuring wavelengths of reflected light or its density by measuring the proportions of minerals it contains is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1724\">quantitative<\/a>. Numerical values are more precise than general descriptions, and they can be analyzed using statistical calculations. This is why <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1724\">quantitative<\/a> measurements are much more useful to scientists than <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1725\">qualitative<\/a> observations.<\/p>\n<figure id=\"attachment_2460\" aria-describedby=\"caption-attachment-2460\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/MSH_Alex-2-scaled.jpg\" target=\"_blank\" rel=\"noopener\"><img class=\"wp-image-2460 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MSH_Alex-2-scaled-1.jpg\" alt=\"A person is looking into the canyon.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-2460\" class=\"wp-caption-text\">Canyons like this, carved in the deposit left by the May 18th, 1980 eruption of Mt. St. Helens is sometimes used by purveyors of pseudoscience as evidence for the Earth being very young. In reality, the unconsolidated and unlithified volcanic deposit is carved much more easily than other canyons like the Grand Canyon.<\/figcaption><\/figure>\n<p>Establishing truth in science is difficult because all scientific claims are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1726\">falsifiable<\/a>, which means any initial <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> may be tested and proven false. Only after exhaustively eliminating false results, competing ideas, and possible variations does a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> become regarded as a reliable scientific <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a>. This meticulous scrutiny reveals weaknesses or flaws in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> and is the strength that supports all scientific ideas and procedures. In fact, proving current ideas are wrong has been the driving force\u00a0behind many scientific careers.<\/p>\n<p>Falsifiability separates science from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1727\">pseudoscience<\/a>. Scientists are wary of explanations of natural phenomena that discourage or avoid falsifiability. An explanation that cannot be tested or does not meet scientific standards is not considered science, but <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1727\">pseudoscience<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1727\">Pseudoscience<\/a> is a collection of ideas that may appear scientific but does not use the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a>. Astrology is an example of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1727\">pseudoscience<\/a>. It is a belief system that attributes the movement of celestial bodies to influencing human behavior. Astrologers rely on celestial observations, but their conclusions are not based on experimental evidence and their statements are not <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1726\">falsifiable<\/a>. This is not to be confused with astronomy which is the scientific study of celestial bodies and the cosmos<span style=\"font-weight: 400\">.<\/span><\/p>\n<figure id=\"attachment_2461\" aria-describedby=\"caption-attachment-2461\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/DSC00761-2-scaled.jpg\"><img class=\"wp-image-2461 size-medium\" title=\"Source: By Matt Affolter\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/DSC00761-2-scaled-1.jpg\" alt=\"Many people are standing around and talking.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-2461\" class=\"wp-caption-text\">Geologists share information by publishing, attending conferences, and even going on field trips, such as this trip to western Utah by the Utah Geological Association in 2009.<\/figcaption><\/figure>\n<p>Science is also a social process. Scientists share their ideas with peers at conferences, seeking guidance and feedback. Research papers and data submitted for publication are rigorously reviewed by qualified peers, scientists who are experts in the same field. The scientific review process aims to weed out misinformation, invalid research results, and wild speculation. Thus, it is slow, cautious, and conservative. Scientists tend to wait until a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> is supported by overwhelming amount of evidence from many independent researchers before accepting it as scientific <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a>.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-1\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-1\" class=\"h5p-iframe\" data-content-id=\"1\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1.1 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3715\" aria-describedby=\"caption-attachment-3715\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/1.1-Did-I-Get-It.png\"><img class=\"wp-image-24 size-thumbnail\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/1.1-Did-I-Get-It-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3715\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 1.1 via this QR Code.<\/figcaption><\/figure>\n<h2><strong>1.2 The Scientific Method<\/strong><\/h2>\n<figure id=\"attachment_2462\" aria-describedby=\"caption-attachment-2462\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/The_Scientific_Method_as_an_Ongoing_Process.svg_-2.png\"><img class=\"wp-image-25 size-medium\" title=\"Source: By ArchonMagnus (Own work) [<a href=&quot;http:\/\/creativecommons.org\/licenses\/by-sa\/4.0&quot;><figcaption id=\"caption-attachment-2462\" class=\"wp-caption-text\">CC BY-SA 4.0<\/a>], <a href=&quot;https:\/\/commons.wikimedia.org\/wiki\/File%3AThe_Scientific_Method_as_an_Ongoing_Process.svg&quot;>via Wikimedia Commons<\/a>\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/The_Scientific_Method_as_an_Ongoing_Process.svg_-2-300x247.png\" alt=\"The diagram is cyclical.\" width=\"300\" height=\"247\"><\/a> Diagram of the cyclical nature of the scientific method.<\/figcaption><\/figure>\n<p><span style=\"text-align: initial;font-size: 1em\">Modern science is based on the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a>, a procedure that follows these steps:<\/span><\/p>\n<ul>\n<li>Formulate a question or observe a problem<\/li>\n<li>Apply <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> experimentation and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1729\">observation<\/a><\/li>\n<li>Analyze collected data and Interpret results<\/li>\n<li>Devise an evidence-based <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a><\/li>\n<li>Submit findings to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1732\">peer review<\/a> and\/or publication<\/li>\n<\/ul>\n<p>This has a long history in human thought but was first fully formed by Ibn al-Haytham over 1,000 years ago. At the forefront of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a> are conclusions based on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> evidence, not opinion or hearsay<span style=\"font-weight: 400\">. <\/span><\/p>\n<h4><strong>Step One: Observation, Problem, or Research Question<\/strong><\/h4>\n<p>The procedure begins with identifying a problem or research question, such as a geological phenomenon that is not well explained in the scientific community\u2019s collective knowledge. This step usually involves reviewing the scientific literature to understand previous studies that may be related to the question.<\/p>\n<h4><strong>Step Two: Hypothesis<\/strong><\/h4>\n<figure id=\"attachment_2463\" aria-describedby=\"caption-attachment-2463\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Eadweard_Muybridge-Sallie_Gardner_1878-1.jpg\"><img class=\"wp-image-26 size-medium\" title=\"Source: By Eadweard Muybridge, public domain.\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Eadweard_Muybridge-Sallie_Gardner_1878-1-300x187.jpg\" alt=\"There are 12 images of the horse, at least one has the legs off the ground.\" width=\"300\" height=\"187\"><\/a><figcaption id=\"caption-attachment-2463\" class=\"wp-caption-text\">A famous hypothesis: Leland Stanford wanted to know if a horse lifted all 4 legs off the ground during a gallop, since the legs are too fast for the human eye to perceive it. These series of photographs by Eadweard Muybridge proved the horse, in fact, does have all four legs off the ground during the gallop.<\/figcaption><\/figure>\n<p>Once the problem or question is well defined, the scientist proposes a possible answer, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a>, before conducting an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1731\">experiment<\/a> or field work. This <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> must be specific, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1726\">falsifiable<\/a>, and should be based on other scientific work. Geologists often develop multiple working <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypotheses<\/a> because they usually cannot impose strict experimental controls or have limited opportunities to visit a field location.<\/p>\n<h4><strong>Step Three: Experiment and Hypothesis Revision<\/strong><\/h4>\n<figure id=\"attachment_2464\" aria-describedby=\"caption-attachment-2464\" style=\"width: 199px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/University_of_Queensland_Pitch_drop_experiment-white_bg-1.jpg\"><img class=\"size-medium wp-image-27\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/University_of_Queensland_Pitch_drop_experiment-white_bg-1-199x300.jpg\" alt=\"The setup is like an hourglass, and the black pitch sits in it\" width=\"199\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2464\" class=\"wp-caption-text\">An experiment at the University of Queensland has been going since 1927. A petroleum product called pitch, which is highly viscous, drips out of a funnel about once per decade.<\/figcaption><\/figure>\n<p>The next step is developing an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1731\">experiment<\/a> that either supports or refutes the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a>. Many people mistakenly think experiments are only done in a lab; however, an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1731\">experiment<\/a> can consist of observing natural processes in the field. Regardless of what form an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1731\">experiment<\/a> takes, it always includes the systematic gathering of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> data. This data is interpreted to determine whether it contradicts or supports the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a>, which may be revised and tested again. When a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> holds up under experimentation, it is ready to be shared with other experts in the field.<\/p>\n<h4><strong>Step Four: Peer Review, Publication, and Replication<\/strong><\/h4>\n<p>Scientists share the results of their research by publishing articles in scientific journals, such as <em>Science<\/em> and <em>Nature<\/em>. Reputable journals and publishing houses will not publish an experimental study until they have determined its methods are scientifically rigorous and the conclusions are supported by evidence. Before an article is published, it undergoes a rigorous <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1732\">peer review<\/a> by scientific experts who scrutinize the methods, results, and discussion. Once an article is published, other scientists may attempt to replicate the results. This replication is necessary to confirm the reliability of the study\u2019s reported results. A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> that seemed compelling in one study might be proven false in studies conducted by other scientists. New technology can be applied to published studies, which can aid in confirming or rejecting once-accepted ideas and\/or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypotheses<\/a>.<\/p>\n<h4><strong>Step Five: Theory Development<\/strong><\/h4>\n<figure id=\"attachment_2500\" aria-describedby=\"caption-attachment-2500\" style=\"width: 195px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Alfred_Wegener_ca.1924-30-2.jpg\"><img class=\"size-full wp-image-28\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Alfred_Wegener_ca.1924-30-2.jpg\" alt=\"He is a male in a suit.\" width=\"195\" height=\"240\"><\/a><figcaption id=\"caption-attachment-2500\" class=\"wp-caption-text\">Wegener later in his life, ca. 1924-1930.<\/figcaption><\/figure>\n<p>In casual conversation, the word <em><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a><\/em> implies guesswork or speculation. In the language of science, an explanation or conclusion made in a <em><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a><\/em> carries much more weight because it is supported by experimental verification and widely accepted by the scientific community. After a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> has been repeatedly tested for falsifiability through documented and independent studies, it eventually becomes accepted as a scientific <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a>.<\/p>\n<p>While a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> provides a tentative explanation <em>before <\/em>an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1731\">experiment<\/a>, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> is the best explanation <em>after <\/em>being confirmed by multiple independent experiments. Confirmation of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> may take years, or even longer. For example, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> drift <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> first proposed by Alfred Wegener in 1912 was initially dismissed. After decades of additional evidence collection by other scientists using more advanced technology, Wegener\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> was accepted and revised as the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a>.<\/p>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of evolution by natural selection is another example. Originating from the work of Charles Darwin in the mid-19th century, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of evolution has withstood generations of scientific testing for falsifiability. While it has been updated and revised to accommodate knowledge gained by using modern technologies, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of evolution continues to be supported by the latest evidence.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-2\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-2\" class=\"h5p-iframe\" data-content-id=\"2\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1.2 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3714\" aria-describedby=\"caption-attachment-3714\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/1.2-Did-I-Get-It.png\"><img class=\"wp-image-29 size-thumbnail\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/1.2-Did-I-Get-It-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3714\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 1.2 via this QR Code.<\/figcaption><\/figure>\n<h2>1.3 Early Scientific Thought<\/h2>\n<figure id=\"attachment_2466\" aria-describedby=\"caption-attachment-2466\" style=\"width: 229px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Sanzio_01_Plato_Aristotle-1.jpg\"><img class=\"wp-image-30 size-medium\" title=\"Source: &quot;School of Athens&quot; by Raphael Date1509 Medium fresco\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Sanzio_01_Plato_Aristotle-1-229x300.jpg\" alt=\"The image is a likeness\" width=\"229\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2466\" class=\"wp-caption-text\">Fresco by Raphael of Plato (left) and Aristotle (right).<\/figcaption><\/figure>\n<p>Western scientific thought began in the ancient city of Athens, Greece. Athens was governed as a democracy, which encouraged individuals to think independently, at a time when most civilizations were ruled by monarchies or military conquerors. Foremost among the early philosopher\/scientists to use empirical thinking was Aristotle, born in 384 BCE. Empiricism emphasizes the value of evidence gained from experimentation and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1729\">observation<\/a>. Aristotle studied under Plato and tutored Alexander the Great. Alexander would later conquer the Persian Empire, and in the process spread Greek culture as far east as India.<\/p>\n<p>Aristotle applied an empirical method of analysis called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1734\">deductive reasoning<\/a>, which applies known principles of thought to establish new ideas or predict new outcomes. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1734\">Deductive reasoning<\/a> starts with generalized principles and logically extends them to new ideas or specific conclusions. If the initial principle is valid, then it is highly likely the conclusion is also valid. An example of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1734\">deductive reasoning<\/a> is if A=B, and B=C, then A=C. Another example is if all birds have feathers, and a sparrow is a bird, then a sparrow must also have feathers. The problem with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1734\">deductive reasoning<\/a> is if the initial principle is flawed, the conclusion will inherit that flaw. Here is an example of a flawed initial principle leading to the wrong conclusion; if all animals that fly are birds, and bats also fly, then bats must also be birds.<\/p>\n<p>This type of empirical thinking contrasts with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1735\">inductive reasoning<\/a>, which begins from new observations and attempts to discern underlying generalized principles. A conclusion made through <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1735\">inductive reasoning<\/a> comes from analyzing measurable evidence, rather making a logical connection. For example, to determine whether bats are birds a scientist might list various characteristics observed in birds\u2013the presence of feathers, a toothless beak, hollow bones, lack of forelegs, and externally laid eggs. Next, the scientist would check whether bats share the same characteristics, and if they do not, draw the conclusion that bats are not birds.<\/p>\n<p>Both types of reasoning are important in science because they emphasize the two most important aspects of science: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1729\">observation<\/a> and inference. Scientists test existing principles to see if they accurately infer or predict their observations. They also analyze new observations to determine if the inferred underlying principles still support them.<\/p>\n<figure id=\"attachment_2467\" aria-describedby=\"caption-attachment-2467\" style=\"width: 193px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Avicenna-1.jpg\"><img class=\"wp-image-31 size-medium\" title=\"Source: \u2018Subtilties of Truth\u2019, 1271\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Avicenna-1-193x300.jpg\" alt=\"The drawing is black and white of a man\" width=\"193\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2467\" class=\"wp-caption-text\">1271 drawing of Avicenna (Ibn Sina). He is among the first to link\u00a0mountains to earthquakes and erosion.<\/figcaption><\/figure>\n<p>Greek culture was spread by Alexander and then absorbed by the Romans, who help further extend Greek knowledge into Europe through their vast infrastructure of roads, bridges, and aqueducts. After the fall of the Roman Empire in 476 CE, scientific progress in Europe stalled. Scientific thinkers of medieval time had such high regard for Aristotle\u2019s wisdom and knowledge they faithfully followed his logical approach to understanding nature for centuries. By contrast, science in the Middle East flourished and grew between 800 and 1450 CE, along with culture and the arts.<\/p>\n<p>Near the end of the medieval <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">period<\/a>, empirical experimentation became more common in Europe. During the Renaissance, which lasted from the 14<sup>th<\/sup> through 17<sup>th<\/sup> centuries, artistic and scientific thought experienced a great awakening. European scholars began to criticize the traditional Aristotelian approach and by the end of the Renaissance <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">period<\/a>, empiricism was poised to become a key component of the scientific revolution that would arise in the 17<sup>th<\/sup> century.<\/p>\n<figure id=\"attachment_2468\" aria-describedby=\"caption-attachment-2468\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Bartolomeu_Velho_1568-1.jpg\"><img class=\"wp-image-32 size-medium\" title=\"Source: Cosmographia, Bartolomeu Velho, 1568\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bartolomeu_Velho_1568-1-300x221.jpg\" alt=\"Earth is at the center.\" width=\"300\" height=\"221\"><\/a><figcaption id=\"caption-attachment-2468\" class=\"wp-caption-text\">Geocentric drawing by Bartolomeu Velho in 1568<\/figcaption><\/figure>\n<p>An early example of how Renaissance scientists began to apply a modern empirical approach is their study of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1253\">solar system<\/a>. In the second century, the Greek astronomer Claudius Ptolemy observed the Sun, Moon, and stars moving across the sky. Applying Aristotelian logic to his astronomical calculations, he deductively reasoned all celestial bodies orbited around the Earth, which was located at the center of the universe. Ptolemy was a highly regarded mathematician, and his mathematical calculations were widely accepted by the scientific community.\u00a0 The view of the cosmos with Earth at its center is called the geocentric model. This geocentric model persisted until the Renaissance <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">period<\/a>, when some revolutionary thinkers challenged the centuries-old <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a>.<\/p>\n<p>By contrast, early Renaissance scholars such as astronomer Nicolaus Copernicus (1473-1543) proposed an alternative explanation for the perceived movement of the Sun, Moon, and stars. Sometime between 1507 and 1515, he provided credible mathematical proof for a radically new model of the cosmos, one in which the Earth and other planets orbited around a centrally located Sun. After the invention of the telescope in 1608, scientists used their enhanced astronomical observations to support this heliocentric, Sun-centered, model.<\/p>\n<figure id=\"attachment_2470\" aria-describedby=\"caption-attachment-2470\" style=\"width: 210px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Galileo_manuscript-1.png\"><img class=\"wp-image-33 size-medium\" title=\"Source: Letter by Galileo, 1609.\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Galileo_manuscript-1-210x300.png\" alt=\"This is a manuscript showing 4 moons of Jupiter.\" width=\"210\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2470\" class=\"wp-caption-text\">Galileo's first mention of moons of Jupiter.<\/figcaption><\/figure>\n<figure id=\"attachment_2469\" aria-describedby=\"caption-attachment-2469\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Copernican_heliocentrism_diagram-2-1.jpg\"><img class=\"wp-image-34 size-medium\" title=\"Source: Nicolaus Copernicus' &quot;De revolutionibus orbium coelestium&quot; 1543\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Copernican_heliocentrism_diagram-2-1-300x275.jpg\" alt=\"The sun is in the center\" width=\"300\" height=\"275\"><\/a><figcaption id=\"caption-attachment-2469\" class=\"wp-caption-text\">Copernicus' heliocentric model<\/figcaption><\/figure>\n<p>Two scientists, Johannes Kepler and Galileo Galilei, are credited with jump-starting the scientific revolution. They accomplished this by building on Copernicus work and challenging long-established ideas about nature and science.<\/p>\n<p>Johannes Kepler (1571-1630) was a German mathematician and astronomer who expanded on the heliocentric model\u2014improving Copernicus\u2019 original calculations and describing planetary motion as elliptical paths. Galileo Galilei (1564 \u2013 1642) was an Italian astronomer who used the newly developed telescope to observe the four largest moons of Jupiter. This was the first piece of direct evidence to contradict the geocentric model, since moons orbiting Jupiter could not also be orbiting Earth.<\/p>\n<p>Galileo strongly supported the heliocentric model and attacked the geocentric model, arguing for a more scientific approach to determine the credibility of an idea. Because of this he found himself at odds with prevailing scientific views and the Catholic Church. In 1633 he was found guilty of heresy and placed under house arrest, where he would remain until his death in 1642.<\/p>\n<p>Galileo is regarded as the first modern scientist because he conducted experiments that would prove or disprove <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1726\">falsifiable<\/a> ideas and based his conclusions on mathematical analysis of quantifiable evidence\u2014a radical departure from the deductive thinking of Greek philosophers such as Aristotle . His methods marked the beginning of a major shift in how scientists studied the natural world, with an increasing number of them relying on evidence and experimentation to form their hypotheses. It was during this revolutionary time that geologists such as James Hutton and Nicolas Steno also made great advances in their scientific fields of study.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-3\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-3\" class=\"h5p-iframe\" data-content-id=\"3\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1.3 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3713\" aria-describedby=\"caption-attachment-3713\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/1.3-Did-I-Get-It.png\"><img class=\"wp-image-35 size-thumbnail\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/1.3-Did-I-Get-It-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3713\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 1.3 via this QR Code.<\/figcaption><\/figure>\n<h2>1.4 Foundations of Modern Geology<\/h2>\n<figure id=\"attachment_2471\" aria-describedby=\"caption-attachment-2471\" style=\"width: 199px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Stenoshark-1.jpg\"><img class=\"wp-image-36 size-medium\" title=\"Source: Nicolas Steno's Elementorum myologi\u00e6 specimen, seu musculi descriptio geometrica : cui accedunt Canis Carchari\u00e6 dissectum caput, et dissectus piscis ex Canum genere, 1667\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Stenoshark-1-199x300.jpg\" alt=\"It shows a shark mouth and several teeth\" width=\"199\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2471\" class=\"wp-caption-text\">Illustration by Steno showing a comparison between fossil and modern shark teeth.<\/figcaption><\/figure>\n<p>As part of the scientific revolution in Europe, modern geologic principles developed in the 17th and 18th centuries. One major contributor was Nicolaus Steno (1638-1686), a Danish priest who studied anatomy and geology. Steno was the first to propose the Earth\u2019s surface could change over time. He suggested sedimentary rocks, such as sandstone and shale, originally formed in horizontal layers with the oldest on the bottom and progressively younger layers on top.<\/p>\n<p>In the 18th century, Scottish naturalist James Hutton (1726\u20131797) studied rivers and coastlines and compared the sediments they left behind to exposed sedimentary rock strata. He hypothesized the ancient rocks must have been formed by processes like those producing the features in the oceans and streams. Hutton also proposed the Earth was much older than previously thought. Modern geologic processes operate slowly. Hutton realized if these processes formed rocks, then the Earth must be very old, possibly hundreds of millions of years old.<\/p>\n<p>Hutton\u2019s idea is called the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">principle of uniformitarianism<\/a> and states that natural processes operate the same now as in the past, i.e. the laws of nature are uniform across space and time. Geologist often state \u201cthe present is the key to the past,\u201d meaning they can understand ancient rocks by studying modern geologic processes.<\/p>\n<figure id=\"attachment_2472\" aria-describedby=\"caption-attachment-2472\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Cuvier_elephant_jaw-1.jpg\"><img class=\"wp-image-37 size-medium\" title=\"Source: Cuvier, 1799\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Cuvier_elephant_jaw-1-300x230.jpg\" alt=\"It shows two views of each jaw.\" width=\"300\" height=\"230\"><\/a><figcaption id=\"caption-attachment-2472\" class=\"wp-caption-text\">Cuvier's comparison of modern elephant and mammoth jaw bones.<\/figcaption><\/figure>\n<p>Prior to the acceptance of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">uniformitarianism<\/a>, scientists such as German geologist Abraham Gottlob Werner (1750-1817) and French anatomist Georges Cuvier (1769-1832) thought rocks and landforms were formed by great catastrophic events. Cuvier championed this view, known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1737\">catastrophism<\/a>, and stated, \u201cThe thread of operation is broken; nature has changed course, and none of the agents she employs today would have been sufficient to produce her former works.\u201d He meant processes that operate today did not operate in the past. Known as the father of vertebrate paleontology, Cuvier made significant contributions to the study of ancient life and taught at Paris\u2019s Museum of Natural History. Based on his study of large vertebrate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a>, he was the first to suggest species could go <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_755\">extinct<\/a>. However, he thought new species were introduced by special creation after catastrophic floods.<\/p>\n<figure id=\"attachment_2492\" aria-describedby=\"caption-attachment-2492\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/Lyell_Principles_frontispiece.jpg\"><img class=\"wp-image-38 size-medium\" title=\"Source: Charles Lyell, Elements of Geology (second American edition, 1857)\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Lyell_Principles_frontispiece-1.jpg\" alt=\"It shows a rudimentary cross section\" width=\"300\" height=\"191\"><\/a><figcaption id=\"caption-attachment-2492\" class=\"wp-caption-text\">Inside cover\u00a0of Lyell's Elements of Geology<\/figcaption><\/figure>\n<p>Hutton\u2019s ideas about <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">uniformitarianism<\/a> and Earth\u2019s age were not well received by the scientific community of his time. His ideas were falling into obscurity when Charles Lyell, a British lawyer and geologist (1797-1875), wrote the <em>Principles of Geology <\/em>in the early 1830s and later, <em><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">Elements<\/a>\u00a0of Geology<\/em>. Lyell\u2019s books promoted Hutton\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">principle of uniformitarianism<\/a>, his studies of rocks and the processes that formed them, and the idea that Earth was possibly over 300 million years old. Lyell and his three-volume <em>Principles of Geology<\/em> had a lasting influence on the geologic community and public at large, who eventually accepted <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">uniformitarianism<\/a> and millionfold age for the Earth. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">principle of uniformitarianism<\/a> became so widely accepted, that geologists regarded catastrophic change as heresy. This made it harder for ideas like the sudden demise of the dinosaurs by asteroid impact to gain traction.<\/p>\n<p>A contemporary of Lyell, Charles Darwin (1809-1882) took <em>Principles of Geology<\/em> on his five-year trip on the HMS Beagle. Darwin used <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">uniformitarianism<\/a> and deep geologic time to develop his initial ideas about evolution. Lyell was one of the first to publish a reference to Darwin\u2019s idea of evolution.<\/p>\n<p>The next big advancement, and perhaps the largest in the history of geology, is the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> and continental drift. Dogmatic acceptance of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1736\">uniformitarianism<\/a> inhibited the progress of this idea, mainly because of the permanency placed on the continents and their positions. Ironically, slow and steady movement of plates would fit well into a uniformitarianism model. However, much time passed and a great deal of scientific resistance had to be overcome before the idea took hold. This happened for several reasons. Firstly, the movement was so slow it was overlooked. Secondly, the best evidence was hidden under the ocean. Finally, the accepted theories were anchored by a large amount of inertia. Instead of being bias free, scientists resisted and ridiculed the emerging idea of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a>. This example of dogmatic thinking is still to this day a tarnish on the geoscience community.<\/p>\n<figure id=\"attachment_2511\" aria-describedby=\"caption-attachment-2511\" style=\"width: 244px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/John_Tuzo_Wilson_in_1992-2.jpg\"><img class=\"size-medium wp-image-39\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/John_Tuzo_Wilson_in_1992-2-244x300.jpg\" alt=\"He is an older man in this 1992 image.\" width=\"244\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2511\" class=\"wp-caption-text\">J. Tuzo Wilson<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">Plate tectonics<\/a> is most commonly attributed to Alfred Wegener, the first scientist to compile a large data set supporting the idea of continents shifting places over time. He was mostly ignored and ridiculed for his ideas, but later workers like Marie Tharp, Bruce Heezen, Harry Hess, Laurence Morley, Frederick Vine, Drummond Matthews, Kiyoo Wadati, Hugo Benioff, Robert Coats, and J. Tuzo Wilson benefited from advances in sub-sea technologies. They discovered, described, and analyzed new features like the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridge<\/a>, alignment of earthquakes, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1709\">magnetic striping<\/a>. Gradually these scientists introduced a paradigm shift that revolutionized geology into the science we know today.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-4\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-4\" class=\"h5p-iframe\" data-content-id=\"4\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1.4 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3712\" aria-describedby=\"caption-attachment-3712\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/1.4-Did-I-Get-It.png\"><img class=\"wp-image-40 size-thumbnail\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/1.4-Did-I-Get-It-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3712\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 1.4 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">1.5 The Study of Geology<br \/>\n<\/span><\/h2>\n<figure id=\"attachment_2475\" aria-describedby=\"caption-attachment-2475\" style=\"width: 225px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/DSC00832-1.jpg\"><img class=\"wp-image-41 size-medium\" title=\"By Mason Chuang\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/DSC00832-1-225x300.jpg\" alt=\"The students are on the red rock\" width=\"225\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2475\" class=\"wp-caption-text\">A class looks at rocks in Zion National Park.<\/figcaption><\/figure>\n<p>Geologists apply the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a> to learn about Earth\u2019s materials and processes. Geology plays an important role in society; its principles are essential to locating, extracting, and managing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1738\">natural resources<\/a>; evaluating environmental impacts of using or extracting these resources; as well as understanding and mitigating the effects of natural hazards.<\/p>\n<p>Geology often applies information from physics and chemistry to the natural world, like understanding the physical forces in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_246\">landslide<\/a> or the chemical interaction between water and rocks. The term comes from the Greek word <em>geo<\/em>, meaning Earth, and <em>logos<\/em>, meaning to think or reckon with.<\/p>\n<h3>1.5.1 Why Study Geology?<\/h3>\n<figure id=\"attachment_2476\" aria-describedby=\"caption-attachment-2476\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/16.1_Hoover_Dam_Colorado_River-1.jpg\"><img class=\"size-medium wp-image-42\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1_Hoover_Dam_Colorado_River-1-300x200.jpg\" alt=\"The dam has a large lake behind it\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-2476\" class=\"wp-caption-text\">Hoover Dam provides hydroelectric energy and stores water for southern Nevada.<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\">Geology plays a key role in how we use <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1738\">natural resources<\/a>\u2014any naturally occurring material that can be extracted from the Earth for economic gain. Our developed modern society, like all societies before it, is dependent on geologic resources. Geologists are involved in extracting fossil fuels, such as coal and petroleum; metals such as copper, aluminum, and iron; and water resources in streams and underground reservoirs inside <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">soil<\/a> and rocks. They can help conserve our planet\u2019s finite supply of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources, like petroleum, which are fixed in quantity and depleted by consumption. Geologists can also help manage <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> resources that can be replaced or regenerated, such as solar or wind energy, and timber.<\/span><\/p>\n<figure id=\"attachment_2477\" aria-describedby=\"caption-attachment-2477\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/16.2_Castle_Gate_Power_Plant_Utah_2007-1.jpg\"><img class=\"size-medium wp-image-43\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.2_Castle_Gate_Power_Plant_Utah_2007-1-300x188.jpg\" alt=\"The power plant has smoke coming from it\" width=\"300\" height=\"188\"><\/a><figcaption id=\"caption-attachment-2477\" class=\"wp-caption-text\">Coal power plant in Helper, Utah.<\/figcaption><\/figure>\n<p>Resource extraction and usage impacts our environment, which can negatively affect human health. For example, burning fossil fuels\u00a0releases chemicals into the air that are unhealthy for humans, especially children. Mining activities can release toxic heavy metals, such as lead and mercury, into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">soil<\/a> and waterways. Our choices will have an effect on Earth\u2019s environment for the foreseeable future. Understanding the remaining quantity, extractability, and renewability of geologic resources will help us better sustainably manage those resources.<\/p>\n<figure id=\"attachment_2478\" aria-describedby=\"caption-attachment-2478\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Liquefaction_at_Niigata-1.jpg\"><img class=\"size-medium wp-image-44\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Liquefaction_at_Niigata-1-300x178.jpg\" alt=\"Buildings toppled from liquefaction during a 7.5 magnitude earthquake in Japan.\" width=\"300\" height=\"178\"><\/a><figcaption id=\"caption-attachment-2478\" class=\"wp-caption-text\">Buildings toppled from liquefaction during a 7.5 magnitude earthquake in Japan.<\/figcaption><\/figure>\n<p>Geologists also study natural hazards created by geologic processes. Natural hazards are phenomena that are potentially dangerous to human life or property. No place on Earth is completely free of natural hazards, so one of the best ways people can protect themselves is by understanding geology. Geology can teach people about the natural hazards in an area and how to prepare for them. Geologic hazards include <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_246\">landslides<\/a>, earthquakes, tsunamis, floods, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> eruptions, and sea-level rise.<\/p>\n<figure id=\"attachment_2479\" aria-describedby=\"caption-attachment-2479\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Crater_lake_oregon-1.jpg\"><img class=\"wp-image-45 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Crater_lake_oregon-1-300x200.jpg\" alt=\"The mountain has a large hole in the center that is filled with the lake.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-2479\" class=\"wp-caption-text\">Oregon's Crater Lake was formed about 7700 years ago after the eruption of Mount Mazama.<\/figcaption><\/figure>\n<p>Finally, geology is where other scientific disciplines intersect in the concept known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1748\">Earth System Science<\/a>. In science, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1742\">system<\/a> is a group of interactive objects and processes. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1748\">Earth System Science<\/a> views the entire planet as a combination of systems that interact with each other via complex relationships. This geology textbook provides an introduction to science in general and will often reference other scientific disciplines.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1748\">Earth System Science<\/a> includes five basic systems (or spheres), the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1743\">Geosphere<\/a> (the solid body of the Earth), the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">Atmosphere<\/a> (the gas envelope surrounding the Earth), the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1744\">Hydrosphere<\/a> (water in all its forms at and near the surface of the Earth), the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1746\">Cryosphere<\/a> (frozen water part of Earth), and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1747\">Biosphere<\/a> (life on Earth in all its forms and interactions, including humankind).<\/p>\n<p><span style=\"font-weight: 400\">Rather than viewing geology as an isolated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1742\">system<\/a>, earth <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1742\">system<\/a> scientists study how geologic processes shape not only the world, but all the spheres it contains. They study how these multidisciplinary spheres relate, interact, and change in response to natural cycles and human-driven forces. They use <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>\u00a0from physics, chemistry, biology, meteorology, environmental science, zoology, hydrology, and many other sciences.<br \/>\n<\/span><\/p>\n<h3><b>1.5.2 Rock Cycle<\/b><\/h3>\n<figure id=\"attachment_2480\" aria-describedby=\"caption-attachment-2480\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Fig-6-1.jpg\"><img class=\"size-medium wp-image-46\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Fig-6-1-300x278.jpg\" alt=\"The rock cycle shows how different rock groups are interconnected. Metamorphic rocks can come from adding heat and\/or pressure to other metamorphic rock or sedimentary or igneous rocks\" width=\"300\" height=\"278\"><\/a><figcaption id=\"caption-attachment-2480\" class=\"wp-caption-text\">Rock cycle showing the five materials (such as igneous rocks and sediment) and the processes by which one changes into another (such as weathering). (Source: Peter Davis)<\/figcaption><\/figure>\n<p>The most fundamental view of Earth materials is the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1749\">rock cycle<\/a>, which describes the major materials that comprise the Earth, the processes that form them, and how they relate to each other. It usually begins with hot molten liquid rock called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">Magma<\/a> forms under the Earth\u2019s surface in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">Lava<\/a> is molten rock that erupts onto the Earth\u2019s surface. When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a> cools, it solidifies by a process called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1752\">crystallization<\/a> in which minerals grow within the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a>. The rocks resulting rocks are igneous rocks. I<em>gnis<\/em> is Latin for fire.<\/p>\n<figure id=\"attachment_2481\" aria-describedby=\"caption-attachment-2481\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Raindrop_impressions_mcr1-1.jpg\"><img class=\"size-medium wp-image-47\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Raindrop_impressions_mcr1-1-300x200.jpg\" alt=\"This grey rock has round circles left by raindrops\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-2481\" class=\"wp-caption-text\">Mississippian raindrop impressions over wave ripples from Nova Scotia.<\/figcaption><\/figure>\n<p>Igneous rocks, as well as other types of rocks, on Earth\u2019s surface are exposed to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1755\">erosion<\/a>, which produces <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">Weathering<\/a> is the physical and chemical breakdown of rocks into smaller fragments. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1755\">Erosion<\/a> is the removal of those fragments from their original location. The broken-down and transported fragments or grains are considered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>, such as gravel, sand, silt, and clay. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> may be transported by streams and rivers, ocean currents, glaciers, and wind.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">Sediments<\/a> come to rest in a process known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1757\">deposition<\/a>. As the deposited <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> accumulate\u2014often under water, such as in a shallow marine environment\u2014the older <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> get buried by the new deposits. The deposits are compacted by the weight of the overlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> and individual grains are cemented together by minerals in groundwater. These processes of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1758\">compaction<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1759\">cementation<\/a> are called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1760\">lithification<\/a>. Lithified <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> are considered a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1761\">sedimentary rock<\/a>, such as sandstone and shale. Other sedimentary rocks are made by direct chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> of minerals rather than eroded <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>, and are known as chemical sedimentary rocks.<\/p>\n<figure id=\"attachment_2482\" aria-describedby=\"caption-attachment-2482\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/06.2-15-Mt-Blaca-Migmatite-1.jpg\"><img class=\"wp-image-48 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/06.2-15-Mt-Blaca-Migmatite-1-300x225.jpg\" alt=\"Swirling bands of light and dark minerals.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-2482\" class=\"wp-caption-text\">Migmatite, a rock which was partially molten. (Source: Peter Davis)<\/figcaption><\/figure>\n<p>Pre-existing rocks may be transformed into a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1762\">metamorphic rock<\/a>; <em>meta- <\/em>means change and <em>-morphos<\/em> means form or shape. When rocks are subjected to extreme increases in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> or pressure, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> crystals are enlarged or altered into entirely new minerals\u00a0with similar chemical make up. High temperatures and pressures occur in rocks buried deep within the Earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> or that come into contact with hot <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a>. If the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> and pressure conditions melt the rocks to create <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a>, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1749\">rock cycle<\/a> begins anew with the creation of new rocks.<\/p>\n<h3><b>1.5.3 Plate Tectonics and Layers of Earth<\/b><\/h3>\n<figure id=\"attachment_2516\" aria-describedby=\"caption-attachment-2516\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Plates_tect2_en.svg_-2.png\"><img class=\"size-medium wp-image-49\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Plates_tect2_en.svg_-2-300x205.png\" alt=\"There are about 10 major plates\" width=\"300\" height=\"205\"><\/a><figcaption id=\"caption-attachment-2516\" class=\"wp-caption-text\">Map of the major plates and their motions along boundaries.<\/figcaption><\/figure>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a><\/strong> is the fundamental unifying principle of geology and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1749\">rock cycle<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">Plate tectonics<\/a> describes how Earth\u2019s layers move relative to each other, focusing on the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> or lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> of the outer layer. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">Tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>\u00a0float, collide, slide past each other, and split apart on an underlying mobile layer called the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a><\/strong>. Major landforms are created at the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> boundaries, and rocks within the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> move through the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1749\">rock cycle<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">Plate tectonics<\/a> is discussed in more detail in <a href=\"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/2-plate-tectonics\/\" target=\"_blank\" rel=\"noopener\">Chapter 2<\/a>.<\/p>\n<figure id=\"attachment_2513\" aria-describedby=\"caption-attachment-2513\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/MohoDepth-1.png\"><img class=\"wp-image-50 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MohoDepth-1-300x167.png\" alt=\"Places with mountain building have a deeper moho.\" width=\"300\" height=\"167\"><\/a><figcaption id=\"caption-attachment-2513\" class=\"wp-caption-text\">The global map of the depth of the moho.<\/figcaption><\/figure>\n<p>Earth\u2019s three main geological layers can be categorized by chemical composition or the chemical makeup: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> is the outermost layer and composed\u00a0of mostly silicon, oxygen, aluminum, iron, and magnesium. There are two types, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental crust<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic crust<\/a>. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">Continental crust<\/a><\/strong> is about 50 km (30 mi) thick, composed of low-density igneous and sedimentary rocks, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">Oceanic crust<\/a><\/strong> is approximately 10 km (6 mi) thick and made of high-density igneous <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1013\">basalt<\/a>-type rocks. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">Oceanic crust<\/a> makes up most of the ocean floor, covering about 70% of the planet. Tectonic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>\u00a0are made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> and a portion the upper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>, forming a rigid physical layer called the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>.<\/p>\n<figure id=\"attachment_2512\" aria-describedby=\"caption-attachment-2512\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Earth-cutaway-schematic-english.svg_-1.png\"><img class=\"size-medium wp-image-51\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Earth-cutaway-schematic-english.svg_-1-300x211.png\" alt=\"The crust and lithosphere are on the outside of the Earth and are thin. Below the crust is the mantle and core. Below the lithosphere is the asthenosphere.\" width=\"300\" height=\"211\"><\/a><figcaption id=\"caption-attachment-2512\" class=\"wp-caption-text\">The layers of the Earth. Physical layers include lithosphere and asthenosphere; chemical layers are crust, mantle, and core.<\/figcaption><\/figure>\n<p>The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a><\/strong>, the largest chemical layer by volume, lies below the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> and extends down to about 2,900 km (1,800 mi) below the Earth\u2019s surface. The mostly solid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> is made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1666\">peridotite<\/a>, a high-density composed of silica, iron, and magnesium. The upper part of mantel is very hot and flexible, which allows the overlying tectonic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> to float and move about on it. Under the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> is the Earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a>, which is 3,500 km (2,200 mi) thick and made of iron and nickel. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a> consists of two parts, a liquid <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1673\">outer core<\/a><\/strong> and solid <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1674\">inner core<\/a><\/strong>. Rotations within the solid and liquid metallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a> generate Earth\u2019s magnetic field (see figure).<\/p>\n<h3><b>1.5.4 Geologic Time and Deep Time<\/b><\/h3>\n<blockquote>\n<figure id=\"attachment_2486\" aria-describedby=\"caption-attachment-2486\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/GeologicClock.png\"><img class=\"size-medium wp-image-52\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/GeologicClock-300x288.png\" alt=\"The circle starts at 4.6 billion years ago, then loops around to zero.\" width=\"300\" height=\"288\"><\/a><figcaption id=\"caption-attachment-2486\" class=\"wp-caption-text\">Geologic time on Earth, represented circularly, to show the individual time divisions and important events. Ga=billion years ago, Ma=million years ago.<\/figcaption><\/figure>\n<p>\u201cThe result, therefore, of our present enquiry is, that we find no vestige of a beginning; no prospect of an end.\u201d (James Hutton, 1788)<\/p><\/blockquote>\n<p>One of the early pioneers of geology, James Hutton, wrote this about the age of the Earth after many years of geological study. Although he wasn\u2019t exactly correct\u2014there is a beginning and will be an end to planet Earth\u2014Hutton was expressing the difficulty humans have in perceiving the vastness of geological time. Hutton did not assign an age to the Earth, although he was the first to suggest the planet was very old.<br \/>\nToday we know Earth is approximately 4.54 \u00b1 0.05 billion years old. This age was first calculated by Caltech professor Clair Patterson in 1956, who measured the half-lives of lead <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1779\">isotopes<\/a>\u00a0to radiometrically date a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1254\">meteorite<\/a> recovered in Arizona. Studying geologic time, also known as deep time, can help us overcome a perspective of Earth that is limited to our short lifetimes. Compared to the geologic scale, the human lifespan is very short, and we struggle to comprehend the depth of geologic time and slowness of geologic processes. For example, the study of earthquakes only goes back about 100 years; however, there is geologic evidence of large earthquakes occurring thousands of years ago. And scientific evidence indicates earthquakes will continue for many centuries into the future.<\/p>\n<figure id=\"attachment_2492\" aria-describedby=\"caption-attachment-2492\" style=\"width: 793px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/17.18_Geologic_Time_Scale_with_years-1.jpg\"><img class=\"wp-image-53 size-large\" title=\"Source: Belinda Madsen, Salt Lake Community College\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/17.18_Geologic_Time_Scale_with_years-1-793x1024.jpg\" alt=\"The Geologic Time Scale with an age of each unit shown by a scale\" width=\"793\" height=\"1024\"><\/a><figcaption id=\"caption-attachment-2492\" class=\"wp-caption-text\">Geologic time scale showing time period names and ages. (Source: Belinda Madsen)<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1242\">Eons<\/a>\u00a0are the largest divisions of time, and from oldest to youngest are named <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1255\">Hadean<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1257\">Archean<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1261\">Proterozoic<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1269\">Phanerozoic<\/a>. The three oldest <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1242\">eons<\/a> are sometimes collectively referred to as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1270\">Precambrian<\/a> time.<\/p>\n<p>Life first appeared more than 3,800 million of years ago (Ma). From 3,500 Ma to 542 Ma, or 88% of geologic time, the predominant life forms were single-celled organisms such as bacteria. More complex organisms appeared only more recently, during the current <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1269\">Phanerozoic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1242\">Eon<\/a>, which includes the last 542 million years or 12% of geologic time.<\/p>\n<p>The name <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1269\">Phanerozoic<\/a> comes from <em>phaneros<\/em>, which means visible, and <em>zoic<\/em>, meaning life. This <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1242\">eon<\/a> marks the proliferation of multicellular animals with hard body parts, such as shells, which are preserved in the geological record as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a>. Land-dwelling animals have existed for 360 million years, or 8% of geologic time. The demise of the dinosaurs and subsequent rise of mammals occurred around 65 Ma, or 1.5% of geologic time. Our human ancestors belonging to the genus <em>Homo<\/em> have existed since approximately 2.2 Ma\u20140.05% of geological time or just 1\/2,000th the total age of Earth.<\/p>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1269\">Phanerozoic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1242\">Eon<\/a> is divided into three <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1243\">eras<\/a>: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1271\">Paleozoic<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_479\">Mesozoic<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_488\">Cenozoic<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1271\">Paleozoic<\/a> means <em>ancient life<\/em>, and organisms of this era included invertebrate animals, fish, amphibians, and reptiles. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_479\">Mesozoic<\/a> (<em>middle life<\/em>) is popularly known as the Age of Reptiles and is characterized by the abundance of dinosaurs, many of which evolved into birds. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1275\">mass extinction<\/a> of the dinosaurs and other apex predator reptiles marked the end of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_479\">Mesozoic<\/a> and beginning of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_488\">Cenozoic<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_488\">Cenozoic<\/a> means <em>new life<\/em> and is also called the Age of Mammals, during which mammals evolved to become the predominant land-dwelling animals. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">Fossils<\/a>\u00a0of early humans, or hominids, appear in the rock record only during the last few million years of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_488\">Cenozoic<\/a>. The geologic time scale, geologic time, and geologic history are discussed in more detail in\u00a0chapters <a href=\"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/7-geologic-time\/\">7<\/a> and <a href=\"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/8-earth-history\/\">8<\/a>.<\/p>\n<h3>1.5.5 \u00a0 The Geologist\u2019s Tools<\/h3>\n<figure id=\"attachment_2488\" aria-describedby=\"caption-attachment-2488\" style=\"width: 222px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Archaeopteryx_lithographica_Berlin_specimen.jpg\"><img class=\"size-medium wp-image-54\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Archaeopteryx_lithographica_Berlin_specimen-222x300.jpg\" alt=\"The fossil has bird and dinosaur features.\" width=\"222\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2488\" class=\"wp-caption-text\">Iconic Archaeopteryx lithographica fossil from Germany.<\/figcaption><\/figure>\n<p>In its simplest form, a geologist\u2019s tool may be a rock hammer used for sampling a fresh surface of a rock. A basic tool set for fieldwork might also include:<\/p>\n<ul>\n<li>Magnifying lens for looking at mineralogical details<\/li>\n<li>Compass for measuring the orientation of geologic features<\/li>\n<li>Map for documenting the local distribution of rocks and minerals<\/li>\n<li>Magnet for identifying magnetic minerals like magnetite<\/li>\n<li>Dilute <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a> of hydrochloric acid to identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a>-containing minerals like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> or limestone.<\/li>\n<\/ul>\n<p>In the laboratory, geologists use optical microscopes to closely examine rocks and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">soil<\/a> for <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> composition and grain size. Laser and mass spectrometers precisely measure the chemical composition and geological age of minerals. Seismographs\u00a0record and locate earthquake activity, or when used in conjunction with ground penetrating radar, locate objects buried beneath the surface of the earth. Scientists apply computer simulations to turn their collected data into testable, theoretical models. Hydrogeologists drill wells to sample and analyze underground water quality and availability. Geochemists use scanning electron microscopes to analyze minerals at the atomic level, via x-rays. Other geologists use gas chromatography to analyze liquids and gases trapped in glacial ice or rocks.<\/p>\n<p>Technology provides new tools for scientific <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1729\">observation<\/a>, which leads to new evidence that helps scientists revise and even refute old ideas. Because the ultimate technology will never be discovered, the ultimate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1729\">observation<\/a> will never be made. And this is the beauty of science\u2014it is ever-advancing and always discovering something new.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-5\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-5\" class=\"h5p-iframe\" data-content-id=\"5\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1.5 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3711\" aria-describedby=\"caption-attachment-3711\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/1.5-Did-I-Get-It.png\"><img class=\"size-thumbnail wp-image-55\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/1.5-Did-I-Get-It-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3711\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 1.5 via this QR Code.<\/figcaption><\/figure>\n<h2><strong>1.6 Science Denial and Evaluating Sources<\/strong><\/h2>\n<p><iframe id='oembed-2' title=\"Science in America - Neil deGrasse Tyson\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/8MqTOEospfo?feature=oembed&rel=0\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<figure id=\"attachment_3710\" aria-describedby=\"caption-attachment-3710\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Science-in-America-YouTube.png\"><img class=\"size-thumbnail wp-image-56\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Science-in-America-YouTube-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3710\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this YouTube video via this QR Code.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2489\" aria-describedby=\"caption-attachment-2489\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Anti-EvolutionLeague.jpg\"><img class=\"size-medium wp-image-57\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Anti-EvolutionLeague-300x223.jpg\" alt=\"There are several people around a sign\" width=\"300\" height=\"223\"><\/a><figcaption id=\"caption-attachment-2489\" class=\"wp-caption-text\">Anti-evolution league at the infamous Tennessee v. Scopes trial.<\/figcaption><\/figure>\n<p>Introductory science courses usually deal with accepted scientific <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> and do not include opposing ideas, even though these alternate ideas may be credible. This makes it easier for students to understand the complex material. Advanced students will encounter more controversies as they continue to study their discipline.<\/p>\n<p><span style=\"font-weight: 400\">Some groups of people argue that some established scientific theories are wrong, not based on their scientific merit but rather on the ideology of the group. This section focuses on how to identify evidence based information and differentiate it from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1727\">pseudoscience<\/a>.<br \/>\n<\/span><\/p>\n<h3>1.6.1 Science Denial<\/h3>\n<figure id=\"attachment_2490\" aria-describedby=\"caption-attachment-2490\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/MarchForScience2017-scaled.jpg\"><img class=\"size-medium wp-image-2490\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MarchForScience2017-scaled-1.jpg\" alt=\"There are many people on the steps of the capitol.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-2490\" class=\"wp-caption-text\">2017 March for Science in Salt Lake City. This and other similar marches were in response to funding cuts and anti-science rhetoric.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1763\">Science denial<\/a> happens when people argue that established scientific theories are wrong, not based on scientific merit but rather on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1723\">subjective<\/a> ideology\u2014such as for social, political, or economic reasons. Organizations and people use <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1763\">science denial<\/a> as a rhetorical argument against issues or ideas they oppose. Three examples of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1763\">science denial<\/a> versus science are: 1) teaching evolution in public schools, 2) linking tobacco smoke to cancer, and 3) linking human activity to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> change. Among these, denial of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> change is strongly connected with geology. A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> denier specifically denies or doubts the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> conclusions of geologists and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> scientists.<\/p>\n<figure id=\"attachment_2491\" aria-describedby=\"caption-attachment-2491\" style=\"width: 263px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/1.4_pillars_Science-Denial_NCSE.png\"><img class=\"size-medium wp-image-59\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/1.4_pillars_Science-Denial_NCSE-263x300.png\" alt=\"Shows three pillars labeled &quot;Undermine the Science&quot;, &quot;Claim the Result is Evil&quot;, and &quot;Demand Equal Time&quot;.\" width=\"263\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2491\" class=\"wp-caption-text\">Three false rhetorical arguments of science denial (Source: National Center for Science Education)<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1763\">Science denial<\/a> generally uses three false arguments. The first argument tries to undermine the credibility of the scientific conclusion by claiming the research methods are flawed or the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> is not universally accepted\u2014the science is unsettled. The notion that scientific ideas are not absolute creates doubt for non-scientists; however, a lack of universal truths should not be confused with scientific uncertainty. Because science is based on falsfiabiity, scientists avoid claiming universal truths and use language that conveys uncertainty. This allows scientific ideas to change and evolve as more evidence is uncovered.<\/p>\n<p>The second argument claims the researchers are not <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> and motivated by an ideology or economic agenda. This is an <em>ad hominem<\/em> argument in which a person\u2019s character is attacked instead of the merit of their argument. They claim results have been manipulated so researchers can justify asking for more funding. They claim that because the researchers are funded by a federal grant, they are using their results to lobby for expanded government regulation.<\/p>\n<p>The third argument is to demand a balanced view, equal time in media coverage and educational curricula, to engender the false illusion of two equally valid arguments. Science deniers frequently demand equal coverage of their proposals, even when there is little scientific evidence supporting their ideology. For example, science deniers might demand religious explanations be taught as an alternative to the well-established <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of evolution <span style=\"font-weight: 400\"> [zotpressInText item=\"{X9U8B54N},{W934C3CR}\" format=\"%num%\" brackets=\"yes\"]<\/span>. Or that all possible causes of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> change be discussed as equally probable, regardless of the body of evidence. Conclusions derived using the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a> should not be confused with those based on ideologies.<\/p>\n<p>Furthermore, conclusions about nature derived from ideologies have no place in science research and education. For example, it would be inappropriate to teach the flat earth model in a modern geology course because this idea has been disproved by the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a>. Unfortunately, widespread scientific illiteracy allows these arguments to be used to suppress scientific knowledge and spread misinformation.<\/p>\n<p><span style=\"font-weight: 400\">The formation of new conclusions based on the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a> is the only way to change scientific conclusions. We wouldn't teach Flat Earth geology along with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> because Flat Earthers don't follow the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a>. The fact that scientists avoid universal truths and change their ideas as more evidence is uncovered shouldn't be seen as meaning that the science is unsettled. Because of widespread scientific illiteracy, these arguments are used by those who wish to suppress\u00a0science and misinform the general public.<\/span><\/p>\n<figure id=\"attachment_2492\" aria-describedby=\"caption-attachment-2492\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Cancer_smoking_lung_cancer_correlation_from_NIH.svg_.png\"><img class=\"wp-image-60 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Cancer_smoking_lung_cancer_correlation_from_NIH.svg_-300x293.png\" alt=\"The lines are similar when comparing smoking and cancer\" width=\"300\" height=\"293\"><\/a><figcaption id=\"caption-attachment-2492\" class=\"wp-caption-text\">The lag time between cancer after smoking, plus the ethics of running human trials, delayed the government in taking action against tobacco.<\/figcaption><\/figure>\n<p>In a classic case of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1763\">science denial<\/a>, beginning in the 1960s and for the next three decades, the tobacco industry and their scientists used rhetorical arguments to deny a connection between tobacco usage and cancer. Once it became clear scientific studies overwhelmingly found that using tobacco dramatically increased a person's likelihood of getting cancer, their next strategy was to create a sense of doubt about on the science. The tobacco industry suggested the results were not yet fully understood and more study was needed. They used this doubt to lobby for delaying legislative action that would warn consumers of the potential health hazards <span style=\"font-weight: 400\">[zotpressInText item=\"{X9U8B54N},{CBD5438R}\" format=\"%num%\" brackets=\"yes\"]<\/span>. This same tactic is currently being employed by those who deny the significance of human involvement in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> change.<\/p>\n<h3><strong>1.6.2 Evaluating Sources of Information<\/strong><\/h3>\n<figure id=\"attachment_2493\" aria-describedby=\"caption-attachment-2493\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Cumulative_induced_seismicity.png\"><img class=\"size-medium wp-image-61\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Cumulative_induced_seismicity-300x228.png\" alt=\"There is a large spike in earthquakes\" width=\"300\" height=\"228\"><\/a><figcaption id=\"caption-attachment-2493\" class=\"wp-caption-text\">This graph shows earthquake data. To call this data induced, due to fracking, would be an interpretation.<\/figcaption><\/figure>\n<p>In the age of the internet, information is plentiful. Geologists, scientists, or anyone exploring scientific inquiry must discern valid sources of information from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1727\">pseudoscience<\/a> and misinformation. This evaluation is especially important in scientific research because scientific knowledge is respected for its reliability. Textbooks such as this one can aid this complex and crucial task. At its roots, quality information comes from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a>, beginning with the empirical thinking of Aristotle. The application of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a> helps produce unbiased results. A valid inference or interpretation is based on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> evidence or data. Credible data and inferences are clearly labeled, separated, and differentiated. Anyone looking over the data can understand how the author\u2019s conclusion was derived or come to an alternative conclusion. Scientific procedures are clearly defined so the investigation can be replicated to confirm the original results or expanded further to produce new results. These measures make a scientific inquiry valid and its use as a source reputable. Of course, substandard work occasionally slips through and retractions are published from time to time. An infamous article linking the MMR vaccine to autism appeared in the highly reputable journal <em>Lancet<\/em> in 1998. Journalists discovered the author had multiple conflicts of interest and fabricated data, and the article was retracted in 2010.<\/p>\n<figure id=\"attachment_2494\" aria-describedby=\"caption-attachment-2494\" style=\"width: 100px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/GSA_logo3R_web100.gif\"><img class=\"wp-image-62 size-full\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/GSA_logo3R_web100.gif\" alt=\"\" width=\"100\" height=\"111\"><\/a><figcaption id=\"caption-attachment-2494\" class=\"wp-caption-text\">Logo for The Geological Society of America, one of the leading geoscience organizations. They also publish GSA Bulletin, a reputable geology journal.<\/figcaption><\/figure>\n<p>In addition to methodology, data, and results, the authors of a study should be investigated. When looking into any research, the author(s) should be investigated. An author\u2019s credibility is based on multiple factors, such as having a degree in a relevant topic or being funded from an unbiased source.<\/p>\n<p>The same rigor should be applied to evaluating the publisher, ensuring the results reported come from an unbiased process. The publisher should be easy to discover. Good publishers will show the latest papers in the journal and make their contact information and identification clear.\u00a0 Reputable journals show their <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1732\">peer review<\/a> style.\u00a0 Some journal are predatory, where they use unexplained and unnecessary fees to submit and access journals. Reputable journals have recognizable editorial boards. Often, a reliable journal will associate with a trade, association, or recognized open source initiative.<\/p>\n<p>One of the hallmarks of scientific research is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1732\">peer review<\/a>. \u00a0Research should be transparent to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1732\">peer review<\/a>. This allows the scientific community to reproduce experimental results, correct and retract errors, and validate theories. This allows reproduction of experimental results, corrections of errors, and proper justification of the research to experts.<\/p>\n<p>Citation is not only imperative to avoid plagiarism, but also allows readers to investigate an author\u2019s line of thought and conclusions. When reading scientific works, it is important to confirm the citations are from reputable scientific research. Most often, scientific citations are used to reference paraphrasing rather than quotes. The number of times a work is cited is said to measure of the influence an investigation has within the scientific community, although this technique is inherently biased.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-6\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-6\" class=\"h5p-iframe\" data-content-id=\"6\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1.6 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3709\" aria-describedby=\"caption-attachment-3709\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/1.6-Did-I-Get-It.png\"><img class=\"size-thumbnail wp-image-63\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/1.6-Did-I-Get-It-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3709\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 1.6 via this QR Code.<\/figcaption><\/figure>\n<h2>Summary<\/h2>\n<p>Science is a process, with no beginning and no end. Science is never finished because a full truth can never be known. However, science and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1728\">scientific method<\/a> are the best way to understand the universe we live in. Scientists draw conclusions based on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1722\">objective<\/a> evidence; they consolidate these conclusions into unifying models. Geologists likewise understand studying the Earth is an ongoing process, beginning with James Hutton who declared the Earth has \u201c\u2026no vestige of a beginning, no prospect of an end.\u201d Geologists explore the 4.5 billion-year history of Earth, its resources, and its many hazards. From a larger viewpoint, geology can teach people how to develop credible conclusions, as well as identify and stop misinformation.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this chapter.<\/h3>\n<div id=\"h5p-7\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-7\" class=\"h5p-iframe\" data-content-id=\"7\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Chapter 1 Review\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3708\" aria-describedby=\"caption-attachment-3708\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ch.1-Review.png\"><img class=\"size-thumbnail wp-image-64\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.1-Review-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3708\" class=\"wp-caption-text\">If you using the printed version of this OER, access the review quiz for Chapter 1 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">References<\/span><\/h2>\n<div class=\"csl-bib-body\">\n<ol>\n<li class=\"csl-entry\">Adams, F.D., 1954, The birth and development of the geological sciences<\/li>\n<li class=\"csl-entry\">Alfe, D., Gillan, M.J., and Price, G.D., 2002, Composition and temperature of the Earth\u2019s core constrained by combining ab initio calculations and seismic data: Earth Planet. Sci. Lett., v. 195, no. 1, p. 91\u201398.<\/li>\n<li class=\"csl-entry\">Alkin, M.C., 2004, Evaluation Roots: Tracing theorists\u2019 views and influences: SAGE.<\/li>\n<li class=\"csl-entry\">Beckwith, C., 2013, How western Europe developed a full scientific method: Berfrois.<\/li>\n<li class=\"csl-entry\">Birch, F., 1952, Elasticity and constitution of the Earth\u2019s interior: J. Geophys. Res., v. 57, no. 2, p. 227\u2013286., doi: <a href=\"https:\/\/doi.org\/10.1029\/JZ057i002p00227\">10.1029\/JZ057i002p00227<\/a>.<\/li>\n<li class=\"csl-entry\">Bocking, S., 2004, Nature\u2019s experts: science, politics, and the environment: Rutgers University Press.<\/li>\n<li class=\"csl-entry\">Chamberlin, T.C., 1890, The method of multiple working hypotheses: Science, v. 15, no. 366, p. 92\u201396.<\/li>\n<li class=\"csl-entry\">Cohen, H.F., 2010, How modern science came into the world: Four civilizations, one 17th-century breakthrough: Amsterdam University Press.<\/li>\n<li class=\"csl-entry\">Darwin, C., 1846, Geological Observations on South America: Being the Third Part of the Geology of the Voyage of the Beagle, Under the Command of Capt. Fitzroy, R.N. During the Years 1832 to 1836: Smith, Elder and Company.<\/li>\n<li class=\"csl-entry\">Drake, S., 1990, Galileo: Pioneer Scientist: University of Toronto Press.<\/li>\n<li class=\"csl-entry\">Engdahl, E.R., Flynn, E.A., and Masse, R.P., 1974, Differential PkiKP travel times and the radius of the core: Geophysical J Royal Astro Soc, v. 40, p. 457\u2013463.<\/li>\n<li class=\"csl-entry\">Everitt, A., 2016, The Rise of Athens: The Story of the World\u2019s Greatest Civilization:<\/li>\n<li class=\"csl-entry\">Goldstein, B.R., 2002, Copernicus and the origin of his heliocentric system: Journal for the History of Astronomy, v. 33, p. 219\u2013235.<\/li>\n<li class=\"csl-entry\">Goldsworthy, A.K., 2011, The complete Roman army: Thames &amp; Hudson.<\/li>\n<li class=\"csl-entry\">Hans Wedepohl, K., 1995, The composition of the continental crust: Geochim. Cosmochim. Acta, v. 59, no. 7, p. 1217\u20131232.<\/li>\n<li class=\"csl-entry\">Heilbron, J.L., 2012, Galileo: Oxford, Oxford University Press, 528 p.<\/li>\n<li class=\"csl-entry\">Hogendijk, J.P., and Sabra, A.I., 2003, The Enterprise of Science in Islam: New Perspectives: MIT Press.<\/li>\n<li class=\"csl-entry\">Jakosky, B.M., Grebowsky, J.M., Luhmann, J.G., Connerney, J., Eparvier, F., Ergun, R., Halekas, J., Larson, D., Mahaffy, P., McFadden, J., Mitchell, D.F., Schneider, N., Zurek, R., Bougher, S., and others, 2015, MAVEN observations of the response of Mars to an interplanetary coronal mass ejection: Science, v. 350, no. 6261, p. aad0210.<\/li>\n<li class=\"csl-entry\">Kerferd, G.B., 1959, The Biography of Aristotle Ingemar D\u00fcring: Aristotle in the Ancient Biographical Tradition. (Studia Graeca et Latina Gothoburgensia v.) Pp. 490; 1 plate. Gothenburg: Institute of Classical Studies, 1957. Paper, Kr. 32: Classical Rev., v. 9, no. 02, p. 128\u2013130.<\/li>\n<li class=\"csl-entry\">Kolbert, E., 2014, The sixth extinction: an unnatural history: New York, Henry Holt and Co., 336 p.<\/li>\n<li class=\"csl-entry\">Krimsky, S., 2013, Do financial conflicts of interest bias research? An inquiry into the \u201cfunding effect\u201d hypothesis: Sci. Technol. Human Values, v. 38, no. 4, p. 566\u2013587.<\/li>\n<li class=\"csl-entry\">Lehmann, I., 1936, P\u2019, Publ: Bur. Centr. Seism. Internat. Serie A, v. 14, p. 87\u2013115.<\/li>\n<li class=\"csl-entry\">Marshall, J., 2010, A short history of Greek philosophy: Andrews UK Limited.<\/li>\n<li class=\"csl-entry\">Martin, C., 2014, Subverting Aristotle: Religion, History, and Philosophy in Early Modern Science: Baltimore\u202f: Johns Hopkins University Press.<\/li>\n<li class=\"csl-entry\">Mayr, E., 1942, Systematics and the Origin of Species, from the Viewpoint of a Zoologist: Harvard University Press.<\/li>\n<li class=\"csl-entry\">Montgomery, K., 2003, Siccar Point and teaching the history of geology: J. Geosci. Educ.<\/li>\n<li class=\"csl-entry\">Mooney, W.D., Laske, G., and Masters, T.G., 1998, CRUST 5.1: A global crustal model: J. Geophys. Res. [Solid Earth], v. 103, no. B1, p. 727\u2013747.<\/li>\n<li class=\"csl-entry\">Moustafa, K., 2016, Aberration of the Citation: Account. Res., v. 23, no. 4, p. 230\u2013244.<\/li>\n<li class=\"csl-entry\">National Center for Science Education, 2016, Climate change denial: Online, <a href=\"http:\/\/ncse.com\/climate\/denial\">http:\/\/ncse.com\/climate\/denial<\/a>, accessed April 2016.<\/li>\n<li class=\"csl-entry\">Oreskes, N., Conway, E., and Cain, S., 2010, Merchants of doubt: how a handful of scientists obscured the truth on issues from tobacco smoke to global warming: Bloomsbury Press, 368 p.<\/li>\n<li class=\"csl-entry\">Paradowski, R.J., 2012, Nicolas Steno: Danish anatomist and geologist: Great Lives from History: Scientists &amp; Science, p. 830\u2013832.<\/li>\n<li class=\"csl-entry\">Patterson, C., 1956, Age of meteorites and the earth: Geochim. Cosmochim. Acta, v. 10, no. 4, p. 230\u2013237.<\/li>\n<li class=\"csl-entry\">Popper, K., 2002, Conjectures and Refutations: The Growth of Scientific Knowledge: London\u202f; New York, Routledge, 608 p.<\/li>\n<li class=\"csl-entry\">Porter, R., 1976, Charles Lyell and the Principles of the History of Geology: Br. J. Hist. Sci., v. 9, no. 02, p. 91\u2013103.<\/li>\n<li class=\"csl-entry\">Railsback, B.L., 1990, T. C. Chamberlin\u2019s \u201cMethod of Multiple Working Hypotheses\u201d: An encapsulation for modern students: Online, <a href=\"http:\/\/www.gly.uga.edu\/railsback\/railsback_chamberlin.html\">http:\/\/www.gly.uga.edu\/railsback\/railsback_chamberlin.html<\/a>, accessed December 2016.<\/li>\n<li class=\"csl-entry\">Railsback, B.L., 2004, T. C. Chamberlin\u2019s \u201cMethod of Multiple Working Hypotheses\u201d: An encapsulation for modern students: Houston Geological Society Bulletin, v. 47, no. 2, p. 68\u201369.<\/li>\n<li class=\"csl-entry\">Rappaport, R., 1994, James Hutton and the History of Geology. Dennis R. Dean: Isis, v. 85, no. 3, p. 524\u2013525.<\/li>\n<li class=\"csl-entry\">Repcheck, J., 2007, Copernicus\u2019 secret: How the scientific revolution began: Simon and Schuster.<\/li>\n<li class=\"csl-entry\">Repcheck, J., 2009, The Man Who Found Time\u202f: James Hutton and the Discovery of the Earth\u2019s Antiquity: New York: Basic Books.<\/li>\n<li class=\"csl-entry\">Sabra, A.I. and Others, 1989, The optics of Ibn al-Haytham: Books I-III: On direct vision: Warburg Institute, University of London.<\/li>\n<li class=\"csl-entry\">Saliba, G., 2007, Islamic science and the making of the European renaissance: MIT Press.<\/li>\n<li class=\"csl-entry\">Shermer, M., 2011, What Is Pseudoscience? Scientific American.<\/li>\n<li class=\"csl-entry\">Snow, C.E. (Ed.), 2016, Science literacy: concepts, contexts, and consequences: Washington, DC, National Academies Press (US).<\/li>\n<li class=\"csl-entry\">Spier, R., 2002, The history of the peer-review process: Trends Biotechnol., v. 20, no. 8, p. 357\u2013358.<\/li>\n<li class=\"csl-entry\">Van Reybrouck, D., 2012, From Primitives to Primates: A History of Ethnographic and Primatological Analogies in the Study of Prehistory: Sidestone Press.<\/li>\n<li class=\"csl-entry\">Waters, C.N., Zalasiewicz, J., Summerhayes, C., Barnosky, A.D., Poirier, C., Ga\\luszka, A., Cearreta, A., Edgeworth, M., Ellis, E.C., Ellis, M., Jeandel, C., Leinfelder, R., McNeill, J.R., Richter, D.D., and others, 2016, The Anthropocene is functionally and stratigraphically distinct from the Holocene: Science, v. 351, no. 6269, p. aad2622.<\/li>\n<li class=\"csl-entry\">de Wijs, G.A., Kresse, G., Vo\u010dadlo, L., Dobson, D., Alf\u00e8, D., Gillan, M.J., and Price, G.D., 1998, The viscosity of liquid iron at the physical conditions of the Earth\u2019s core: Nature, v. 392, no. 6678, p. 805\u2013807., doi: <a href=\"https:\/\/doi.org\/10.1038\/33905\">10.1038\/33905<\/a>.<\/li>\n<li class=\"csl-entry\">Wyhe, J.V., 2008, Darwin: Andre Deutsch, 72 p.<\/li>\n<li class=\"csl-entry\">Wyllie, P.J., 1970, Ultramafic rocks and the upper mantle, <i>in<\/i> Morgan, B.A., editor, Fiftieth anniversary symposia: Mineralogy and petrology of the Upper Mantle; Sulfides; Mineralogy and geochemistry of non-marine evaporites: Washington, DC, Mineralogical Society of America, p. 3\u201332.<\/li>\n<li class=\"csl-entry\">Zalasiewicz, J., Williams, M., Smith, A., Barry, T.L., Coe, A.L., Bown, P.R., Brenchley, P., Cantrill, D., Gale, A., Gibbard, P., and Others, 2008, Are we now living in the Anthropocene? GSA Today, v. 18, no. 2, p. 4.<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1016\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1016\"><div tabindex=\"-1\"><p>Faulting that is deep into the crust, and typically involves crystalline basement rocks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2007\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2007\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1791\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1791\"><div tabindex=\"-1\"><figure id=\"attachment_2498\" aria-describedby=\"caption-attachment-2498\" style=\"width: 2048px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/MT3.jpg\"><img class=\"wp-image-67 size-full\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2021\/09\/MT3.jpg\" alt=\"The rock is getting thinner farther away.\" width=\"2048\" height=\"1536\"><\/a><figcaption id=\"caption-attachment-2498\" class=\"wp-caption-text\">A layer of shallow ocean limestone (white) has been brought to the top of a mountain by the convergent forces of the Sevier Orogeny. Near Sun River Canyon, Montana.<\/figcaption><\/figure>\n<h1>2 Plate Tectonics<\/h1>\n<p><b>KEY CONCEPTS<\/b><\/p>\n<p><b>At the end of this chapter, students should be able to:<\/b><\/p>\n<ul>\n<li>Describe how the ideas behind <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> started with Alfred Wegener\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a>\u00a0drift<\/li>\n<li>Describe the physical and chemical layers of the Earth and how they affect <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement<\/li>\n<li>Explain how movement at the three types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> boundaries causes earthquakes, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanoes<\/a>, and mountain building<\/li>\n<li>Identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1678\">convergent<\/a> boundaries, including <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> and collisions, as places where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>\u00a0come together<\/li>\n<li>Identify <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundaries, including <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifts<\/a>\u00a0and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a>, as places where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> separate<\/li>\n<li>Explain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> boundaries as places where adjacent <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_494\">shear<\/a> past each other<\/li>\n<li>Describe the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1715\">Wilson Cycle<\/a>, beginning with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a>, ocean <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> creation, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a>, and ending with ocean <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> closure<\/li>\n<li>Explain how the tracks of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a>, places that have continually rising <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>, is used to calculate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> motion<\/li>\n<\/ul>\n<figure id=\"attachment_2499\" aria-describedby=\"caption-attachment-2499\" style=\"width: 4898px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Tectonic_plates_boundaries_detailed-en.svg_.png\"><img class=\"size-full wp-image-68\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tectonic_plates_boundaries_detailed-en.svg_.png\" alt=\"The map shows many plates.\" width=\"4898\" height=\"2461\"><\/a><figcaption id=\"caption-attachment-2499\" class=\"wp-caption-text\">Detailed map of all known plates, their boundaries, and movements.<\/figcaption><\/figure>\n<p>Revolution is a word usually reserved for significant political or social changes. Several of these idea revolutions forced scientists to re-examine their entire field, triggering a paradigm shift that shook up their conventionally held knowledge. Charles Darwin\u2019s book on evolution, <em>On the Origin of Species<\/em>, published in 1859; Gregor Mendel\u2019s discovery of the genetic principles of inheritance in 1866; and James Watson, Francis Crick, and Rosalind Franklin\u2019s model for the structure of DNA in 1953 did that for biology. Albert Einstein\u2019s relativity and quantum mechanics concepts in the early twentieth century did the same for Newtonian physics.<\/p>\n<p>The concept of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> was just as revolutionary for geology. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> attributes the movement of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_985\">massive<\/a> sections of the Earth\u2019s outer layers with creating earthquakes, mountains, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanoes<\/a>. Many earth processes make more sense when viewed through the lens of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a>. Because it is so important in understanding how the world works, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> is the first topic of discussion in this textbook.<\/p>\n<h2><span style=\"font-weight: 400;\">2.1 Alfred Wegener\u2019s Continental Drift Hypothesis<\/span><\/h2>\n<figure id=\"attachment_2500\" aria-describedby=\"caption-attachment-2500\" style=\"width: 195px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Alfred_Wegener_ca.1924-30-2.jpg\"><img class=\"size-full wp-image-28\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Alfred_Wegener_ca.1924-30-2.jpg\" alt=\"He is a male in a suit.\" width=\"195\" height=\"240\"><\/a><figcaption id=\"caption-attachment-2500\" class=\"wp-caption-text\">Wegener later in his life, ca. 1924-1930.<\/figcaption><\/figure>\n<p>Alfred Wegener (1880-1930) was a German scientist who specialized in meteorology and climatology. His knack for questioning accepted ideas started in 1910 when he disagreed with the explanation that the Bering Land Bridge was formed by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_753\">isostasy<\/a>, and that similar land bridges once connected the continents. After reviewing the scientific literature, he published a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> stating the continents were originally connected, and then drifted apart. While he did not have the precise mechanism worked out, his <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> was backed up by a long list of evidence.<\/p>\n<h3><\/h3>\n<h3><b>2.1.1 Early Evidence for Continental Drift Hypothesis<\/b><\/h3>\n<figure id=\"attachment_2501\" aria-describedby=\"caption-attachment-2501\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Antonio_Snider-Pellegrini_Opening_of_the_Atlantic.jpg\"><img class=\"size-medium wp-image-69\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Antonio_Snider-Pellegrini_Opening_of_the_Atlantic-300x177.jpg\" alt=\"It shows South America and Africa connected, then apart.\" width=\"300\" height=\"177\"><\/a><figcaption id=\"caption-attachment-2501\" class=\"wp-caption-text\">Snider-Pellegrini's map showing the continental fit and separation, 1858.<\/figcaption><\/figure>\n<p>Wegener\u2019s first piece of evidence was that the coastlines of some continents fit together like pieces of a jigsaw puzzle. People noticed the similarities in the coastlines of South America and Africa on the first world maps, and some suggested the continents had been ripped apart. Antonio Snider-Pellegrini did preliminary work on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> separation and matching <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a> in 1858.<\/p>\n<figure id=\"attachment_2502\" aria-describedby=\"caption-attachment-2502\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/ElevationWorld.jpg\"><img class=\"size-medium wp-image-70\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/ElevationWorld-300x150.jpg\" alt=\"The shape of the continents is different than what is seen by just coastlines.\" width=\"300\" height=\"150\"><\/a><figcaption id=\"caption-attachment-2502\" class=\"wp-caption-text\">Map of world elevations. Note the light blue, which are continental shelves flooded by shallow ocean water. These show the true shapes of the continents.<\/figcaption><\/figure>\n<p>What Wegener did differently was synthesize a large amount of data in one place. He used true edges of the continents, based on the shapes of the continental shelves. This resulted in a better fit than previous efforts that traced the existing coastlines.<\/p>\n<figure id=\"attachment_3259\" aria-describedby=\"caption-attachment-3259\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Wegener_fossil_map.svg_.png\"><img class=\"size-medium wp-image-71\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Wegener_fossil_map.svg_-300x231.png\" alt=\"There are four different fossil organisms that connect South America, Africa, India, Antartica, and Australia.\" width=\"300\" height=\"231\"><\/a><figcaption id=\"caption-attachment-3259\" class=\"wp-caption-text\">Image showing fossils that connect the continents of Gondwana (the southern continents of Pangea).<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Wegener also compiled evidence by comparing similar rocks, mountains, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a>, and glacial formations across oceans. For example, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a> of the primitive aquatic reptile <em>Mesosaurus<\/em> were found on the separate coastlines of Africa and South America. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">Fossils<\/a> of another reptile, <em>Lystrosaurus,<\/em> were found on Africa, India, and Antarctica. He pointed out these were land-dwelling creatures could not have swum across an entire ocean.<\/p>\n<p>Opponents of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> drift insisted trans-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic <\/a> land bridges allowed animals and plants to move between continents. The land bridges eventually eroded away, leaving the continents permanently separated. The problem with this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> is the improbability of a land bridge being tall and long enough to stretch across a broad, deep ocean.<\/p>\n<p>More support for <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> drift came from the puzzling evidence that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1516\">glaciers<\/a> once existed in normally very warm areas in southern Africa, India, Australia, and Arabia. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_765\">anomalies<\/a> could not be explained by land bridges. Wegener found similar evidence when he discovered tropical plant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossils<\/a> in the frozen region of the Arctic Circle. As Wegener collected more data, he realized the explanation that best fit all the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a>, rock, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossil<\/a> observations involved moving continents.<\/p>\n<h3><b>2.1.2 Proposed Mechanism for Continental Drift<\/b><\/h3>\n<figure id=\"attachment_2504\" aria-describedby=\"caption-attachment-2504\" style=\"width: 400px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Convection.gif\"><img class=\"wp-image-72 size-full\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Convection.gif\" alt=\"The rising material is drawn red. The cool material is blue.\" width=\"400\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2504\" class=\"wp-caption-text\">Animation of the basic idea of convection: an uneven heat source in a fluid causes rising material next to the heat and sinking material far from the heat.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Wegener\u2019s work was considered a fringe science <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> for his entire life. One of the biggest flaws in his <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> was an inability to provide a mechanism for how the continents moved. Obviously, the continents did not appear to move, and changing the conservative minds of the scientific community would require exceptional evidence that supported a credible mechanism. Other pro-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> drift followers used expansion, contraction, or even the moon\u2019s origin to explain how the continents moved. Wegener used centrifugal forces and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_749\">precession<\/a>, but this model was proven wrong. He also speculated about seafloor spreading, with hints of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1655\">convection<\/a>, but could not substantiate these proposals. As it turns out, current scientific knowledge reveals <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1655\">convection<\/a> is one the major forces in driving <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movements, along with gravity and density.<\/p>\n<h3><b>2.1.3 Development of Plate Tectonic Theory<\/b><\/h3>\n<figure id=\"attachment_2505\" aria-describedby=\"caption-attachment-2505\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Global_plate_motion_2008-04-17.jpg\"><img class=\"size-medium wp-image-73\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Global_plate_motion_2008-04-17-300x212.jpg\" alt=\"The map shows many data points all over the world.\" width=\"300\" height=\"212\"><\/a><figcaption id=\"caption-attachment-2505\" class=\"wp-caption-text\">GPS measurements of plate motions.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Wegener died in 1930 on an expedition in Greenland. Poorly respected in his lifetime, Wegener and his ideas about moving continents seemed destined to be lost in history as fringe science. However, in the 1950s, evidence started to trickle in that made <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> drift a more viable idea. By the 1960s, scientists had amassed enough evidence to support the missing mechanism\u2014namely, seafloor spreading\u2014for Wegener\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> drift to be accepted as the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a>. Ongoing GPS and earthquake data analyses continue to support this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a>. The next section provides the pieces of evidence that helped <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> one man\u2019s wild notion into a scientific <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a>.<\/p>\n<h4><span style=\"font-weight: 400;\">Mapping of the Ocean Floors<\/span><\/h4>\n<figure id=\"attachment_2506\" aria-describedby=\"caption-attachment-2506\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Deep_sea_vent_chemistry_diagram.jpg\"><img class=\"size-medium wp-image-74\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Deep_sea_vent_chemistry_diagram-300x174.jpg\" alt=\"The diagram shows water going into the ground and coming out, with many different reactions.\" width=\"300\" height=\"174\"><\/a><figcaption id=\"caption-attachment-2506\" class=\"wp-caption-text\">The complex chemistry around mid-ocean ridges.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>In 1947 researchers started using an adaptation of SONAR to map a region in the middle of the Atlantic Ocean with poorly-understood topographic and thermal properties. Using this information, Bruce Heezen and Marie Tharp created the first detailed map of the ocean floor to reveal the Mid-Atlantic Ridge, a basaltic mountain range that spanned the length of the Atlantic Ocean, with rock chemistry and dimensions unlike the mountains found on the continents. Initially scientists thought the ridge was part of a mechanism that explained the expanding Earth or ocean-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> growth <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypotheses<\/a>. In 1959, Harry Hess proposed the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> of seafloor spreading \u2013 that the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> represented <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> factories, where new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> was issuing from these long <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> ridges. Scientists later included <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> faults perpendicular to the ridges to better account for varying rates of movement between the newly formed <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. When earthquake epicenters were discovered along the ridges, the idea that earthquakes were linked to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement took hold.<\/p>\n<div style=\"height: 0; padding-bottom: 56.25%;\">\n<\/div>\n<figure id=\"attachment_3739\" aria-describedby=\"caption-attachment-3739\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Marie-Tharp-YouTube-QR-Code.png\"><img class=\"size-thumbnail wp-image-75\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Marie-Tharp-YouTube-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3739\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this YouTube video via this QR Code.<\/figcaption><\/figure>\n<p>Seafloor <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediment<\/a>, measured by dredging and drilling, provided another clue. Scientists once believed <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediment<\/a> accumulated on the ocean floors over a very long time in a static environment. When some studies showed less <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediment<\/a> than expected, these results were initially used to argue against <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> movement. With more time, researchers discovered these thinner <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediment<\/a> layers were located close to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a>, indicating the ridges were younger than the surrounding ocean floor. This finding supported the idea that the sea floor was not fixed in one place.<\/p>\n<h4><span style=\"font-weight: 400;\">Paleomagnetism<\/span><\/h4>\n<figure id=\"attachment_2507\" aria-describedby=\"caption-attachment-2507\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Earths_magnetic_field_schematic.svg_.png\"><img class=\"size-medium wp-image-76\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Earths_magnetic_field_schematic.svg_-300x250.png\" alt=\"The north end of the magnet is south topographically, and vice versa.\" width=\"300\" height=\"250\"><\/a><figcaption id=\"caption-attachment-2507\" class=\"wp-caption-text\">The magnetic field of Earth, simplified as a bar magnet.<\/figcaption><\/figure>\n<p>The seafloor was also mapped magnetically. Scientists had long known of strange magnetic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_765\">anomalies<\/a> that formed a striped pattern of symmetrical rows on both sides of mid-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> ridges. What made these features unusual was the north and south magnetic poles within each stripe was reversed in alternating rows. By 1963, Harry Hess and other scientists used these magnetic reversal patterns to support their model for seafloor spreading (see also Lawrence W. Morley).<\/p>\n<figure id=\"attachment_2508\" aria-describedby=\"caption-attachment-2508\" style=\"width: 351px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Earth_Magnetic_Field_Declination_from_1590_to_1990.gif\"><img class=\"wp-image-77 size-full\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Earth_Magnetic_Field_Declination_from_1590_to_1990.gif\" alt=\"The poles shift slightly every year.\" width=\"351\" height=\"293\"><\/a><figcaption id=\"caption-attachment-2508\" class=\"wp-caption-text\">This animation shows how the magnetic poles have moved over 400 years.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1657\">Paleomagnetism<\/a> is the study of magnetic fields frozen within rocks, basically a fossilized compass. In fact, the first hard evidence to support <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> motion came from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1657\">paleomagnetism<\/a>.<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">Igneous<\/a> rocks containing magnetic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> like magnetite typically provide the most useful data. In their liquid state as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a>, the magnetic poles of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> align themselves with the Earth\u2019s magnetic field. When the rock cools and solidifies, this alignment is frozen into place, creating a permanent paleomagnetic record that includes magnetic inclination related to global latitude, and declination related to magnetic north.<\/p>\n<figure id=\"attachment_2509\" aria-describedby=\"caption-attachment-2509\" style=\"width: 240px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/02.1-magnetic_stripes.gif\"><img class=\"size-full wp-image-78\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/02.1-magnetic_stripes.gif\" alt=\"Animated gif depicting a mid-ocean ridge with two oceanic plates moving away from the center of the ridge. As the movement progresses, symettrical magnetic stripes appear on each side of the ridge.\" width=\"240\" height=\"180\"><\/a><figcaption id=\"caption-attachment-2509\" class=\"wp-caption-text\">The iron in the solidifying rock preserves the current magnetic polarity as new oceanic plates form at mid ocean ridges<\/figcaption><\/figure>\n<p>Scientists had noticed for some time the alignment of magnetic north in many rocks was nowhere close to the earth\u2019s current magnetic north. Some explained this away are part of the normal movement of earth\u2019s magnetic north pole. Eventually, scientists realized adding the idea of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> movement explained the data better than pole movement alone.<\/p>\n<h4><\/h4>\n<h4><\/h4>\n<h4><span style=\"font-weight: 400;\">Wadati-Benioff Zones<\/span><\/h4>\n<figure id=\"attachment_2510\" aria-describedby=\"caption-attachment-2510\" style=\"width: 297px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/benioff_zone.gif\"><img class=\"size-full wp-image-79\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/benioff_zone.gif\" alt=\"The earthquakes descend at an angle into the Earth.\" width=\"297\" height=\"243\"><\/a><figcaption id=\"caption-attachment-2510\" class=\"wp-caption-text\">The Wadati-Benioff zone, showing earthquakes following the subducting slab down.<\/figcaption><\/figure>\n<p>Around the same time <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> were being investigated, other scientists linked the creation of ocean trenches and island arcs to seismic activity and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement. Several independent research groups recognized earthquake epicenters traced the shapes of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> sinking into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>. These deep earthquake zones congregated in planes that started near the surface around ocean trenches and angled beneath the continents and island arcs. Today these earthquake zones called Wadati-Benioff zones.<\/p>\n<figure id=\"attachment_2511\" aria-describedby=\"caption-attachment-2511\" style=\"width: 244px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/John_Tuzo_Wilson_in_1992-2.jpg\"><img class=\"size-medium wp-image-39\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/John_Tuzo_Wilson_in_1992-2-244x300.jpg\" alt=\"He is an older man in this 1992 image.\" width=\"244\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2511\" class=\"wp-caption-text\">J. Tuzo Wilson<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Based on the mounting evidence, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> continued to take shape. J. Tuzo Wilson was the first scientist to put the entire picture together by proposing that the opening and closing of the ocean basins. Before long, scientists proposed other models showing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> moving with respect to each other, with clear boundaries between them. Others started piecing together complicated histories of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> revolution had taken hold.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div id=\"h5p-8\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-8\" class=\"h5p-iframe\" data-content-id=\"8\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Continental Drift vs. Plate Tectonics\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3738\" aria-describedby=\"caption-attachment-3738\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Continental-Drive-Activity-QR-Code.png\"><img class=\"size-thumbnail wp-image-80\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Continental-Drive-Activity-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3738\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this interactive activity via this QR Code.<\/figcaption><\/figure>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-9\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-9\" class=\"h5p-iframe\" data-content-id=\"9\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2.1 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3737\" aria-describedby=\"caption-attachment-3737\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/2.1-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-81\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/2.1-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3737\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 2.1 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400;\">2.2 Layers of the Earth<\/span><\/h2>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2512\" aria-describedby=\"caption-attachment-2512\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Earth-cutaway-schematic-english.svg_-1.png\"><img class=\"size-medium wp-image-51\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Earth-cutaway-schematic-english.svg_-1-300x211.png\" alt=\"The crust and lithosphere are on the outside of the Earth and are thin. Below the crust is the mantle and core. Below the lithosphere is the asthenosphere.\" width=\"300\" height=\"211\"><\/a><figcaption id=\"caption-attachment-2512\" class=\"wp-caption-text\">The layers of the Earth. Physical layers include lithosphere and asthenosphere; chemical layers are crust, mantle, and core.<\/figcaption><\/figure>\n<p>In order to understand the details of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a>, it is essential to first understand the layers of the earth. Firsthand information about what is below the surface is very limited; most of what we know is pieced together from hypothetical models, and analyzing seismic wave data and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1254\">meteorite<\/a> materials. In general, the Earth can be divided into layers based on chemical composition and physical characteristics.<\/p>\n<h3><b>2.2.1 Chemical Layers<\/b><\/h3>\n<p>Certainly the earth is composed of a countless combination of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. Regardless of what <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> are involved two major factors\u2014<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> and pressure\u2014are responsible for creating three distinct chemical layers.<\/p>\n<h4><span style=\"font-weight: 400;\">Crust<\/span><\/h4>\n<p>The outermost chemical layer and the one we currently reside on, is the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>. There are two types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">Continental crust<\/a> has a relatively low density and composition similar to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1014\">granite<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">Oceanic crust<\/a> has a relatively high density, especially when cold and old, and composition similar to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1013\">basalt<\/a>. The surface levels of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> are relatively <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1661\">brittle<\/a>. The deeper parts of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> are subjected to higher temperatures and pressure, which makes them more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1660\">ductile<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1660\">Ductile<\/a> materials are like soft plastics or putty, they move under force. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1661\">Brittle<\/a> materials are like solid glass or pottery, they break under force, especially when it is applied quickly. Earthquakes, generally occur in the upper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> and are caused by the rapid movement of relatively <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1661\">brittle<\/a> materials.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2513\" aria-describedby=\"caption-attachment-2513\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/MohoDepth-1.png\"><img class=\"size-medium wp-image-50\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MohoDepth-1-300x167.png\" alt=\"Places with mountain building have a deeper moho.\" width=\"300\" height=\"167\"><\/a><figcaption id=\"caption-attachment-2513\" class=\"wp-caption-text\">The global map of the depth of the moho.<\/figcaption><\/figure>\n<p>The base of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> is characterized by a large increase in seismic velocity, which measures how fast earthquake waves travel through solid matter. Called the Mohorovi\u010di\u0107 Discontinuity, or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1662\">Moho<\/a> for short, this zone was discovered by Andrija Mohorovi\u010di\u0107 (pronounced mo-ho-ro-vee-cheech; <a href=\"https:\/\/www.merriam-webster.com\/dictionary\/Mohorovicic%20discontinuity\">audio pronunciation<\/a>) in 1909 after studying earthquake wave paths in his <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a> Croatia. The change in wave direction and speed is caused by dramatic chemical differences of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>. Underneath the oceans, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1662\">Moho<\/a> is found roughly 5 km below the ocean floor. Under the continents, it is located about 30-40 km below the surface. Near certain large mountain-building events known as orogenies, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1662\">Moho<\/a> depth is doubled.<\/p>\n<h4><span style=\"font-weight: 400;\">Mantle<\/span><\/h4>\n<figure id=\"attachment_2514\" aria-describedby=\"caption-attachment-2514\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Iddingsite.jpg\"><img class=\"size-medium wp-image-82\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Iddingsite-300x225.jpg\" alt=\"The xenolith sits on top of a basalt rock. It has three sides like a pyramid; one of the sides is more altered to iddingsite.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-2514\" class=\"wp-caption-text\">This mantle xenolith containing olivine (green) is chemically weathering by hydrolysis and oxidation into the pseudo-mineral iddingsite, which is a complex of water, clay, and iron oxides. The more altered side of the rock has been exposed to the environment longer.<\/figcaption><\/figure>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> sits below the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> and above the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a>. It is the largest chemical layer by volume, extending from the base of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> to a depth of about 2900 km. Most of what we know about the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> comes from seismic wave analysis, though information is gathered by studying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1700\">ophiolites<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1665\">xenoliths<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1700\">Ophiolites<\/a> are pieces of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> that have risen through the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> until they are exposed as part of the ocean floor. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1665\">Xenoliths<\/a> are carried within <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> and brought to the Earth\u2019s surface by volcanic eruptions. Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1665\">xenoliths<\/a> are made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1666\">peridotite<\/a>, an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">ultramafic<\/a> class of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous rock<\/a> (see <a href=\"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/4-igneous-processes-and-volcanoes#4-2BowensReaction\" target=\"_blank\" rel=\"noopener\">chapter 4.2<\/a> for explanation). Because of this, scientists hypothesize most of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> is made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1666\">peridotite<\/a>.<\/p>\n<h4><span style=\"font-weight: 400;\">Core<\/span><\/h4>\n<figure id=\"attachment_2515\" aria-describedby=\"caption-attachment-2515\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/02.2_TolucaMeteorite.jpg\"><img class=\"size-medium wp-image-83\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/02.2_TolucaMeteorite-300x225.jpg\" alt=\"The meteorite is polished showing the Widmanst\u00e4tten Pattern.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-2515\" class=\"wp-caption-text\">A polished fragment of the iron-rich Toluca Meteorite, with octahedral Widmanst\u00e4tten Pattern.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a> of the Earth, which has both liquid and solid layers, and consists mostly of iron, nickel, and possibly some oxygen. Scientists looking at seismic data first discovered this innermost chemical layer in 1906. Through a union of hypothetical modeling, astronomical insight, and hard seismic data, they concluded the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a> is mostly metallic iron. Scientists studying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1254\">meteorites<\/a>, which typically contain more iron than surface rocks, have proposed the earth was formed from meteoric material. They believe the liquid component of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a> was created as the iron and nickel sank into the center of the planet, where it was liquefied by intense pressure.<\/p>\n<h3><b>2.2.2 Physical Layers<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">The Earth can also be broken down into five distinct physical layers based on how each layer responds to stress. While there is some overlap in the chemical and physical designations of layers, specifically the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a>-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> boundary, there are significant differences between the two systems.<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">Lithosphere<\/span><\/h4>\n<figure id=\"attachment_2516\" aria-describedby=\"caption-attachment-2516\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Plates_tect2_en.svg_-2.png\"><img class=\"size-medium wp-image-49\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Plates_tect2_en.svg_-2-300x205.png\" alt=\"There are about 10 major plates\" width=\"300\" height=\"205\"><\/a><figcaption id=\"caption-attachment-2516\" class=\"wp-caption-text\">Map of the major plates and their motions along boundaries.<\/figcaption><\/figure>\n<p><em>Lithos<\/em> is Greek for stone, and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> is the outermost physical layer of the Earth. It is grouped into two types: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">Oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> is thin and relatively rigid. It ranges in thickness from nearly zero in new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> found around <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a>, to an average of 140 km in most other locations. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">Continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> is generally thicker and considerably more plastic, especially at the deeper levels. Its thickness ranges from 40 to 280 km. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> is not continuous. It is broken into segments called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1670\">plate boundary<\/a> is where two <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> meet and move relative to each other. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">Plate<\/a> boundaries are where we see <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> in action\u2014mountain building, triggering earthquakes, and generating <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> activity.<\/p>\n<h4><span style=\"font-weight: 400;\">Asthenosphere<\/span><\/h4>\n<figure id=\"attachment_2517\" aria-describedby=\"caption-attachment-2517\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Earths_Inner_Layers_denoting_the_LAB.png\"><img class=\"size-medium wp-image-84\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Earths_Inner_Layers_denoting_the_LAB-300x207.png\" alt=\"It is thin at a mid-ocean ridge, thick under collisions\" width=\"300\" height=\"207\"><\/a><figcaption id=\"caption-attachment-2517\" class=\"wp-caption-text\">The lithosphere-asthenosphere boundary changes with certain tectonic situations.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a> is the layer below the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>. <em>Astheno-<\/em> means lacking strength, and the most distinctive property of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a> is movement. Because it is mechanically weak, this layer moves and flows due to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1655\">convection<\/a> currents created by heat coming from the earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a> cause. Unlike the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> that consists of multiple <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a> is relatively unbroken. Scientists have determined this by analyzing seismic waves that pass through the layer. The depth of at which the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a> is found is <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a>-dependent. It tends to lie closer to the earth\u2019s surface around <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> and much deeper underneath mountains and the centers of lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>.<\/p>\n<h4><span style=\"font-weight: 400;\">Mesosphere<\/span><\/h4>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2518\" aria-describedby=\"caption-attachment-2518\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Perovskite.jpg\"><img class=\"size-medium wp-image-85\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Perovskite-300x288.jpg\" alt=\"The atoms are arranged.\" width=\"300\" height=\"288\"><\/a><figcaption id=\"caption-attachment-2518\" class=\"wp-caption-text\">General perovskite structure. Perovskite silicates (i.e.<br \/>Bridgmenite,<br \/>(Mg,Fe)SiO3) are thought to be the main component of the lower mantle, making it the most common mineral in or on Earth.<\/figcaption><\/figure>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1672\">mesosphere<\/a>, sometimes known as the lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>, is more rigid and immobile than the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a>. Located at a depth of approximately 410 and 660 km below the earth\u2019s surface, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1672\">mesosphere<\/a> is subjected to very high pressures and temperatures. These extreme conditions create a transition zone in the upper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1672\">mesosphere<\/a> where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> continuously change into various forms, or pseudomorphs. Scientists identify this zone by changes in seismic velocity and sometimes physical barriers to movement. Below this transitional zone, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1672\">mesosphere<\/a> is relatively uniform until it reaches the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a>.<\/p>\n<h4><span style=\"font-weight: 400;\">Inner and Outer Core<\/span><\/h4>\n<figure id=\"attachment_2519\" aria-describedby=\"caption-attachment-2519\" style=\"width: 206px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Inge_Lehmann_1932.jpg\"><img class=\"size-medium wp-image-86\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Inge_Lehmann_1932-206x300.jpg\" alt=\"Is shows her as a young woman\" width=\"206\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2519\" class=\"wp-caption-text\">Lehmann in 1932<\/figcaption><\/figure>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1673\">outer core<\/a> is the only entirely liquid layer within the Earth. It starts at a depth of 2,890 km and extends to 5,150 km, making it about 2,300 km thick. In 1936, the Danish geophysicist Inge Lehmann analyzed seismic data and was the first to prove a solid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1674\">inner core<\/a> existed within a liquid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1673\">outer core<\/a> . The solid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1674\">inner core<\/a> is about 1,220 km thick, and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1673\">outer core<\/a> is about 2,300 km thick.<\/p>\n<p>It seems like a contradiction that the hottest part of the Earth is solid, as the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> making up the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a> should be liquified or vaporized at this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a>. Immense pressure keeps the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1674\">inner core<\/a> in a solid phase. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1674\">inner core<\/a> grows slowly from the lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1673\">outer core<\/a> solidifying as heat escapes the interior of the Earth and is dispersed to the outer layers.<\/p>\n<figure id=\"attachment_2520\" aria-describedby=\"caption-attachment-2520\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/02.2_SpinningOuterCore.gif\"><img class=\"size-medium wp-image-87\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/02.2_SpinningOuterCore-300x289.gif\" alt=\"The Earth is cut out with the core being shown.\" width=\"300\" height=\"289\"><\/a><figcaption id=\"caption-attachment-2520\" class=\"wp-caption-text\">The outer core's spin causes our protective magnetic field.<\/figcaption><\/figure>\n<p>The earth\u2019s liquid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1673\">outer core<\/a> is critically important in maintaining a breathable <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a> and other environmental conditions favorable for life. Scientists believe the earth\u2019s magnetic field is generated by the circulation of molten iron and nickel within the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1673\">outer core<\/a>. If the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1673\">outer core<\/a> were to stop circulating or become solid, the loss of the magnetic field would result in Earth getting stripped of life-supporting gases and water. This is what happened, and continues to happen, on Mars.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div id=\"h5p-10\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-10\" class=\"h5p-iframe\" data-content-id=\"10\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Layers of the Earth practice\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3736\" aria-describedby=\"caption-attachment-3736\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Layers-of-Earth-Practice-QR-Code.png\"><img class=\"size-thumbnail wp-image-88\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Layers-of-Earth-Practice-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3736\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this interactive activity via this QR Code.<\/figcaption><\/figure>\n<h3><b>2.2.3 Plate Tectonic Boundaries<\/b><\/h3>\n<figure id=\"attachment_2521\" aria-describedby=\"caption-attachment-2521\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Passive_Contiental_Margin.jpg\"><img class=\"size-medium wp-image-89\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Passive_Contiental_Margin-300x143.jpg\" alt=\"The plate thins from continent to ocean\" width=\"300\" height=\"143\"><\/a><figcaption id=\"caption-attachment-2521\" class=\"wp-caption-text\">Passive margin<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>At passive margins the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> don\u2019t move\u2014the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> transitions into oceanic lithosphere and forms <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> made of both types. A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> may be made of both <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> connected by a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1676\">passive margin<\/a>. North and South America\u2019s eastern coastlines are examples of passive margins. Active margins are places where the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> meet and move relative to each other, such as the western coasts of North and South America. This movement is caused by frictional drag created between the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> and differences in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> densities. The majority of mountain-building events, earthquake activity and active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> on the Earth\u2019s surface can be attributed to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement at active margins.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2522\" aria-describedby=\"caption-attachment-2522\" style=\"width: 775px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Tectonic_plate_boundaries.png\"><img class=\"size-full wp-image-90\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tectonic_plate_boundaries.png\" alt=\"It shows all the types\" width=\"775\" height=\"429\"><\/a><figcaption id=\"caption-attachment-2522\" class=\"wp-caption-text\">Schematic of plate boundary types.<\/figcaption><\/figure>\n<p>In a simplified model, there are three categories of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> boundaries. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1678\">Convergent<\/a> boundaries are places where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> move toward each other. At <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundaries, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> move apart. At <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> boundaries, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> slide past each other.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-11\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-11\" class=\"h5p-iframe\" data-content-id=\"11\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2.2 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3735\" aria-describedby=\"caption-attachment-3735\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/2.2-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-91\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/2.2-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3735\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 2.2 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-size: 28px;\">2.3 Convergent Boundaries<\/span><\/h2>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2523\" aria-describedby=\"caption-attachment-2523\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/CratonGeolProv.jpg\"><img class=\"size-medium wp-image-92\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/CratonGeolProv-300x159.jpg\" alt=\"The legend shows shields, platforms, orogens, basins, large igneous provinces, and extended crust.\" width=\"300\" height=\"159\"><\/a><figcaption id=\"caption-attachment-2523\" class=\"wp-caption-text\">Geologic provinces with the Shield (orange) and Platform (pink) comprising the Craton, the stable interior of continents.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1678\">Convergent<\/a> boundaries, also called destructive boundaries, are places where two or more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> move toward each other. . <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1678\">Convergent<\/a> boundary movement is divided into two types, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a>, depending on the density of the involved <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">Continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> is of lower density and thus more buoyant than the underlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">Oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> is more dense than <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>, and, when old and cold, may even be more dense than <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a>.<\/p>\n<p>When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> of different densities converge, the higher density <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> is pushed beneath the more buoyant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> in a process called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a>. When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> converge without <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> occurring, this process is called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a>.<\/p>\n<h3><b>2.3.1. Subduction<\/b><\/h3>\n<div style=\"width: 720px;\" class=\"wp-video\"><video class=\"wp-video-shortcode\" id=\"video-233-1\" width=\"720\" height=\"540\" preload=\"metadata\" controls=\"controls\"><source type=\"video\/mp4\" src=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/Subduction.mp4?_=1\" \/><a href=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/Subduction.mp4\">http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/Subduction.mp4<\/a><\/video><\/div>\n<p><em><a href=\"http:\/\/emvc.geol.ucsb.edu\/2_infopgs\/IP1GTect\/cSubduction.html\">Video<\/a> showing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\"><em>continental<\/em><\/a>-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\"><em>oceanic <\/em><\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\"><em>subduction<\/em><\/a>, causing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\"><em>volcanism<\/em><\/a>. By Tanya Atwater and John Iwerks.<\/em><\/p>\n<figure id=\"attachment_3734\" aria-describedby=\"caption-attachment-3734\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Subduction-Animation-QR-Code.png\"><img class=\"size-thumbnail wp-image-93\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Subduction-Animation-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3734\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this video via this QR Code.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">Subduction<\/a> occurs when a dense <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> meets a more buoyant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>, like a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> or warmer\/younger <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>, and descends into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>. The worldwide average rate of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> is 25 miles per million years, about a half-inch per year. As an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> descends, it pulls the ocean floor down into a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1681\">trench<\/a>. These trenches can be more than twice as deep as the average depth of the adjacent ocean <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a>, which is usually three to four km. The Mariana <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1681\">Trench<\/a>, for example, approaches a staggering 11 km.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2524\" aria-describedby=\"caption-attachment-2524\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Subduction-en.svg_.png\"><img class=\"size-full wp-image-94\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Subduction-en.svg_.png\" alt=\"Many features are labeled on the diagram, but the main idea is the ocean plate descending below the continental\" width=\"800\" height=\"391\"><\/a><figcaption id=\"caption-attachment-2524\" class=\"wp-caption-text\">Diagram of ocean-continent subduction.<\/figcaption><\/figure>\n<figure id=\"attachment_2525\" aria-describedby=\"caption-attachment-2525\" style=\"width: 212px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/drawing.png\"><img class=\"size-medium wp-image-95\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/drawing-212x300.png\" alt=\"This drawing depicts a microcontinent riding with a subducting plate, and not being subductable, becoming accreted to the melange.\" width=\"212\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2525\" class=\"wp-caption-text\">Microcontinents can become part of the accretionary prism of a subduction zone.<\/figcaption><\/figure>\n<p>Within the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1681\">trench<\/a>, ocean floor <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> are scraped together and compressed between the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducting<\/a> and overriding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. This feature is called the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1682\">accretionary wedge<\/a>, m\u00e9lange, or accretionary prism. Fragments of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> material, including microcontinents, riding atop the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducting<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> may become sutured to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1682\">accretionary wedge <\/a> and accumulate into a large area of land called a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1764\">terrane<\/a>. Vast portions of California are comprised of accreted terranes.<\/p>\n<figure id=\"attachment_2526\" aria-describedby=\"caption-attachment-2526\" style=\"width: 179px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/usgs_terranes.gif\"><img class=\"size-medium wp-image-96\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/usgs_terranes-179x300.gif\" alt=\"Map showing large areas of the western North American continent that are accreted.\" width=\"179\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2526\" class=\"wp-caption-text\">Accreted terranes of western North America. Everything that is not the \"Ancient continental interior (craton)\" has been smeared onto the side of the continent by accretion from subduction.<\/figcaption><\/figure>\n<p>When the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducting<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>, or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a>, sinks into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>, the immense heat and pressure pushes volatile materials like water and carbon dioxide into an area below the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> and above the descending <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> called the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1685\">mantle wedge<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1684\">volatiles<\/a> are released mostly by hydrated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that revert to non-hydrated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> in these higher <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> and pressure conditions. When mixed with asthenospheric material above the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>, the volatile lower the melting point of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1685\">mantle wedge<\/a>, and through a process called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1686\">flux melting<\/a> it becomes liquid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>. The molten <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> is more buoyant than the lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> above it and migrates to the Earth\u2019s surface where it emerges as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a>. The resulting <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanoes<\/a> frequently appear as curved mountain chains, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> arcs, due to the curvature of the earth. Both <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> can contain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> arcs.<\/p>\n<figure id=\"attachment_2527\" aria-describedby=\"caption-attachment-2527\" style=\"width: 236px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/1755_Lisbon_Earthquake_Location.png\"><img class=\"size-medium wp-image-97\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/1755_Lisbon_Earthquake_Location-236x300.png\" alt=\"It is large and offshore.\" width=\"236\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2527\" class=\"wp-caption-text\">Location of the large (Mw 8.5-9.0) 1755 Lisbon Earthquake.<\/figcaption><\/figure>\n<p>How <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> is initiated is still a matter of scientific debate. It is generally accepted that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zones start as passive margins, where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a>\u00a0and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> come together, and then gravity initiates <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> and converts the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1676\">passive margin<\/a> into an active one. One <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> is gravity pulls the denser <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> down or the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> can start to flow ductility at a low angle. Scientists seeking to answer this question have collected evidence that suggests a new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zone is forming off the coast\u00a0of Portugal. Some scientists have proposed large earthquakes like the 1755 Lisbon earthquake may even have something to do with this process of creating a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zone, although the evidence is not definitive. Another <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> proposes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> happens at <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> boundaries involving <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> of different densities.<\/p>\n<p>Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> boundaries look like they should be active, but show no evidence of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> on either side of the Atlantic Ocean for example, are denser than the underlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a> and are not <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducting<\/a> beneath the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. One <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> is the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1781\">bond<\/a> holding the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> together is stronger than the downwards force created by the difference in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> densities.<\/p>\n<figure id=\"attachment_2528\" aria-describedby=\"caption-attachment-2528\" style=\"width: 234px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/SundaMegathrustSeismicity.png\"><img class=\"size-medium wp-image-98\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/SundaMegathrustSeismicity-234x300.png\" alt=\"The earthquakes follow the slab down.\" width=\"234\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2528\" class=\"wp-caption-text\">Earthquakes along the Sunda megathrust subduction zone, along the island of Sumatra, showing the 2006 Mw 9.1-9.3 Indian Ocean Earthquake as a star.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">Subduction<\/a> zones are known for having the largest earthquakes and tsunamis; they are the only places with fault surfaces large enough to create magnitude-9 earthquakes. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a>-zone earthquakes not only are very large, but also are very deep. When a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducting<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a> becomes stuck and cannot descend, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_985\">massive<\/a> amount of energy builds up between the stuck <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. If this energy is not gradually dispersed, it may force the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> to suddenly release along several hundred kilometers of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zone. Because <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a>-zone faults are located on the ocean floor, this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_985\">massive<\/a> amount of movement can generate giant tsunamis such as those that followed the 2004 Indian Ocean Earthquake and 2011 T\u014dhoku Earthquake in Japan.<\/p>\n<figure id=\"attachment_2529\" aria-describedby=\"caption-attachment-2529\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Forearc.gif\"><img class=\"size-medium wp-image-99\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Forearc-300x258.gif\" alt=\"It shows backarc, forearc, and arc.\" width=\"300\" height=\"258\"><\/a><figcaption id=\"caption-attachment-2529\" class=\"wp-caption-text\">Various parts of a subduction zone. This subduction zone is ocean-ocean subduction, though the same features can apply to continent-ocean subduction.<\/figcaption><\/figure>\n<p>All <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zones have a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1692\">forearc basin<\/a>, a feature of the overriding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> found between the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1695\">volcanic arc<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1681\">trench<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1692\">forearc basin<\/a> experiences a lot of faulting\u00a0and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_495\">deformation<\/a> activity, particularly within the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1682\">accretionary wedge<\/a>.<\/p>\n<p>In some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zones, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">tensional<\/a> forces\u00a0working on the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> create a backarc <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> on the interior side of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1695\">volcanic arc<\/a>. Some scientists have proposed a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> mechanism called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a> rollback creates <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">extension<\/a> faults in the overriding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. In this model, the descending <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a> does not slide directly under the overriding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> but instead rolls back, pulling the overlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> seaward. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> behind the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1695\">volcanic arc<\/a> gets stretched like pizza dough until the surface cracks and collapses to form a backarc <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a>. If the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">extension<\/a> activity is extensive and deep enough, a backarc <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> can develop into a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> zone. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundaries may be less symmetrical than their <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridge<\/a> counterparts.<\/p>\n<p>In places where numerous young buoyant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> are converging and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducting<\/a> at a relatively high velocity, they may force the overlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> to buckle and crack. This is called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1688\">back-arc<\/a> faulting. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">Extensional<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1688\">back-arc<\/a> faults pull rocks and chunks of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> apart. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_493\">Compressional<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1688\">back-arc<\/a> faults, also known as thrust faults, push them together.<\/p>\n<p>The dual spines of the Andes Mountain range include a example of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_493\">compressional<\/a> thrust faulting. The western spine is part of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1695\">volcanic arc<\/a>. Thrust faults have deformed the non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> eastern spine, \u00a0pushing rocks and pieces of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> on top of each other.<\/p>\n<p>There are two styles of thrust fault <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_495\">deformation<\/a>: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1689\">thin-skinned<\/a> faults that occur in superficial rocks lying on top of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1690\">thick-skinned<\/a> faults that reach deeper into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>. The Sevier <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1663\">Orogeny<\/a> in the western U.S. is a notable <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1689\">thin-skinned<\/a> type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_495\">deformation<\/a> created during the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_487\">Cretaceous<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">Period<\/a>. The Laramide <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1663\">Orogeny<\/a>, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1690\">thick-skinned<\/a> type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_495\">deformation<\/a>, occurred near the end of and slightly after the Sevier <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1663\">Orogeny<\/a> \u00a0in the same region.<\/p>\n<figure id=\"attachment_2530\" aria-describedby=\"caption-attachment-2530\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Shallow_subduction_Laramide_orogeny.png\"><img class=\"size-medium wp-image-100\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Shallow_subduction_Laramide_orogeny-300x142.png\" alt=\"The subducting plate goes right under the overriding plate\" width=\"300\" height=\"142\"><\/a><figcaption id=\"caption-attachment-2530\" class=\"wp-caption-text\">Shallow subduction during the Laramide Orogeny.<\/figcaption><\/figure>\n<p>Flat-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a>, or shallow, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> caused the Laramide <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1663\">Orogeny<\/a>. When the descending <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducts<\/a> at a low angle, there is more contact between the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a> and the overlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> than in a typical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zone. The shallowly-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducting<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a> pushes against the overriding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> and creates an area of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_495\">deformation<\/a> on the overriding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> many kilometers away from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zone.<\/p>\n<h4><span style=\"font-weight: 400;\">Oceanic-Continental subduction<\/span><\/h4>\n<figure id=\"attachment_2531\" aria-describedby=\"caption-attachment-2531\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/OceanContSub.gif\"><img class=\"size-medium wp-image-101\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/OceanContSub-300x177.gif\" alt=\"The thinner ocean plate is going under the thicker continental plate.\" width=\"300\" height=\"177\"><\/a><figcaption id=\"caption-attachment-2531\" class=\"wp-caption-text\">Subduction of an oceanic plate beneath a continental plate, forming a trench and volcanic arc.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1694\">Oceanic-continental subduction<\/a> occurs when an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> dives below a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>. This <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1678\">convergent<\/a> boundary has a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1681\">trench<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1685\">mantle wedge<\/a> and frequently, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1695\">volcanic arc<\/a>. Well-known examples of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1695\">volcanic arcs<\/a> are the Cascade Mountains in the Pacific Northwest and western Andes Mountains in South America.<\/p>\n<h4><span style=\"font-weight: 400;\">Oceanic-Oceanic Subduction<\/span><\/h4>\n<figure id=\"attachment_2532\" aria-describedby=\"caption-attachment-2532\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Fig21oceanocean.gif\"><img class=\"size-medium wp-image-102\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Fig21oceanocean-300x173.gif\" alt=\"The ocean plate subducts beneath a different ocean plate.\" width=\"300\" height=\"173\"><\/a><figcaption id=\"caption-attachment-2532\" class=\"wp-caption-text\">Subduction of an oceanic plate beneath another oceanic plate, forming a trench and an island arc.<\/figcaption><\/figure>\n<p>The boundaries of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1696\">oceanic-oceanic subduction<\/a> zones show very different activity from those involving <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a>-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. Since both <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> are made of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>, it is usually the older <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducts<\/a> because it is colder and denser. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> on the overlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> may remain hidden underwater.. If the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanoes<\/a> rise high enough the reach the ocean surface, the chain of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> forms an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1697\">island arc<\/a>. Examples of these island arcs include the Aleutian Islands in the northern Pacific Ocean, Lesser Antilles in the Caribbean Sea, and numerous island chains scattered throughout the western Pacific Ocean.<\/p>\n<h3><b>2.3.2. Collisions<\/b><\/h3>\n<figure id=\"attachment_2533\" aria-describedby=\"caption-attachment-2533\" style=\"width: 301px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/contcontCollision.gif\"><img class=\"size-full wp-image-103\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/contcontCollision.gif\" alt=\"The two continental plates stay up.\" width=\"301\" height=\"181\"><\/a><figcaption id=\"caption-attachment-2533\" class=\"wp-caption-text\">Two continental plates colliding.<\/figcaption><\/figure>\n<p>When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> converge, during the closing of an ocean <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> for example, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> is not possible between the equally buoyant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. Instead of one <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> descending beneath another, the two masses of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> slam together in a process known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a>. Without <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a>, there is no <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> formation and no <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">Collision<\/a> zones are characterized by tall, non-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> mountains; a broad zone of frequent, large earthquakes; and very little <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a>.<\/p>\n<p>When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic crust<\/a> connected by a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1676\">passive margin<\/a> to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental crust<\/a> completely <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducts<\/a> beneath a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continent<\/a>, an ocean <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> closes, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a> begins. \u00a0Eventually, as ocean basins close, continents join together to form a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_985\">massive<\/a> accumulation of continents called a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1701\">supercontinent<\/a>, a process that has taken place in ~500 million year old cycles over earth\u2019s history.<\/p>\n<figure id=\"attachment_2534\" aria-describedby=\"caption-attachment-2534\" style=\"width: 267px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Pangaea_continents.png\"><img class=\"size-medium wp-image-104\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Pangaea_continents-267x300.png\" alt=\"Pangaea has a crescent shape.\" width=\"267\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2534\" class=\"wp-caption-text\">A reconstruction of Pangaea, showing approximate positions of modern continents.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The process of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a> created Pangea, the supercontinent envisioned by Wegener as the key component of his <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> drift <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a>. Geologists now have evidence that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> have been continuously converging into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1701\">supercontinents<\/a> and splitting into smaller <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a>-separated continents throughout Earth\u2019s existence, calling this process the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1701\">supercontinent<\/a> cycle, a process that takes place in approximately 500 million years. For example, they estimate Pangea began separating 200 million years ago. Pangea was preceded by an earlier <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1701\">supercontinents<\/a>, one of which being <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1263\">Rodinia<\/a>, which existed 1.1 billion years ago and started breaking apart 800 million to 600 million years ago.<\/p>\n<figure id=\"attachment_2535\" aria-describedby=\"caption-attachment-2535\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/ZagrosFTB.png\"><img class=\"size-medium wp-image-105\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/ZagrosFTB-300x231.png\" alt=\"The mountains are loading the crust down, leading to a depressed basin, which is the Persian Gulf\" width=\"300\" height=\"231\"><\/a><figcaption id=\"caption-attachment-2535\" class=\"wp-caption-text\">The tectonics of the Zagros Mountains. Note the Persian Gulf foreland basin.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>A foreland <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> is a feature that develops near mountain belts, as the combined mass of the mountains forms a depression in the lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>. While foreland basins may occur at <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zones, they are most commonly found at <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a> boundaries. The Persian Gulf is possibly the best modern example, created entirely by the weight of the nearby Zagros Mountains.<\/p>\n<figure id=\"attachment_2536\" aria-describedby=\"caption-attachment-2536\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/02.3_ItalyPillowBasalt.jpg\"><img class=\"size-medium wp-image-106\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/02.3_ItalyPillowBasalt-300x225.jpg\" alt=\"The rock is cray with many circles inside\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-2536\" class=\"wp-caption-text\">Pillow lavas, which only form under water, from an ophiolite in the Apennine Mountains of central Italy.<\/figcaption><\/figure>\n<p>If <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> are fused on the same <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>, it can partially subduct but its buoyancy prevents it from fully descending. In very rare cases, part of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> may become trapped beneath a descending <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> in a process called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1699\">obduction<\/a>. When a portion of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental crust<\/a> is driven down into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zone, due to its buoyancy it returns to the surface relatively quickly.<\/p>\n<p>As pieces of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> break loose and migrate upward through the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1699\">obduction<\/a> zone, they bring along bits of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> and ocean floor and amend them on top of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>. Rocks composed of this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> and ocean-floor material are called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1700\">ophiolites<\/a> and they provide valuable information about the composition of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>.<\/p>\n<p>The area of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a>-zone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_495\">deformation<\/a> and seismic activity usually covers a broader area because <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> is plastic and malleable. Unlike <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a>-zone earthquakes, which tend to be located along a narrow swath near the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1678\">convergent<\/a> boundary, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a>-zone earthquakes may occur hundreds of kilometers from the boundary between the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>.<\/p>\n<p>The Eurasian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continent<\/a> has many examples of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1698\">collision<\/a>-zone deformations covering vast areas. The Pyrenees mountains begin in the Iberian Peninsula and cross into France. Also, there are the Alps stretching from Italy to central Europe; the Zagros mountains from Arabia to Iran; and Himalaya mountains from the Indian subcontinent to central Asia.<\/p>\n<div style=\"width: 720px;\" class=\"wp-video\"><video class=\"wp-video-shortcode\" id=\"video-233-2\" width=\"720\" height=\"478\" preload=\"metadata\" controls=\"controls\"><source type=\"video\/mp4\" src=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/IndiaAsiaCollision.mp4?_=2\" \/><a href=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/IndiaAsiaCollision.mp4\">http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/IndiaAsiaCollision.mp4<\/a><\/video><\/div>\n<p><em>Animation of India crashing into Asia, by Tanya Atwater.<\/em><\/p>\n<figure id=\"attachment_3733\" aria-describedby=\"caption-attachment-3733\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/India-Asia-Collision-Animation-QR-Code.png\"><img class=\"size-thumbnail wp-image-107\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/India-Asia-Collision-Animation-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3733\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this animation via this QR Code.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-12\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-12\" class=\"h5p-iframe\" data-content-id=\"12\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2.3 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3732\" aria-describedby=\"caption-attachment-3732\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/2.3-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-108\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/2.3-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3732\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 2.3 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400;\">2.4 Divergent Boundaries<\/span><\/h2>\n<p>At <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundaries, sometimes called constructive boundaries, lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> move away from each other. There are two types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundaries, categorized by where they occur: <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> zones and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">Continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> zones occur in weak spots in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>. A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridge<\/a> usually originates in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> as a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> zone that expands to the point of splitting the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> apart, with seawater filling in the gap. The separate pieces continue to drift apart and become individual continents. This process is known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a>-to-drift.<\/p>\n<h3><b>2.4.1. Continental Rifting<\/b><\/h3>\n<figure id=\"attachment_2537\" aria-describedby=\"caption-attachment-2537\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Horst-Graben.svg_.png\"><img class=\"size-medium wp-image-109\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Horst-Graben.svg_-300x154.png\" alt=\"While the area extends, individual grabens drop down relative to the horsts.\" width=\"300\" height=\"154\"><\/a><figcaption id=\"caption-attachment-2537\" class=\"wp-caption-text\">Faulting that occurs in divergent boundaries.<\/figcaption><\/figure>\n<p>In places where the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> are very thick, they reflect so much heat back into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> it develops strong <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1655\">convection<\/a> currents that push super-heated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> material up against the overlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>, softening it. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">Tensional<\/a> forces created by this convective upwelling begin to pull the weakened <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> apart. As it stretches, it becomes thinner and develops deep cracks called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">extension<\/a> or normal faults. Eventually plate sections located between large faults drop into deep depressions known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> valleys, which often contain keystone-shaped blocks of down-dropped <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1704\">grabens<\/a>. The shoulders of these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1704\">grabens<\/a> are called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1703\">horsts<\/a>. If only one side of a section drops, it is called a half-graben. Depending on the conditions, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifts<\/a> can grow into very large lakes and even oceans.<\/p>\n<figure id=\"attachment_2538\" aria-describedby=\"caption-attachment-2538\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/TopographicAfar.png\"><img class=\"size-medium wp-image-110\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/TopographicAfar-300x300.png\" alt=\"The branches of the plate boundaries are 120 degrees apart.\" width=\"300\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2538\" class=\"wp-caption-text\">The Afar Triangle (center) has the Red Sea ridge (center to upper left), Gulf of Aden ridge (center to right), and East African Rift (center to lower left) form a triple junction that are about 120\u00b0 apart.<\/figcaption><\/figure>\n<p>While seemingly occurring at random, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> is dictated by two factors. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">Rifting<\/a> does not occur in continents with older and more stable interiors, known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1718\">cratons<\/a>. When <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> does occur, the break-up pattern resembles the seams of a soccer ball, also called a truncated icosahedron. This is the most common surface-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a> pattern to develop on an evenly expanding sphere because it uses the least amount of energy.<\/p>\n<p>Using the soccer ball model, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> tends to lengthen and expand along a particular seam while fizzling out in the other directions. These seams with little or no <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> activity are called failed rift arms. A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1705\">failed rift arm<\/a> is still a weak spot in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>; even without the presence of active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">extension<\/a> faults, it may develop into a called an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1706\">aulacogen<\/a>. One example of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1705\">failed rift arm<\/a> is the Mississippi Valley Embayment, a depression through which the upper end of the Mississippi River flows. Occasionally connected <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> arms do develop concurrently, creating multiple boundaries of active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a>. In places where the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> arms do not fail, for example the Afar Triangle, three <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundaries can develop near each other forming a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1707\">triple junction<\/a>.<\/p>\n<figure id=\"attachment_2539\" aria-describedby=\"caption-attachment-2539\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Basin_range_province.jpg\"><img class=\"size-medium wp-image-111\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Basin_range_province-300x240.jpg\" alt=\"There is a series of mountains and valleys\" width=\"300\" height=\"240\"><\/a><figcaption id=\"caption-attachment-2539\" class=\"wp-caption-text\">NASA image of the Basin and Range horsts and grabens across central Nevada.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">Rifts<\/a> come in two types: narrow and broad. Narrow <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifts<\/a> are characterized by a high density of highly active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundaries. The East African <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">Rift<\/a> Zone, where the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1531\">horn<\/a> of Africa is pulling away from the mainland, is an excellent example of an active narrow <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a>. Lake Baikal in Russia is another. Broad <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifts<\/a> also have numerous fault zones, but they are distributed over wide areas of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_495\">deformation<\/a>. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1514\">Basin and Range<\/a> region located in the western United States is a type of broad <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a>. The Wasatch Fault, which also created the Wasatch Mountain Range in the state of Utah, forms the eastern <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundary of this broad <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a>\u00a0 (<a href=\"https:\/\/youtu.be\/TvvWqAdNV84\">Animation 1<\/a> and <a href=\"https:\/\/youtu.be\/7DxcAMmNeZk\">Animation 2<\/a>).<\/p>\n<p>&nbsp;<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">Rifts<\/a> have earthquakes, although not of the magnitude and frequency of other boundaries. They may also exhibit <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a>. Unlike the flux-melted <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zones, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a>-zone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> is created by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_223\">decompression melting<\/a>. As the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> are pulled apart, they create a region of low pressure that melts the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> and draws it upwards. When this molten <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> reaches the weakened and fault-riddled <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> zone, it migrates to surface by breaking through the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> or escaping via an open fault. Examples of young <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanoes<\/a> dot the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1514\">Basin and Range<\/a> region in the United States. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">Rift<\/a>-zone activity is responsible for generating some unique <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a>, such as the Ol Doinyo Lengai in Tanzania. This <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcano<\/a> erupts <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a> consisting largely of carbonatite, a relatively cold, liquid <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>.<\/p>\n<div style=\"width: 720px;\" class=\"wp-video\"><video class=\"wp-video-shortcode\" id=\"video-233-3\" width=\"720\" height=\"474\" preload=\"metadata\" controls=\"controls\"><source type=\"video\/mp4\" src=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/SoAtlantic_CutwithConvect.mp4?_=3\" \/><a href=\"http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/SoAtlantic_CutwithConvect.mp4\">http:\/\/opengeology.org\/textbook\/wp-content\/uploads\/2016\/07\/SoAtlantic_CutwithConvect.mp4<\/a><\/video><\/div>\n<p>South America and Africa <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a>, forming the Atlantic. <a href=\"http:\/\/emvc.geol.ucsb.edu\/2_infopgs\/IP1GTect\/eSoAtlantic_CutGlobe.html\">Video<\/a> by Tanya Atwater.<\/p>\n<figure id=\"attachment_3731\" aria-describedby=\"caption-attachment-3731\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Rift-Atlantic-Animation-QR-Code.png\"><img class=\"size-thumbnail wp-image-112\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Rift-Atlantic-Animation-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3731\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this video via this QR Code.<\/figcaption><\/figure>\n<h3><b>2.4.2. Mid-ocean ridges<\/b><\/h3>\n<figure id=\"attachment_2541\" aria-describedby=\"caption-attachment-2541\" style=\"width: 212px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Ocean-birth.svg_.png\"><img class=\"size-medium wp-image-113\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ocean-birth.svg_-212x300.png\" alt=\"The ocean starts as a valley and then gets wider and wider.\" width=\"212\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2541\" class=\"wp-caption-text\">Progression from rift to mid-ocean ridge.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">As <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> activity progress, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> becomes more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">mafic<\/a> (see <a href=\"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/chapter\/4-igneous-processes-and-volcanoes\/\" target=\"_blank\" rel=\"noopener\">Chapter 4<\/a>) and thinner, with the eventual result transforming the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> under the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> area into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>. This is the process that gives birth to a new ocean, much like the narrow Red Sea emerged with the movement of Arabia away from Africa. As the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> continues to diverge, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridge<\/a> is formed.<\/span><\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">Mid-ocean ridges<\/a>, also known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">spreading centers<\/a>, have several distinctive features. They are the only places on earth that create new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_223\">Decompression melting<\/a> in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> zone changes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a> material into new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>, which oozes up through cracks in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>. The amount of new <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> being created at <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> is highly significant. These undersea <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanoes<\/a> produce more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">lava<\/a> than all other types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> combined. Despite this, most mid-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> ridge <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> remains unmapped because the volcanoes are located deep on the ocean floor.<\/p>\n<p>In rare cases, such as a few locations in Iceland, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rift<\/a> zones display the type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a>, spreading, and ridge formation found on the ocean floor.<\/p>\n<figure id=\"attachment_2542\" aria-describedby=\"caption-attachment-2542\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/age_oceanic_lith.jpg\"><img class=\"size-medium wp-image-114\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/age_oceanic_lith-300x191.jpg\" alt=\"The map shoes colors that represent different ages.\" width=\"300\" height=\"191\"><\/a><figcaption id=\"caption-attachment-2542\" class=\"wp-caption-text\">Age of oceanic lithosphere, in millions of years. Notice the differences in the Atlantic Ocean along the coasts of the continents.<\/figcaption><\/figure>\n<p>The ridge feature is created by the accumulation of hot <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> material, which is lighter than the dense underlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a>. This chunk of isostatically buoyant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> sits partially submerged and partially exposed on the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a>, like an ice cube floating in a glass of water.<\/p>\n<p>As the ridge continues to spread, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> material is pulled away from the area of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> and becomes colder and denser. As it continues to spread and cool, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> settles into wide swathes of relatively featureless topography called abyssal plains with lower topography.<\/p>\n<p>This model of ridge formation suggests the sections of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a> furthest away from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> will be the oldest. Scientists have tested this idea by comparing the age of rocks located in various locations on the ocean floor. Rocks found near ridges are younger than those found far away from any ridges. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">Sediment<\/a> accumulation patterns also confirm the idea of sea-floor spreading. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">Sediment<\/a> layers tend to be thinner near <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a>, indicating it has had less time to build up.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2543\" aria-describedby=\"caption-attachment-2543\" style=\"width: 600px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/atwater_mag_reversal_mid_ocean_ridge.gif\"><img class=\"wp-image-115 size-full\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/atwater_mag_reversal_mid_ocean_ridge.gif\" alt=\"animation showing the mid ocean ridges. As new oceanic plate is made at the ridge, it cools and preserves the current magnetic field at the time of cooling. When the poles reverse, the magnetic polarity flip is preserved in the oceanic plate record.\" width=\"600\" height=\"400\"><\/a><figcaption id=\"caption-attachment-2543\" class=\"wp-caption-text\">Spreading along several mid-ocean ridges, showing magnetic striping symmetry. By Tanya Atwater.<\/figcaption><\/figure>\n<figure id=\"attachment_3743\" aria-describedby=\"caption-attachment-3743\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Atwater-Spreading-GIF.png\"><img class=\"size-thumbnail wp-image-116\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Atwater-Spreading-GIF-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3743\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this animation via this QR Code.<\/figcaption><\/figure>\n<p>As mentioned in the section on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1657\">paleomagnetism<\/a> and the development of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a>, scientists noticed <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> contained unique magnetic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_765\">anomalies<\/a> that show up as symmetrical striping on both sides of the ridge. The Vine-Matthews-Morley <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> proposes these alternating reversals are created by the earth\u2019s magnetic field being imprinted into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a><\/p>\n<figure id=\"attachment_2544\" aria-describedby=\"caption-attachment-2544\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Oceanic.Stripe.Magnetic.Anomalies.Scheme.svg_.png\"><img class=\"size-medium wp-image-117\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Oceanic.Stripe.Magnetic.Anomalies.Scheme.svg_-300x212.png\" alt=\"The older stripes are farther from the ridge.\" width=\"300\" height=\"212\"><\/a><figcaption id=\"caption-attachment-2544\" class=\"wp-caption-text\">A time progression (with \"a\" being youngest and \"c\" being oldest) showing a spreading center getting wider while recording changes in the magnetic field of the Earth.<\/figcaption><\/figure>\n<p>after it emerges from the ridge. Very hot <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> has no magnetic field. As the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> get pulled apart, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> cools below the Curie point, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> below which a magnetic field gets locked into magnetic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. The alternating magnetic reversals in the rocks reflects the periodic swapping of earth\u2019s magnetic north and south poles. This paleomagnetic pattern provides a great historical record of ocean-floor movement, and is used to reconstruct past <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> activity and determine rates of ridge spreading.<\/p>\n<p><em><a href=\"http:\/\/emvc.geol.ucsb.edu\/2_infopgs\/IP3RegTect\/bNoCentAtlantic.html\">Video<\/a> of the breakup of <em>Pangea<\/em> and <em>formation<\/em> of the northern Atlantic Ocean. By Tanya Atwater.<\/em><\/p>\n<figure id=\"attachment_3729\" aria-describedby=\"caption-attachment-3729\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Pangea-Animation-QR-Code.png\"><img class=\"size-thumbnail wp-image-118\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Pangea-Animation-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3729\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this video via this QR Code.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2545\" aria-describedby=\"caption-attachment-2545\" style=\"width: 233px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/BlackSmoker.jpg\"><img class=\"wp-image-119 size-medium\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/BlackSmoker-233x300.jpg\" alt=\"There is a large build up of minerals around the vent\" width=\"233\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2545\" class=\"wp-caption-text\">Black smoker hydrothermal vent with a colony of giant (6'+) tube worms.<\/figcaption><\/figure>\n<p>Thanks to their distinctive geology, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> are home to some of the most unique ecosystems ever discovered. The ridges are often studded with hydrothermal vents, deep fissures that allow seawater to circulate through the upper portions of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> and interact with hot rock. The super-heated seawater rises back up to the surface of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>, carrying dissolved gasses and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, and small particulates.\u00a0 The resulting emitted hydrothermal water looks like black underwater smoke.<\/p>\n<p>Scientists had known about these geothermal areas on the ocean floor for some time. However, it was not until 1977, when scientists piloting a deep submergence vehicle, the Alvin, discovered a thriving community of organisms clustered around these hydrothermal vents. These unique organisms, which include 10-foot-long tube worms taller than people, live in the complete darkness of the ocean floor  deprived of oxygen and sunlight. They use geothermal energy provided by the vents and a process called bacterial <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_231\">chemosynthesis<\/a> to feed on sulfur compounds. Before this discovery, scientists believed life on earth could not exist without photosynthesis, a process that requires sunlight. Some scientists suggest this type of environment could have been the origin of life on Earth, and perhaps even extraterrestrial life elsewhere in the galaxy, such as on Jupiter\u2019s moon Europa.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-13\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-13\" class=\"h5p-iframe\" data-content-id=\"13\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2.4 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3728\" aria-describedby=\"caption-attachment-3728\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/2.4-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-120\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/2.4-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3728\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 2.4 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400;\">2.5 Transform Boundaries<\/span><\/h2>\n<figure id=\"attachment_2546\" aria-describedby=\"caption-attachment-2546\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Strike_slip_fault.png\"><img class=\"size-medium wp-image-121\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Strike_slip_fault-300x137.png\" alt=\"Sinistral moves to the left, dextral moves to the right.\" width=\"300\" height=\"137\"><\/a><figcaption id=\"caption-attachment-2546\" class=\"wp-caption-text\">The two types of transform\/strike slip faults.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> boundary, sometimes called a strike-slip or conservative boundary, is where the lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> slide past each other in the horizontal plane. This movement is described based on the perspective of an observer standing on one of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>, looking across the boundary at the opposing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>. Dextral, also known as right-lateral, movement describes the opposing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> moving to the right. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1710\">Sinistral<\/a>, also known as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1710\">left lateral<\/a>, movement describe the opposing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> moving to the left.<\/p>\n<p>Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> boundaries are found on the ocean floor, around <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a>. These boundaries form aseismic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fracture<\/a> zones, filled with earthquake-free <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> faults, to accommodate different rates of spreading occurring at the ridge.<\/p>\n<figure id=\"attachment_2547\" aria-describedby=\"caption-attachment-2547\" style=\"width: 217px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Sanandreas.jpg\"><img class=\"size-medium wp-image-122\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Sanandreas-217x300.jpg\" alt=\"The fault runs through California.\" width=\"217\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2547\" class=\"wp-caption-text\">Map of the San Andreas fault, showing relative motion.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Some <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> boundaries produce significant seismic activity, primarily as earthquakes, with very little mountain-building or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a>. This type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> boundary may contain a single fault or series of faults, which develop in places where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> stresses are transferred to the surface. As with other types of active boundaries, if the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> are unable to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_494\">shear<\/a> past each other the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> forces will continue to build up. If the built up energy between the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> is suddenly released, the result is an earthquake.<\/p>\n<p>In the eyes of humanity, the most significant <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> faults occur within <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>, and have a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_494\">shearing<\/a> motion that frequently produces moderate-to-large magnitude earthquakes. Notable examples include the San Andreas Fault in California, Northern and Eastern Anatolian Faults\u00a0in Turkey, Altyn Tagh Fault in central Asia, and Alpine Fault in New Zealand.<\/p>\n<h3><b>2.5.1. Transpression and Transtension<\/b><\/h3>\n<figure id=\"attachment_2548\" aria-describedby=\"caption-attachment-2548\" style=\"width: 150px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Transpression.png\"><img class=\"wp-image-123 size-thumbnail\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Transpression-150x150.png\" alt=\"The fault is dextral, and has a leftward bend, causing uplift.\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-2548\" class=\"wp-caption-text\">A transpressional strike-slip fault, causing uplift called a restraining bend.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Bends along <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> faults may create <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_493\">compressional<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">extensional<\/a> forces that cause secondary faulting zones. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1712\">Transpression<\/a> occurs where there is a component of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_493\">compression<\/a> in addition to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_494\">shearing<\/a> motion. These forces build up around the area of the bend, where the opposing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> are restricted from sliding past each other. As the forces continue to build up, they create mountains in the restraining bend around the fault. The Big Bend area, located in the southern part of the San Andreas Fault includes a large area of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1712\">transpression<\/a> where many mountains have been built, moved, and even rotated.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_2549\" aria-describedby=\"caption-attachment-2549\" style=\"width: 150px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Transtension.png\"><img class=\"wp-image-124 size-thumbnail\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Transtension-150x150.png\" alt=\"The fault is dextral, and has a rightward bend, causing a valley.\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-2549\" class=\"wp-caption-text\">A transtensional strike-slip fault, causing a restraining bend. In the center of the fault, a depression with extension would be found.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1713\">Transtension<\/a> zones require a fault that includes a releasing bend, where the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> are being pulled apart by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_492\">extensional<\/a> forces. Depressions and sometimes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> develop in the releasing bend, along the fault. The Dead Sea found between Israel and Jordan, and the Salton Sea of California are examples of basins formed by transtensional forces.<\/p>\n<h3><\/h3>\n<h3><b>2.5.2. Piercing Points<\/b><\/h3>\n<figure id=\"attachment_2550\" aria-describedby=\"caption-attachment-2550\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Wallace_Creek_offset_across_the_San_Andreas_Fault.png\"><img class=\"size-medium wp-image-125\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Wallace_Creek_offset_across_the_San_Andreas_Fault-300x205.png\" alt=\"The offset is to the left.\" width=\"300\" height=\"205\"><\/a><figcaption id=\"caption-attachment-2550\" class=\"wp-caption-text\">Wallace (dry) Creek on the Cariso Plain, California. Note as the creek flows from the northern mountainous part of the image, it takes a sharp right (as viewed from the flow of water), then a sharp left. This is caused by the San Andreas Fault cutting roughly perpendicular to the creek, and shifting the location of the creek over time. The fault can be seen about halfway down, trending left to right, as a change in the topography.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>When a geological feature is cut by a fault, it is called a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1714\">piercing point<\/a>. Piercing points are very useful for recreating past fault movement, especially along <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">transform<\/a> boundaries. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\">Transform<\/a> faults are unique because their horizontal motion keeps a geological feature relatively intact, preserving the record of what happened. Other types of faults\u2014normal and reverse \u2014tend to be more destructive, obscuring or destroying these features. The best type of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1714\">piercing point<\/a> includes unique patterns that are used to match the parts of a geological feature separated by fault movement. Detailed studies of piercing points show the San Andreas Fault has experienced over 225 km of movement in the last 20 million years, and this movement occurred at three different fault traces.<\/p>\n<p><em>Video of the origin of the San Andreas <em>fault<\/em>. As the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\"><em>mid-ocean ridge<\/em><\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\"><em>subducts<\/em><\/a>, the relative motion between the remaining <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\"><em>plates<\/em><\/a> become <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1679\"><em>transform<\/em><\/a>, forming the <em>fault<\/em> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1742\"><em>system<\/em><\/a>. Note that because the motion of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\"><em>plates<\/em><\/a> is not exactly parallel to the <em>fault<\/em>, it causes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\"><em>divergent<\/em><\/a> motion in the interior of North America. By Tanya Atwater.<\/em><\/p>\n<figure id=\"attachment_3727\" aria-describedby=\"caption-attachment-3727\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Plate-Tectonics-YouTube-QR-Code.png\"><img class=\"size-thumbnail wp-image-126\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Plate-Tectonics-YouTube-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3727\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this YouTube video via this QR Code.<\/figcaption><\/figure>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-14\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-14\" class=\"h5p-iframe\" data-content-id=\"14\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2.5 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3726\" aria-describedby=\"caption-attachment-3726\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/2.5-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-127\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/2.5-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3726\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 2.5 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400;\">2.6 The Wilson Cycle<\/span><\/h2>\n<figure id=\"attachment_2551\" aria-describedby=\"caption-attachment-2551\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Wilson-cycle_hg.svg_.png\"><img class=\"size-medium wp-image-128\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Wilson-cycle_hg.svg_-300x164.png\" alt=\"The diagram shows the last 1000 million years.\" width=\"300\" height=\"164\"><\/a><figcaption id=\"caption-attachment-2551\" class=\"wp-caption-text\">Diagram of the Wilson Cycle, showing rifting and collision phases.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1715\">Wilson Cycle<\/a> is named for J. Tuzo Wilson who first described it in 1966, and it outlines the ongoing origin and breakup of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1701\">supercontinents<\/a>, such as Pangea and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1263\">Rodinia<\/a>. Scientists have determined this cycle has been operating for at least three billion years and possibly earlier.<\/p>\n<p>There are a number of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypotheses<\/a> about how the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1715\">Wilson Cycle<\/a> works. One mechanism proposes that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> happens because <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> reflect the heat much better than <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. When continents congregate together, they reflect more of the Earth\u2019s heat back into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>, generating more vigorous <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1655\">convection<\/a> currents that then start the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> process. Some geologists believe <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> plumes are remnants of these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">periods<\/a> of increased <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1655\">convection<\/a> upwelling, and study them for clues about the origin of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a>.<\/p>\n<p>The mechanism behind how <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1701\">supercontinents<\/a> are created is still largely a mystery. There are three schools of thought about what continues to drive the continents further apart and eventually bring them together. The ridge-push <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1730\">hypothesis<\/a> suggests after the initial <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> event, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> continue to be pushed apart by mid-ocean <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">spreading centers<\/a> and their underlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1655\">convection<\/a> currents. Slab-pull proposes the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> are pulled apart by descending slabs in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> zones of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a>-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> margins. A third idea, gravitational sliding, attributes the movement to gravitational forces pulling the lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> down from the elevated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> and across the underlying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1671\">asthenosphere<\/a>. Current evidence seems to support <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1683\">slab<\/a> pull more than ridge push or gravitational sliding.<\/p>\n<h2><span style=\"font-weight: 400;\">2.7 Hotspots<\/span><\/h2>\n<figure id=\"attachment_2552\" aria-describedby=\"caption-attachment-2552\" style=\"width: 193px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Hotspotgeology-1.svg_.png\"><img class=\"size-medium wp-image-129\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hotspotgeology-1.svg_-193x300.png\" alt=\"The plate is moving to the left, the magma stays in the center am makes a chain of volcanoes.\" width=\"193\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2552\" class=\"wp-caption-text\">Diagram showing a non-moving source of magma (mantle plume) and a moving overriding plate.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1715\">Wilson Cycle<\/a> provides a broad overview of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement. To analyze <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement more precisely, scientists study <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a>. First postulated by J. Tuzo Wilson in 1963, a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> is an area in the lithospheric <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> where molten <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> breaks through and creates a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> center, islands in the ocean and mountains on land. As the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> moves across the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a>, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcano<\/a> center becomes <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_755\">extinct<\/a> because it is no longer over an active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> source. Instead, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> emerges through another area in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> to create a new active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcano<\/a>. Over time, the combination of moving <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> and stationary <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> creates a chain of islands or mountains. The classic definition of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a> states they do not move, although recent evidence suggests that there may be exceptions.<\/p>\n<figure id=\"attachment_2553\" aria-describedby=\"caption-attachment-2553\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/HotspotsWorld.png\"><img class=\"size-medium wp-image-130\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/HotspotsWorld-300x175.png\" alt=\"Hotspots are scattered around the world.\" width=\"300\" height=\"175\"><\/a><figcaption id=\"caption-attachment-2553\" class=\"wp-caption-text\">Map of world hotspots. Larger circles indicate more active hotspots.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">Hotspots<\/a> are the only types of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> not associated with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subduction<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a> zones at <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> boundaries; they seem totally disconnected from any <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> processes, such as earthquakes. However, there are\u00a0 relationships between <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a>. There are several <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a>, current and former, that are believed to have begun at the time of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a>. Also, scientists use the age of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> eruptions and shape of the chain to quantify the rate and direction of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement relative to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a>.<\/p>\n<p>Scientists are divided over how <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> is generated in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a>. Some suggest that <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a> originate from super-heated material from as deep as the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1667\">core<\/a> that reaches the Earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a> as a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1717\">mantle plume<\/a>. Others argue the molten material that feeds <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a> is sourced from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>. Of course, it is difficult to collect data from these deep-Earth features due to the extremely high pressure and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a>.<\/p>\n<p>How <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a> are initiated is another highly debated subject. The prevailing mechanism has <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a> starting in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1677\">divergent<\/a> boundaries during <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1701\">supercontinent<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1702\">rifting<\/a>. Scientists have identified a number of current and past <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a> believed to have begun this way. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">Subducting<\/a> slabs have also been named as causing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> plumes and hot-spot <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a>. Some geologists have suggested another geological process not involving <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> may be involved, such as a large space objects crashing into Earth. Regardless of how they are formed, dozens are on the Earth. Some well-known examples include the Tahiti Islands, Afar Triangle, Easter Island, Iceland, Galapagos Islands, and Samoan Islands. The United States is home to two of the largest and best-studied <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a>: Hawaii and Yellowstone.<\/p>\n<h3><b>2.7.1 Hawaiian hotspot<\/b><\/h3>\n<figure id=\"attachment_2554\" aria-describedby=\"caption-attachment-2554\" style=\"width: 296px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Hawaii-Emperor_engl.png\"><img class=\"size-medium wp-image-131\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hawaii-Emperor_engl-296x300.png\" alt=\"There are a series of island and seamounts in the Pacific Ocean, with a bend in the middle.\" width=\"296\" height=\"300\"><\/a><figcaption id=\"caption-attachment-2554\" class=\"wp-caption-text\">The Hawaii-Emperor seamount and island chain.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>The active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanoes<\/a> in Hawaii represent one of the most active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> sites on earth. Scientific evidence indicates the Hawaiian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> is at least 80 million years old. Geologists believe it is actually much older; however any rocks with proof of this have been <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1680\">subducted<\/a> under the ocean floor. The big island of Hawaii sits atop a large <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1717\">mantle plume<\/a> that marks the active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a>. The Kilauea <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcano<\/a> is the main <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_234\">vent<\/a> for this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> and has been actively erupting since 1983.<\/p>\n<p>This enormous <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> island chain, much of which is underwater, stretches across the Pacific for almost 6,000 km. The seamount chain\u2019s most striking feature is a sharp 60-degree bend located at the midpoint, which marks a significant change in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement direction that occurred 50 million years ago. The change in direction has been more often linked to a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> reconfiguration, but also to other things like plume migration.<\/p>\n<figure id=\"attachment_2555\" aria-describedby=\"caption-attachment-2555\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Hawaii_hotspot_cross-sectional_diagram.jpg\"><img class=\"size-medium wp-image-132\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hawaii_hotspot_cross-sectional_diagram-300x159.jpg\" alt=\"The islands get older to the left.\" width=\"300\" height=\"159\"><\/a><figcaption id=\"caption-attachment-2555\" class=\"wp-caption-text\">Diagram of the Hawaiian hotspot and islands that it formed.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>In an attempt to map the Hawaiian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1717\">mantle plume<\/a> as far down as the lower <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a>, scientists have used tomography, a type of three-dimensional seismic imaging. This information\u2014along with other evidence gathered from rock ages, vegetation types, and island size\u2014indicate the oldest islands in the chain are located the furthest away from the active <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a>.<\/p>\n<h4><b>2.7.2 Yellowstone hotspot<\/b><\/h4>\n<figure id=\"attachment_2556\" aria-describedby=\"caption-attachment-2556\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/YellowstoneHotspot.jpg\"><img class=\"size-medium wp-image-133\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/YellowstoneHotspot-300x206.jpg\" alt=\"The hotspot started near the Idaho-Oregon-Nevada boarder, then moved toward its present location neat the Wyoming-Idaho-Montana boarder.\" width=\"300\" height=\"206\"><\/a><figcaption id=\"caption-attachment-2556\" class=\"wp-caption-text\">The track of the Yellowstone hotspot, which shows the age of different eruptions in millions of years ago.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Like the Hawaiian version, the Yellowstone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> is formed by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> rising through the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>. What makes it different is this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> is located under a thick, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>. Hawaii sits on a thin <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1659\">oceanic<\/a>\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a>, which is easily breached by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> coming to the surface. At Yellowstone, the thick <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1653\">continental<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> presents a much more difficult barrier for <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> to penetrate. When it does emerge, the eruptions are generally much more violent. Thankfully they are also less frequent.<\/p>\n<p>Over 15 million years of eruptions by this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> have carved a curved path across the western United States. It has been suggested the Yellowstone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> is connected to the much older Columbia River <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_244\">flood basalts<\/a> and even to 70 million-year-old <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanism<\/a> found in the Yukon region of Canada.<\/p>\n<figure id=\"attachment_2557\" aria-describedby=\"caption-attachment-2557\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/09\/Yellowstone_volcano_-_ash_beds.jpg\"><img class=\"size-medium wp-image-134\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Yellowstone_volcano_-_ash_beds-300x195.jpg\" alt=\"The eruptions trend eastward due to prevailing winds.\" width=\"300\" height=\"195\"><\/a><figcaption id=\"caption-attachment-2557\" class=\"wp-caption-text\">Several prominent ash beds found in North America, including three Yellowstone eruptions shaded pink (Mesa Falls, Huckleberry Ridge, and Lava Creek), the Bisho Tuff ash bed (brown dashed line), and the modern May 18th, 1980 ash fall (yellow).<\/figcaption><\/figure>\n<p>The most recent major eruption of this <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> created the Yellowstone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_235\">Caldera<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1751\">Lava<\/a> Creek <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1005\">tuff<\/a> formation approximately 631,000 years ago. The eruption threw 1,000 cubic kilometers of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1001\">ash<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> into the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a>, some of which was found as far away as Mississippi. Should the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspot<\/a> erupt again, scientists predict it will be another <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_985\">massive<\/a> event. This would be a calamity reaching far beyond the western United States. These super <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> eruptions fill the earth\u2019s <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a> with so much gas and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1001\">ash<\/a>, they block sunlight from reaching the earth. Not only would this drastically alter climates and environments around the globe, it could affect worldwide food production.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-15\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-15\" class=\"h5p-iframe\" data-content-id=\"15\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2.6\/7 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3725\" aria-describedby=\"caption-attachment-3725\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/2.6-7-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-135\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/2.6-7-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3725\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for sections 2.6 and 2.7 via this QR Code.<\/figcaption><\/figure>\n<h2><\/h2>\n<h2>Summary<\/h2>\n<figure id=\"attachment_3724\" aria-describedby=\"caption-attachment-3724\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Plate-Tectonics-Basics-YouTube-QR-Code.png\"><img class=\"size-thumbnail wp-image-136\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Plate-Tectonics-Basics-YouTube-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3724\" class=\"wp-caption-text\">If you are using the printed version of this OER, access this YouTube video via this QR Code.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">Plate tectonics<\/a> is a unifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a>; it explains nearly all of the major geologic processes on Earth. Since its early inception in the 1950s and 1960s, geologists have been guided by this revolutionary perception of the world. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1733\">theory<\/a> of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">plate tectonics<\/a> states the surface layer of the Earth is broken into a network of solid, relatively <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1661\">brittle<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a>. Underneath the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> is a much hotter and more <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1660\">ductile<\/a> layer that contains zones of convective upwelling generated by the interior heat of Earth. These <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1655\">convection<\/a> currents move the surface <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> around\u2014bringing them together, pulling them apart, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_494\">shearing<\/a> them side-by-side. Earthquakes and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanoes<\/a> form at the boundaries where the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plates<\/a> interact, with the exception of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1716\">hotspots<\/a>, which are not caused by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1669\">plate<\/a> movement.<\/p>\n<p>&nbsp;<\/p>\n<h3>Take this quiz to check your comprehension of this Chapter.<\/h3>\n<div id=\"h5p-16\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-16\" class=\"h5p-iframe\" data-content-id=\"16\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Chapter 2 Review\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_3723\" aria-describedby=\"caption-attachment-3723\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2021\/12\/Ch.2-Review-QR-Code.png\"><img class=\"size-thumbnail wp-image-137\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.2-Review-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-3723\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the review quiz for Chapter 2 via this QR Code.<\/figcaption><\/figure>\n<h2>References<\/h2>\n<div class=\"csl-bib-body\">\n<ol>\n<li class=\"csl-entry\">Aitta, A., 2006, Iron melting curve with a tricritical point: J. 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[<a href=\"http:\/\/www.gnu.org\/copyleft\/fdl.html\">GFDL<\/a>, <a href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/\">CC-BY-SA-3.0<\/a> or <a href=\"http:\/\/creativecommons.org\/licenses\/by\/2.5\">CC BY 2.5<\/a>], <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File%3AMarblequarry.JPG\">via Wikimedia Commons<\/a><\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1006\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1006\"><div tabindex=\"-1\"><p>A process where an oceanic plate descends bellow a less dense plate, causing the removal of the plate from the surface. Subduction causes the largest earthquakes possible, as the subducting plate can lock as it goes down. Volcanism is also caused as the plate releases volatiles into the mantle, causing melting.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_968\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_968\"><div tabindex=\"-1\"><p>By Matt Affolter(QFL247) (talk) (Transferred by Citypeek\/Original uploaded by Matt Affolter(QFL247)) [<a href=\"http:\/\/creativecommons.org\/licenses\/by-sa\/3.0\">CC BY-SA 3.0<\/a> or <a href=\"http:\/\/www.gnu.org\/copyleft\/fdl.html\">GFDL<\/a>], <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File%3AHanksite.JPG\">via Wikimedia Commons<\/a><\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2291\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2291\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1754\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1754\"><div tabindex=\"-1\"><p>Large metallic mineral deposit that forms near magma bodies like plutons. Commonly contains copper, lead, zinc, molybdenum, and gold.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_967\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_967\"><div tabindex=\"-1\"><p>By Hermann Luyken (Own work) [<a href=\"http:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/deed.en\">CC0<\/a>], <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File%3A2012.10.02.111543_Bonneville_Salt_Flats_Utah.jpg\">via Wikimedia Commons<\/a><\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1659\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1659\"><div tabindex=\"-1\"><p>Planar flow of water over land surfaces.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1010\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1010\"><div tabindex=\"-1\"><p>Components of magma which are dissolved until it reaches the surface, where they expand. Examples include water and carbon dioxide. Volatiles also cause flux melting in the mantle, causing volcanism.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2441\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2441\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2423\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2423\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_976\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_976\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2435\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2435\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2403\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2403\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_972\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_972\"><div tabindex=\"-1\"><figure id=\"attachment_4617\" aria-describedby=\"caption-attachment-4617\" style=\"width: 768px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Latrobe_gold_nugget_Natural_History_Museum.jpg\"><img class=\"wp-image-929 size-full\" title=\"&quot;I,\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/02\/Latrobe_gold_nugget_Natural_History_Museum.jpg\" alt=\"The nugget has cube shapes.\" width=\"768\" height=\"1024\"><\/a><figcaption id=\"caption-attachment-4617\" class=\"wp-caption-text\">The Latrobe Gold Nugget, as seen on display in the London Natural History Museum, is 717 grams and displays the rare cubic form of native gold. Most gold, even larger nuggets, grow in confined spaces where the euhedral nature of the mineral is not seen.<\/figcaption><\/figure>\n<h1>16 Energy and Mineral Resources<\/h1>\n<p><b>KEY CONCEPTS<\/b><\/p>\n<ul>\n<li>Describe how a\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a>\u00a0resource is different from a\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>\u00a0resource.<\/li>\n<li>Compare the pros and cons of extracting and using fossil fuels and conventional and unconventional petroleum sources.<\/li>\n<li>Describe how metallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are formed\u00a0and extracted.<\/li>\n<li>Understand how society uses\u00a0nonmetallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0resources.<\/li>\n<\/ul>\n<figure id=\"attachment_4618\" aria-describedby=\"caption-attachment-4618\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.0_Stone-Tool.jpg\"><img class=\"wp-image-930 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.0_Stone-Tool-300x225.jpg\" alt=\"The rock has a smooth side and a sharp side.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4618\" class=\"wp-caption-text\">A Mode 1 Oldowan tool used for chopping<\/figcaption><\/figure>\n<p>This text has previously discussed geology\u2019s pioneers, such as scientists James Hutton and Charles Lyell, but the first real \u201cgeologists\u201d were the hominids who picked up stones and began the stone age. Maybe stones were first used as curiosity pieces, maybe as weapons, but ultimately, they were used as tools. This was the Paleolithic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">Period<\/a>, the beginning of geologic study, and it dates back 2.6 million years to east Africa.<\/p>\n<p>In modern times, geologic knowledge is important for locating economically valuable materials for society\u2019s use. In fact, all things we use come from only three sources: they are farmed, hunted or fished, or mined. At the turn of the twentieth century, speculation was rampant that food supplies would not keep pace with world demand, suggesting the need to develop artificial fertilizers. Sources of fertilizer ingredients are: nitrogen is processed from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a>, using the Haber process for the manufacture of ammonia from atmospheric nitrogen and hydrogen; potassium comes from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1744\">hydrosphere<\/a>, such as lakes or ocean evaporation; and phosphorus is mined from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1668\">lithosphere<\/a>, such as minerals like apatite from phosphorite rock, which is found in Florida, North Carolina, Idaho, Utah, and around the world. \u00a0Thus, without mining and processing of natural materials, modern civilization would not exist. Indeed, geologists are essential in this process.<\/p>\n<h2><strong>16.1 Mining<\/strong><\/h2>\n<figure id=\"attachment_4619\" aria-describedby=\"caption-attachment-4619\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Simplified_world_mining_map_1.png\"><img class=\"wp-image-931 size-large\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Simplified_world_mining_map_1-1024x383.png\" alt=\"The map shows many different materials that are mined across the world.\" width=\"1024\" height=\"383\"><\/a><figcaption id=\"caption-attachment-4619\" class=\"wp-caption-text\">Map of world mining areas.<\/figcaption><\/figure>\n<p><strong>Mining<\/strong>\u00a0is defined as extracting valuable materials from the Earth for society\u2019s use. Usually, these include solid materials such as gold, iron,\u00a0coal, diamond, sand, and gravel, but materials can also include fluid resources such as\u00a0oil\u00a0and\u00a0natural gas. Modern\u00a0mining\u00a0has a long relationship with modern society. The oldest mine dates back 40,000 years to the Lion Cavern in Swaziland where there is evidence of\u00a0concentrated\u00a0digging\u00a0 into the Earth for hematite, an important iron ore used as red dye. Resources extracted by\u00a0mining\u00a0are generally considered to be\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>.<\/p>\n<h3><b>16.1.1. Renewable vs. nonrenewable resources<\/b><\/h3>\n<p>Resources generally come in two major categories:\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">Renewable<\/a> resources can be reused over and over or their availability replicated over a short human life span; <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources cannot.<\/p>\n<figure id=\"attachment_4621\" aria-describedby=\"caption-attachment-4621\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.1_Hoover_Dam_Colorado_River.jpg\"><img class=\"wp-image-932 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1_Hoover_Dam_Colorado_River-300x200.jpg\" alt=\"The dam has a large lake behind it\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4621\" class=\"wp-caption-text\">Hoover Dam provides hydroelectric energy and stores water for southern Nevada.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">Renewable<\/a><\/strong><strong>\u00a0resources<\/strong> are materials present in our environment that can be exploited and replenished. Some common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> energy sources are linked with green energy sources because they are associated with relatively small or easily remediated environmental impact. For example, solar energy comes from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1250\">fusion<\/a> within the Sun, which radiates electromagnetic energy. This energy reaches the Earth constantly and consistently and should continue to do so for about five billion more years. Wind energy, also related to solar energy, is maybe the oldest <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> energy and is used to sail ships and power windmills. Both solar and wind-generated energy are variable on Earth\u2019s surface. These limitations are offset because we can use energy storing devices, such as batteries or electricity exchanges between producing sites. The Earth\u2019s heat, known as geothermal energy, can be viable anywhere that geologists drill deeply enough. In practice, geothermal energy is more useful where heat flow is great, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> zones or regions with a thinner <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1658\">crust<\/a>. Hydroelectric dams provide energy by allowing water to fall through the dam under gravity, which activates turbines that produce the energy. Ocean tides are also a reliable energy source. All of these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> resources provide energy that powers society. Other <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> resources are plant and animal matter, which are used for food, clothing, and other necessities, but are being researched as possible energy sources.<\/p>\n<figure id=\"attachment_4622\" aria-describedby=\"caption-attachment-4622\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Rough_diamond.jpg\"><img class=\"wp-image-933 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Rough_diamond-300x226.jpg\" alt=\"The diamond is clear and pyramidal.\" width=\"300\" height=\"226\"><\/a><figcaption id=\"caption-attachment-4622\" class=\"wp-caption-text\">Natural, octahedral shape of diamond.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">Nonrenewable<\/a><\/strong><strong>\u00a0resources<\/strong> cannot be replenished at a sustainable rate. They are finite within human time frames. Many <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources come from planetary, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1654\">tectonic<\/a>, or long-term biologic processes and include materials such as gold, lead, copper, diamonds, marble, sand, natural gas, oil, and coal. Most <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources include specific concentrated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> listed on the periodic table; some are compounds of those <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. For example, if society needs iron (Fe) sources, then an exploration geologist will search for iron-rich deposits that can be economically extracted. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">Nonrenewable<\/a> resources may be abandoned when other materials become cheaper or serve a better purpose. For example, coal is abundantly available in England and other nations, but because oil and natural gas are available at a lower cost and lower environmental impact, coal use has decreased. Economic competition among <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> resources is shifting use away from coal in many developed countries.<\/p>\n<h3><b>16.1.2. Ore<\/b><\/h3>\n<figure id=\"attachment_4623\" aria-describedby=\"caption-attachment-4623\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/MichiganBIF.jpg\"><img class=\"wp-image-934 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MichiganBIF-300x206.jpg\" alt=\"The rock shows red and brown layering.\" width=\"300\" height=\"206\"><\/a><figcaption id=\"caption-attachment-4623\" class=\"wp-caption-text\">Banded-iron formations are an important ore of iron (Fe).<\/figcaption><\/figure>\n<p>Earth\u2019s materials include the\u00a0periodic table <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. However, it is rare that\u00a0these <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> are concentrated\u00a0to the point where it is profitable to extract and process the material into usable products. Any place where a valuable material is\u00a0concentrated\u00a0is a geologic and geochemical\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_765\">anomaly<\/a>. A body of material from which one or more valuable substances can be\u00a0mined\u00a0at a profit, is called an\u00a0<strong>ore<\/strong>\u00a0deposit. Typically, the term\u00a0ore\u00a0is used for only metal-bearing\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, but it can be applied to valuable <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>\u00a0resource concentrations such as fossil fuels, building stones, and other nonmetal deposits, even\u00a0groundwater. If a metal-bearing resource is not profitable to mine, it is referred to as a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> deposit. The term <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1738\">natural resource<\/a><\/strong> is more common than\u00a0the term ore\u00a0for non-metal-bearing materials.<\/p>\n<figure id=\"attachment_4624\" aria-describedby=\"caption-attachment-4624\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16-Reserve-vs-Resource.jpg\"><img class=\"wp-image-935 size-medium\" style=\"font-weight: bold;background-color: transparent;text-align: inherit\" title=\"Source: Chris Johnson\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16-Reserve-vs-Resource-300x233.jpg\" alt=\"Diagram shows the small box of &quot;reserves&quot; within a larger box of &quot;resources&quot;. There is also an &quot;inferred resources&quot; box that is slightly larger than &quot;proven reserves&quot; box and an &quot;undiscovered resources&quot; box slightly larger than the resources box.\" width=\"300\" height=\"233\"><\/a><figcaption id=\"caption-attachment-4624\" class=\"wp-caption-text\">Diagram illustrating the relative abundance of proven reserves, inferred reserves, resources, and undiscovered resources. (Source: Chris Johnson)<\/figcaption><\/figure>\n<p><span style=\"font-weight: 400\">It is implicit that the technology to mine is available, economic conditions are suitable, and political, social and environmental considerations are satisfied in order to classify a\u00a0 <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1738\">natural resource<\/a> deposit as ore. \u00a0Depending on the substance, it can be concentrated in a narrow vein or distributed over a large area as a low-concentration ore. Some materials are mined directly from bodies of water (e.g. sylvite for potassium; water through desalination) and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a> (e.g. nitrogen for fertilizers). \u00a0These differences lead to various methods of mining, and differences in terminology depending on the certainty. <strong>Ore m<\/strong><\/span><b>ineral resource<\/b><span style=\"font-weight: 400\"> is used for an indication of ore that is potentially extractable, and the term <strong>ore\u00a0<\/strong><\/span><b><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> reserve<\/b><span style=\"font-weight: 400\"> is used for a well defined (proven), profitable amount of extractable ore.<\/span><\/p>\n<figure id=\"attachment_4625\" aria-describedby=\"caption-attachment-4625\" style=\"width: 1024px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/McKelveyDiagram.jpg\"><img class=\"wp-image-936 size-large\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/McKelveyDiagram-1024x596.jpg\" alt=\"The chart shows reserves vs. resources\" width=\"1024\" height=\"596\"><\/a><figcaption id=\"caption-attachment-4625\" class=\"wp-caption-text\">McKelvey diagram showing different definitions for different degrees of concentration and understanding of mineral deposits.<\/figcaption><\/figure>\n<h3><b>16.1.3. Mining Techniques<\/b><\/h3>\n<p>The mining style is determined by technology, social license, and economics. It is in the best interest of the company extracting the resources to do so in a cost-effective way. Fluid resources, such as\u00a0oil\u00a0and gas, are extracted by drilling wells and pumping. Over the years, drilling has evolved into a complex discipline in which directional drilling can produce multiple bifurcations and curves originating from a single drill collar at the surface. Using geophysical tools like\u00a0seismic\u00a0imaging, geologists can pinpoint resources and extract efficiently.<\/p>\n<p>Solid resources are extracted by two\u00a0principal methods of which there are many variants.\u00a0<strong>Surface mining<\/strong>\u00a0is used to remove material from the outermost part\u00a0of the Earth.\u00a0<strong>Open pit<\/strong>\u00a0<strong>mining<\/strong>\u00a0is used to target shallow, broadly disseminated resources.<\/p>\n<figure id=\"attachment_4626\" aria-describedby=\"caption-attachment-4626\" style=\"width: 352px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Bingham_Canyon_mine_2016.jpg\"><img class=\"wp-image-4626\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bingham_Canyon_mine_2016-1.jpg\" alt=\"The image is a large hole in a mountainside.\" width=\"352\" height=\"212\"><\/a><figcaption id=\"caption-attachment-4626\" class=\"wp-caption-text\">Bingham Canyon Mine, Utah. This open pit mine is the largest man-made removal of rock in the world.<\/figcaption><\/figure>\n<p>Open pit mining requires careful study of the ore body through surface mapping and drilling exploratory cores. The pit is progressively deepened through additional mining cuts to extract the ore. Typically, the pit\u2019s walls are as steep as can be safely managed. Once the pit is deepened, widening the top is very expensive. A steep wall is thus an engineering balance between efficient and profitable mining (from the company's point of view) and mass wasting (angle of repose from a safety p0int of view) so that there is less waste to remove. The waste is called non-valuable rock or overburden and moving it is costly. Occasionally, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_246\">landslides<\/a> do occur, such as the very large <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_246\">landslide<\/a> in the Kennecott Bingham Canyon mine, Utah, in 2013. These events are costly and dangerous. The job of engineering geologists is to carefully monitor the mine; when company management heeds their warnings, there is ample time and action to avoid or prepare for any slide.<\/p>\n<figure id=\"attachment_4627\" aria-describedby=\"caption-attachment-4627\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Coal_mine_Wyoming.jpg\"><img class=\"size-medium wp-image-938\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Coal_mine_Wyoming-300x200.jpg\" alt=\"A large machine is removing coal.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4627\" class=\"wp-caption-text\">A surface coal mine in Wyoming.<\/figcaption><\/figure>\n<p><strong>Strip mining<\/strong>\u00a0and\u00a0<strong>mountaintop mining<\/strong>\u00a0are\u00a0surface mining\u00a0techniques that are used to mine resources that cover large areas, especially layered resources, such as coal. In this method, an entire mountaintop or rock layer is removed to access the\u00a0ore\u00a0below. Surface mining\u2019s\u00a0environmental impacts are usually much greater due to the large surface footprint that\u2019s disturbed.<\/p>\n<figure id=\"attachment_4628\" aria-describedby=\"caption-attachment-4628\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/UndergroundOilShaleEstonia.jpg\"><img class=\"size-medium wp-image-939\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/UndergroundOilShaleEstonia-300x193.jpg\" alt=\"A large truck is loading material underground.\" width=\"300\" height=\"193\"><\/a><figcaption id=\"caption-attachment-4628\" class=\"wp-caption-text\">Underground mining in Estonia of Oil Shale.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p><strong>Underground mining<\/strong>\u00a0is a method often used to mine higher-grade, more localized, or very\u00a0concentrated\u00a0resources. For one example, geologists mine some\u00a0underground ore\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0by introducing chemical agents, which dissolve\u00a0the target\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>.\u00a0Then, they bring the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1783\">solution<\/a> to the surface where\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> extracts the material. But more often, a\u00a0mining\u00a0shaft tunnel or a large network of these shafts and tunnels is dug to access the material. The decision to mine underground or from Earth\u2019s surface is dictated by\u00a0the ore\u00a0deposit\u2019s concentration, depth, geometry, land-use policies, economics, surrounding rock strength, and physical access to the\u00a0ore. For example, to use surface mining techniques for deeper deposits might require removing too much material, or the necessary method may be too dangerous or impractical, or removing the entire overburden may be too expensive, or the\u00a0mining\u00a0footprint would be too large. These factors may prevent geologists from surface mining\u00a0materials and cause a project to be\u00a0mined\u00a0underground. The mining method\u00a0and its feasibility depends on the commodity\u2019s price and the cost of the technology needed to remove it and deliver it to market.\u00a0Thus,\u00a0mines\u00a0and the towns that support them come and go as the commodity price varies.\u00a0And, conversely, technological advances and market demands may reopen\u00a0mines\u00a0and revive ghost towns.<\/p>\n<h3><b>16.1.4. Concentrating and Refining<\/b><\/h3>\n<figure id=\"attachment_4629\" aria-describedby=\"caption-attachment-4629\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.1_phosphate_smelting_furnace.jpg\"><img class=\"wp-image-940 size-medium\" title=\"&quot;Alfred\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1_phosphate_smelting_furnace-300x233.jpg\" alt=\"A man is operating a large machine that looks like a blast furnace.\" width=\"300\" height=\"233\"><\/a><figcaption id=\"caption-attachment-4629\" class=\"wp-caption-text\">A phosphate smelting operation in Alabama, 1942.<\/figcaption><\/figure>\n<p>All\u00a0ore\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0occur mixed with less desirable components called\u00a0<strong>gangue<\/strong>. The process of physically separating\u00a0gangue\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0from\u00a0ore bearing\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0is called\u00a0<strong>concentrating<\/strong>. Separating a desired\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>\u00a0from a host\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0by chemical means, including heating, is called\u00a0<strong>smelting<\/strong>. \u00a0Finally, taking a metal such as copper and removing other trace metals such as gold or silver is done through the <strong>refining<\/strong> process. Typically, <strong>refining<\/strong> is done one of three ways: 1. Materials can either be mechanically separated and processed based on the ore\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u2019s unique physical properties, such as recovering placer\u00a0gold based on its high density. 2. Materials can be heated to chemically separate desired components, such as refining\u00a0crude\u00a0oil\u00a0into\u00a0gasoline. 3. Materials can be smelted, in which controlled chemical reactions unbind metals from the\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0they are contained in, such as when copper is taken out of chalcopyrite (CuFeS<sub>2<\/sub>).\u00a0Mining,\u00a0concentrating,\u00a0smelting,\u00a0and\u00a0refining\u00a0processes require enormous energy. Continual advances in metallurgy- and\u00a0mining-practice strive to develop ever more energy efficient and environmentally benign processes and practices.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-107\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-107\" class=\"h5p-iframe\" data-content-id=\"107\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"16.1 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_4901\" aria-describedby=\"caption-attachment-4901\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/16.1-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-941\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-4901\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 16.1 via this QR Code.<\/figcaption><\/figure>\n<h2><strong>16.2. Fossil Fuels<\/strong><\/h2>\n<figure id=\"attachment_4630\" aria-describedby=\"caption-attachment-4630\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.2_Castle_Gate_Power_Plant_Utah_2007.jpg\"><img class=\"wp-image-942 size-medium\" title=\"&quot;<a\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.2_Castle_Gate_Power_Plant_Utah_2007-300x188.jpg\" alt=\"The power plant has smoke coming from it\" width=\"300\" height=\"188\"><\/a><figcaption id=\"caption-attachment-4630\" class=\"wp-caption-text\">Coal power plant in Helper, Utah.<\/figcaption><\/figure>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">Fossils<\/a><\/strong><strong>\u00a0fuels<\/strong> are extractable sources of stored energy that were created by ancient ecosystems. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1738\">natural resources<\/a> that typically fall under this category are coal, oil, petroleum, and natural gas. These resources were originally formed via photosynthesis by living organisms such as plants, phytoplankton, algae, and cyanobacteria. This energy is actually <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossil<\/a> solar energy, since the sun\u2019s ancient energy was converted by ancient organisms into tissues that preserved the chemical energy within the fossil fuel. Of course, as the energy is used, just like photosynthetic respiration that occurs today, carbon enters the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a> as CO<sub>2<\/sub>, causing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_757\">climate<\/a> consequences (see <a href=\"https:\/\/opengeology.org\/textbook\/15-global-climate-change\/\">Chapter 15<\/a>).\u00a0Today humanity uses fossil fuels\u00a0for most of the world\u2019s energy.<\/p>\n<figure id=\"attachment_4631\" aria-describedby=\"caption-attachment-4631\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Coral_Outcrop_Flynn_Reef.jpg\"><img class=\"wp-image-4631 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Coral_Outcrop_Flynn_Reef-2.jpg\" alt=\"The reef has many intricacies.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4631\" class=\"wp-caption-text\">Modern coral reefs and other highly-productive shallow marine environments are thought to be the sources of most petroleum resources.<\/figcaption><\/figure>\n<p>Converting solar energy by living organisms into hydrocarbon fossil fuels is a complex process. As organisms die, they decompose slowly, usually due to being buried rapidly, and the chemical energy stored within the organisms\u2019 tissues is buried within surrounding geologic materials. All fossil\u00a0fuels contain carbon that was produced in an ancient environment. In environments rich with organic matter such as swamps, coral reefs, and planktonic blooms, there is a higher potential for fossil fuels to accumulate. Indeed, there is some evidence that over geologic time, organic hydrocarbon fossil fuel material was highly produced globally. Lack of oxygen and moderate temperatures in the environment seem to help preserve these organic substances. Also, the heat and pressure applied to organic material after it is buried contribute to transforming it into higher quality materials, such as brown coal to anthracite and oil to gas. Heat and pressure can also cause mobile materials to migrate to conditions suitable for extraction.<\/p>\n<h3><b>16.2.1. Fossil Fuels<\/b><\/h3>\n<h4><span style=\"font-weight: 400\">OIL AND GAS<\/span><\/h4>\n<figure id=\"attachment_4632\" aria-describedby=\"caption-attachment-4632\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Oil_Reserves.png\"><img class=\"wp-image-944 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Oil_Reserves-300x136.png\" alt=\"Darker countries are higher in oil\" width=\"300\" height=\"136\"><\/a><figcaption id=\"caption-attachment-4632\" class=\"wp-caption-text\">World Oil Reserves in 2013. Scale in billions of barrels.<\/figcaption><\/figure>\n<p><strong>P<\/strong>etroleum is principally derived from organic-rich shallow\u00a0marine\u00a0sedimentary deposits where the remains of micro-organisms like plankton accumulated in fine grained <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>. Petroleum\u2019s liquid component is called\u00a0<strong>oil,<\/strong>\u00a0and its gas component is called\u00a0<strong>natural gas<\/strong>, which is mostly made up of methane (CH<sub>4<\/sub>). As rocks such as shale, mudstone, or limestone lithify, increasing pressure and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1767\">temperature<\/a> cause the oil and gas to be squeezed out and migrate from the <strong>source rock<\/strong> to a different rock unit higher in the rock column. Similar to the discussion of good\u00a0aquifers\u00a0in\u00a0<a href=\"https:\/\/opengeology.org\/textbook\/11-water\/\">Chapter 11<\/a>, if that rock is a sandstone, limestone, or other porous and permeable rock, and involved in a suitable stratigraphic or structural trapping process, then that rock can act as an<strong>\u00a0<\/strong>oil\u00a0and gas<strong> reservoir<\/strong>.<\/p>\n<figure id=\"attachment_4633\" aria-describedby=\"caption-attachment-4633\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Structural_Trap_Anticlinal.svg_.png\"><img class=\"wp-image-945 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Structural_Trap_Anticlinal.svg_-300x194.png\" alt=\"The rock layers are folded, and the petroleum is pooling toward the top of the fold.\" width=\"300\" height=\"194\"><\/a><figcaption id=\"caption-attachment-4633\" class=\"wp-caption-text\">A structural or anticline trap. The red on the image represents pooling petroleum. The green layer would be a permeable rock, and the yellow would be a reservoir rock.<\/figcaption><\/figure>\n<p>A\u00a0<strong>trap<\/strong> is a combination of a subsurface geologic structure, a porous and permeable rock, and an impervious layer that helps block oil and gas from moving further, which concentrates it for humans to extract later. A trap develops due to many different geologic situations. Examples include an <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_504\">anticline<\/a> or domal structure, an impermeable salt <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_507\">dome<\/a>, or a fault bounded stratigraphic block, which is porous rock next to nonporous rock. The different traps have one thing in common: they pool fluid fossil fuels into a configuration in which extracting it is more likely to be profitable. Oil or gas in strata outside of a trap renders it less viable to extract.<\/p>\n<figure id=\"attachment_4634\" aria-describedby=\"caption-attachment-4634\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/TransgressionRegression.png\"><img class=\"wp-image-946 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/TransgressionRegression-300x199.png\" alt=\"Onlap is sediments moving toward the land. Offlap is moving away.\" width=\"300\" height=\"199\"><\/a><figcaption id=\"caption-attachment-4634\" class=\"wp-caption-text\">The rising sea levels of transgressions create onlapping sediments, regressions create offlapping.<\/figcaption><\/figure>\n<p><strong>Sequence stratigraphy<\/strong> is a branch of geology that studies sedimentary facies both horizontally and vertically and is devoted to understanding how sea level changes create organic-rich shallow marine muds, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonates<\/a>, and sands in areas that are close to each other. For example, shoreline environments may have beaches, lagoons, reefs, nearshore and offshore deposits, all next to each other. Beach sand, lagoonal and nearshore muds, and coral reef layers accumulate into <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> that include sandstones\u2014good reservoir rocks\u2014 next to mudstones, next to limestones, both of which are potential source rocks. As sea level either rises or falls, the shoreline\u2019s location changes, and the sand, mud, and reef locations shift with it (see the figure). This places oil and gas producing rocks, such as mudstones and limestones next to oil and gas reservoirs, such as sandstones and some limestones. Understanding how the lithology and the facies\/stratigraphic relationships interplay is very important in finding new petroleum resources. Using sequence stratigraphy as a model allows geologists to predict favorable locations of the source rock and reservoir.<\/p>\n<h4><span style=\"font-weight: 400\">Tar Sands<\/span><\/h4>\n<figure id=\"attachment_4635\" aria-describedby=\"caption-attachment-4635\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Tar_Sandstone_California.jpg\"><img class=\"wp-image-947 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Tar_Sandstone_California-300x286.jpg\" alt=\"The sandstone is black with tar.\" width=\"300\" height=\"286\"><\/a><figcaption id=\"caption-attachment-4635\" class=\"wp-caption-text\">Tar sandstone from the Miocene Monterrey Formation of California.<\/figcaption><\/figure>\n<p><strong>Conventional<\/strong>\u00a0oil\u00a0and gas, which is pumped from a\u00a0reservoir, is not the only way to obtain hydrocarbons. There are a few fuel sources known as <strong>unconventional<\/strong>\u00a0petroleum\u00a0sources. However, they are becoming more important as conventional sources become scarce.\u00a0<strong>Tar sands<\/strong>, or oil sands, are sandstones that contain petroleum products that are highly viscous, like tar, and thus cannot be drilled and pumped out of the ground readily like conventional oil. This unconventional fossil fuel is <strong>bitumen<\/strong>, which can be pumped as a fluid only at very low recovery rates and only when heated or mixed with solvents. So, using steam and solvent injections or directly mining tar sands to process later are ways to extract the tar from the sands. Alberta, Canada is known to have the largest tar sand reserves in the world. Note: as with ores, an energy resource becomes uneconomic if the total extraction and processing costs exceed the extracted material\u2019s sales revenue. Environmental costs may also contribute to a resource becoming uneconomic.<\/p>\n<h4><span style=\"font-weight: 400\">Oil Shale<\/span><\/h4>\n<figure id=\"attachment_4636\" aria-describedby=\"caption-attachment-4636\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Production_of_oil_shale.png\"><img class=\"wp-image-948 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Production_of_oil_shale-300x195.png\" alt=\"Oil shale has dramatically increased starting around 1945.\" width=\"300\" height=\"195\"><\/a><figcaption id=\"caption-attachment-4636\" class=\"wp-caption-text\">Global production of Oil Shale, 1880-2010.<\/figcaption><\/figure>\n<p><strong>Oil shale<\/strong>, or\u00a0tight oil, is a fine-grained\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1761\">sedimentary rock<\/a>\u00a0that has significant petroleum\u00a0or\u00a0natural gas quantities locked tightly in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediment<\/a>.\u00a0Shale\u00a0has high\u00a0porosity\u00a0but very low permeability and is a common fossil fuel source rock. To extract the\u00a0oil directly from the shale, the material has to be\u00a0mined\u00a0and heated, which, like with tar sands, is expensive and typically has a negative environmental impact.<\/p>\n<h4><span style=\"font-weight: 400\">Fracking<\/span><\/h4>\n<figure id=\"attachment_4637\" aria-describedby=\"caption-attachment-4637\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/HydroFrac2.svg_.png\"><img class=\"wp-image-949 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/HydroFrac2.svg_-300x175.png\" alt=\"The image shows fracking fluids cracking the rock, allowing methane to escape.\" width=\"300\" height=\"175\"><\/a><figcaption id=\"caption-attachment-4637\" class=\"wp-caption-text\">Schematic diagram of fracking.<\/figcaption><\/figure>\n<p>Another process used to extract the\u00a0oil\u00a0and gas from\u00a0shale\u00a0and other unconventional tight resources is called\u00a0<strong>hydraulic fracturing<\/strong>, better known as\u00a0<strong>fracking<\/strong>. In this method, high-pressure water, sand grains, and added chemicals are injected and pumped underground. Under high pressure, this creates and holds open\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_986\">fractures<\/a>\u00a0in the rocks, which help release the hard-to-access mostly\u00a0natural gas fluids. Fracking is more useful in tighter\u00a0sediments, especially\u00a0shale, which has a high\u00a0porosity\u00a0to store the hydrocarbons but low permeability to allow transmission of the hydrocarbons.\u00a0Fracking\u00a0has become controversial because its methods contaminate groundwater\u00a0and\u00a0induce seismic activity. This has created much controversy between public concerns, political concerns, and energy value.<\/p>\n<h3><b>16.2.2. Coal<\/b><\/h3>\n<figure id=\"attachment_4638\" aria-describedby=\"caption-attachment-4638\" style=\"width: 240px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Coal_Rank_USGS.png\"><img class=\"wp-image-950 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Coal_Rank_USGS-240x300.png\" alt=\"The chart shows many different coal rankings\" width=\"240\" height=\"300\"><\/a><figcaption id=\"caption-attachment-4638\" class=\"wp-caption-text\">USGS diagram of different coal rankings.<\/figcaption><\/figure>\n<p><strong>Coal<\/strong>\u00a0comes from fossilized swamps, though some older\u00a0coal\u00a0deposits that predate\u00a0terrestrial\u00a0plants are presumed to come from algal buildups. Coal is chiefly carbon, hydrogen, nitrogen, sulfur, and oxygen, with minor amounts of other\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>. As plant material is incorporated into\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a>, heat and pressure cause several changes that concentrate the fixed carbon, which is the coal\u2019s combustible portion. So, the more heat and pressure that\u00a0coal\u00a0undergoes, the greater is its carbon concentration and fuel value and the more desirable is the\u00a0coal.<\/p>\n<p>This is the general sequence of a swamp progressing through the various stages of coal formation and becoming more concentrated in carbon: Swamp =&gt; Peat =&gt; Lignite =&gt; Sub-bituminous =&gt; Bituminous =&gt; Anthracite =&gt; Graphite. As swamp materials collect on the swamp floor and are buried under accumulating materials, they first turn to peat.<\/p>\n<figure id=\"attachment_4639\" aria-describedby=\"caption-attachment-4639\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Peat_49302157252.jpg\"><img class=\"size-medium wp-image-951\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Peat_49302157252-300x225.jpg\" alt=\"A lump of peat.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4639\" class=\"wp-caption-text\">Peat (also known as turf) consists of partially decayed organic matter. The Irish have long mined peat to be burned as fuel though this practice is now discouraged for environmental reasons.<\/figcaption><\/figure>\n<p>Peat itself is an economic fuel in some locations like the British Isles and Scandinavia. As <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1760\">lithification<\/a> occurs, peat turns to lignite. With increasing heat and pressure, lignite turns to sub-bituminous coal, bituminous coal, and then, in a process like metamorphism, anthracite. Anthracite is the highest metamorphic grade and most desirable coal since it provides the highest energy output. With even more heat and pressure driving out all the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1684\">volatiles<\/a> and leaving pure carbon, anthracite can become graphite.<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_4640\" aria-describedby=\"caption-attachment-4640\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Coal_anthracite.jpg\"><img class=\"wp-image-4640 size-medium\" title=\"&quot;USGS\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Coal_anthracite-1.jpg\" alt=\"It is very black and shiny.\" width=\"300\" height=\"281\"><\/a><figcaption id=\"caption-attachment-4640\" class=\"wp-caption-text\">Anthracite coal, the highest grade of coal.<\/figcaption><\/figure>\n<p>Humans have used coal for at least 6,000 years, mainly as a fuel source. Coal resources in Wales are often cited as a primary reason for Britain\u2019s rise, and later, for the United States\u2019 rise during the Industrial Revolution. According to the US Energy Information Administration, US coal production has decreased due to competing energy sources\u2019 cheaper prices and due to society recognizing its negative environmental impacts, including increased very fine-grained particulate matter as an air pollutant, greenhouse gases, acid rain, and heavy metal pollution. Seen from this perspective, the coal industry as a source of <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1228\">fossil<\/a> energy is unlikely to revive.<\/p>\n<p>As the world transitions away from fossil fuels including coal, and manufacturing seeks strong, flexible, and lighter materials than steel including carbon fiber for many applications, current research is exploring coal as a source of this carbon.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-108\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-108\" class=\"h5p-iframe\" data-content-id=\"108\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"16.2 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_4902\" aria-describedby=\"caption-attachment-4902\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/16.2-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-953\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.2-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-4902\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 16.2 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">16.3 Mineral Resources<\/span><\/h2>\n<figure id=\"attachment_4641\" aria-describedby=\"caption-attachment-4641\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Mother_Lode_Gold_OreHarvard_mine_quartz-gold_vein.jpg\"><img class=\"wp-image-954 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Mother_Lode_Gold_OreHarvard_mine_quartz-gold_vein-300x209.jpg\" alt=\"The yellow gold is inside white quartz.\" width=\"300\" height=\"209\"><\/a><figcaption id=\"caption-attachment-4641\" class=\"wp-caption-text\">Gold-bearing quartz vein from California.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Mineral<\/a>\u00a0resources, while principally\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>, are generally placed\u00a0in two main categories:\u00a0<strong>metallic<\/strong>, which contain metals, and\u00a0<strong>nonmetallic<\/strong>, which contain other useful materials. Most\u00a0mining\u00a0has been traditionally focused on\u00a0extracting metallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. Human society has advanced significantly because we\u2019ve developed the\u00a0knowledge and technologies to yield metal from the Earth. This knowledge has allowed humans to build the machines, buildings, and monetary systems that dominate our world today. Locating and recovering these metals has been a key facet of geologic study since its inception. Every\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a>\u00a0across the periodic table has specific applications in human civilization.\u00a0Metallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0mining\u00a0is the source of many of these\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>.<\/p>\n<h3><b>16.3.1. Types of Metallic Mineral Deposits<\/b><\/h3>\n<p>The various ways in which <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0and their associated\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a>\u00a0concentrate to form\u00a0ore\u00a0deposits are too complex and numerous to fully review in this text. However, entire careers are built around them.\u00a0In the following section, we describe some of the more common deposit types along with their associated elemental concentrations and world class occurrences.<\/p>\n<h4><span style=\"font-weight: 400\">Magmatic Processes<\/span><\/h4>\n<figure id=\"attachment_4642\" aria-describedby=\"caption-attachment-4642\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/LayeredIntrusionChromitite_Bushveld_South_Africa.jpg\"><img class=\"wp-image-955 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/LayeredIntrusionChromitite_Bushveld_South_Africa-300x211.jpg\" alt=\"The rock has several layers, with the dark layers being the ones with value.\" width=\"300\" height=\"211\"><\/a><figcaption id=\"caption-attachment-4642\" class=\"wp-caption-text\">Layered intrusion of dark chromium-bearing minerals, Bushveld Complex, South Africa<\/figcaption><\/figure>\n<p>When a magmatic body crystallizes and differentiates (see Chapter 4), it can cause certain <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> to concentrate. <strong>Layered<\/strong>\u00a0<strong>intrusions<\/strong>, typically <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">ultramafic<\/a> to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">mafic<\/a>, can host deposits that contain copper, nickel, platinum, palladium, rhodium, and chromium. The Stillwater Complex in Montana is an example of economic quantities of layered <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1008\">mafic<\/a> intrusion. Associated deposit types can contain chromium or titanium-vanadium. The largest magmatic deposits in the world are the chromite deposits in the Bushveld <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">Igneous<\/a> Complex in South Africa. These rocks have an areal extent larger than the state of Utah. The chromite occurs in layers, which resemble sedimentary layers, except these layers occur within a crystallizing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_232\">magma chamber<\/a>.<\/p>\n<figure id=\"attachment_4909\" aria-describedby=\"caption-attachment-4909\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/Elbai\u0308te_et_mica_Bre\u0301sil_1.jpg\"><img class=\"size-medium wp-image-4909\" src=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/Elbai\u0308te_et_mica_Bre\u0301sil_1-300x199.jpg#fixme\" alt=\"The rock is mostly green and purple\" width=\"300\" height=\"199\"><\/a><figcaption id=\"caption-attachment-4909\" class=\"wp-caption-text\">This pegmatite contains lithium-rich green elbaite (a tourmaline) and purple lepidolite (a mica).<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<p>Water and other\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1684\">volatiles<\/a>\u00a0that are not incorporated into\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0crystals when a\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>\u00a0crystallizes can become\u00a0concentrated\u00a0around the crystallizing\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>\u2019s margins. Ions in these hot fluids are very mobile and can form exceptionally large crystals.\u00a0Once crystallized, these large crystal masses are then called\u00a0<strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_996\">pegmatites<\/a><\/strong>. They form from <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> fluids that are expelled from the solidifying <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> when nearly the entire <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> body has crystallized. In addition to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that are predominant in the main <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> mass, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_967\">quartz<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_966\">mica<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_996\">pegmatite<\/a> bodies may also contain very large crystals of unusual <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> that contain rare <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> like beryllium, lithium, tantalum, niobium, and tin, as well as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> like gold. Such <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_996\">pegmatites<\/a> are ores of these metals.<\/p>\n<figure id=\"attachment_4643\" aria-describedby=\"caption-attachment-4643\" style=\"width: 298px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/KimberlitePipe.jpg\"><img class=\"wp-image-956 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/KimberlitePipe-298x300.jpg\" alt=\"The pipe is deep and narrow.\" width=\"298\" height=\"300\"><\/a><figcaption id=\"caption-attachment-4643\" class=\"wp-caption-text\">Schematic diagram of a kimberlite pipe.<\/figcaption><\/figure>\n<p>An unusual magmatic process is a\u00a0<strong>kimberlite<\/strong> pipe, which is a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_228\">volcanic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_233\">conduit<\/a> that transports <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">ultramafic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> from within the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1664\">mantle<\/a> to the surface. Diamonds, which are formed at great temperatures and pressures of depth, are transported by a Kimberlite pipe to locations where they can be mined. The process that created these kimberlite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">ultramafic<\/a> rocks is no longer common on Earth. Most known deposits are from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1257\">Archean<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1242\">Eon<\/a>.<\/p>\n<h4><span style=\"font-weight: 400\">Hydrothermal Processes<\/span><\/h4>\n<figure id=\"attachment_4644\" aria-describedby=\"caption-attachment-4644\" style=\"width: 400px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Deep_sea_vent_chemistry_diagram.jpg\"><img class=\"wp-image-4644\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Deep_sea_vent_chemistry_diagram-1.jpg\" alt=\"The diagram shows water going into the ground and coming out, with many different reactions.\" width=\"400\" height=\"233\"><\/a><figcaption id=\"caption-attachment-4644\" class=\"wp-caption-text\">The complex chemistry around mid-ocean ridges.<\/figcaption><\/figure>\n<p>Fluids rising from crystallizing magmatic bodies or that are heated by the\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_222\">geothermal gradient<\/a>\u00a0cause many geochemical reactions that form various <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0deposits. The most active\u00a0hydrothermal\u00a0process today produces\u00a0<strong>volcanogenic massive sulfide<\/strong><strong>\u00a0<\/strong>(VMS) deposits, which form from black smoker hydrothermal chimney activity near <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1708\">mid-ocean ridges<\/a> all over the world. They commonly contain copper, zinc, lead, gold, and silver when found at the surface. Evidence from around 7000 BC in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">period<\/a> known as the Chalcolithic shows copper was among the earliest metals smelted by humans as means of obtaining higher temperatures were developed. The largest of these VMS deposits occur in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1270\">Precambrian<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1244\">period<\/a> rocks. The Jerome deposit in central Arizona is a good example.<\/p>\n<p>Another deposit type that draws on <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>-heated water is a\u00a0<strong>porphyry<\/strong> deposit. This is not to be confused with the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_994\">porphyritic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> texture, although the name is derived from the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_994\">porphyritic<\/a> texture that is nearly always present in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> rocks associated with a porphyry deposit. Several types of porphyry deposits exist, such as porphyry copper, porphyry molybdenum, and porphyry tin. These deposits contain low-grade disseminated ore <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> closely associated with <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1007\">intermediate<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1006\">felsic<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_991\">intrusive<\/a> rocks that are present over a very large area. Porphyry deposits are typically the largest mines on Earth. One of the largest, richest, and possibly best studied mine in the world is Utah\u2019s Kennecott Bingham Canyon Mine. It\u2019s an open pit mine, which, for over 100 years, has produced several <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">elements<\/a> including copper, gold, molybdenum, and silver. Underground <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> replacement deposits produce lead, zinc, gold, silver, and copper. In the mine\u2019s past, the open pit predominately produced copper and gold from chalcopyrite and bornite. Gold only occurs in minor quantities in the copper-bearing <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, but because the Kennecott Bingham Canyon Mine produces on such a large scale, it is one of the largest gold <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mines<\/a> in the US. In the future, this mine may produce more copper and molybdenum (molybdenite) from deeper underground mines.<\/p>\n<figure id=\"attachment_4645\" aria-describedby=\"caption-attachment-4645\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Morenci_Mine_2012.jpg\"><img class=\"wp-image-958 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Morenci_Mine_2012-300x200.jpg\" alt=\"The mine contains grey rocks, which are not enriched, and red rocks, which is where the enrichment occurs.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4645\" class=\"wp-caption-text\">The Morenci porphyry is oxidized toward its top (as seen as red rocks in the wall of the mine), creating supergene enrichment.<\/figcaption><\/figure>\n<p>Most porphyry\u00a0copper deposits owe their high metal content, and hence, their economic value to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>\u00a0processes called<strong> supergene enrichment<\/strong> which occurs when the\u00a0deposit is uplifted, eroded, and exposed to\u00a0<strong>oxidation<\/strong>. This process <b>occur<\/b>r<b>ed<\/b> millions of years after the initial <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> intrusion and hydrothermal expulsion ends. When the deposit\u2019s upper pyrite-rich portion is exposed to rain, the pyrite in the oxidizing zone creates an extremely acid condition that dissolves copper out of copper\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>,\u00a0such as chalcopyrite, and converts the chalcopyrite to iron\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxides<\/a>,\u00a0such as hematite or goethite. The copper <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are carried downward in\u00a0water until they arrive at the\u00a0groundwater\u00a0table and an environment where the primary copper\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> are converted\u00a0into secondary higher-copper content\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. Chalcopyrite (35% Cu) is converted to bornite (63% Cu), and ultimately, chalcocite (80% Cu).\u00a0Without this enriched zone, which is two to five times higher in copper content than the main deposit, most\u00a0porphyry\u00a0copper deposits would not be economic to mine.<\/p>\n<figure id=\"attachment_4646\" aria-describedby=\"caption-attachment-4646\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.3_6_cm_grossular_calcite_augite_skarn.jpg\"><img class=\"wp-image-959 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.3_6_cm_grossular_calcite_augite_skarn-300x255.jpg\" alt=\"Calcite is blue, augite green, and garnet brown\/orange in this rock.\" width=\"300\" height=\"255\"><\/a><figcaption id=\"caption-attachment-4646\" class=\"wp-caption-text\">Garnet-augite skarn from Italy.<\/figcaption><\/figure>\n<p>If\u00a0limestone\u00a0or other calcareous sedimentary rocks are near the magmatic body, then another type of\u00a0ore\u00a0deposit called a\u00a0<strong>skarn<\/strong>\u00a0deposit forms. These\u00a0metamorphic\u00a0rocks form as\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>-derived, highly saline metalliferous fluids react with\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a>\u00a0rocks to create calcium-magnesium-<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1787\">silicate<\/a>\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0like\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1790\">pyroxene<\/a>,\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1791\">amphibole<\/a>, and garnet, as well as high-grade\u00a0iron, copper, zinc\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>,\u00a0and gold. Intrusions that are genetically related to the intrusion that made the Kennecott Bingham Canyon deposit have also produced copper-gold skarns, which were\u00a0mined\u00a0by the early European settlers in Utah. When iron and\/or\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>\u00a0deposits undergo metamorphism, the\u00a0grain\u00a0size\u00a0commonly increases, which makes separating the\u00a0gangue\u00a0from the desired\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>\u00a0or\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a>\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0much easier.<\/p>\n<figure id=\"attachment_4647\" aria-describedby=\"caption-attachment-4647\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/GoldinPyrite.jpg\"><img class=\"wp-image-4647 size-medium\" title=\"&quot;<a\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/GoldinPyrite-1.jpg\" alt=\"The rock is red.\" width=\"300\" height=\"240\"><\/a><figcaption id=\"caption-attachment-4647\" class=\"wp-caption-text\">In this rock, a pyrite cube has dissolved (as seen with the negative \"corner\" impression in the rock), leaving behind small specks of gold.<\/figcaption><\/figure>\n<p><strong>Sediment-hosted disseminated gold<\/strong> deposits consist of low concentrations of microscopic gold as inclusions and disseminated atoms in pyrite crystals. These are formed via low-grade hydrothermal reactions, generally in the realm of diagenesis, that occur in certain rock types, namely muddy <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonates<\/a> and limey mudstones. This hydrothermal alteration is generally far removed from a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a> source, but can be found in rocks situated with a high <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_222\">geothermal gradient<\/a>. The Mercur deposit in Utah\u2019s Oquirrh Mountains was this type\u2019s earliest locally mined deposit. There, almost a million ounces of gold was recovered between 1890 and 1917. In the 1960s, a metallurgical process using cyanide was developed for these low-grade ore types. These deposits are also called\u00a0<strong>Carlin-type<\/strong><strong>\u00a0<\/strong>deposits\u00a0because the disseminated deposit near Carlin, Nevada, is where the new technology was first applied and where the first definitive scientific studies were conducted. Gold was introduced into these deposits by\u00a0hydrothermal\u00a0fluids that reacted with silty calcareous rocks, removing\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a>, creating additional permeability, and adding silica and gold-bearing pyrite in the\u00a0pore\u00a0space between grains. The Betze-Post\u00a0mine\u00a0and the Gold Quarry\u00a0mine\u00a0on the Carlin Trend are two of the largest disseminated gold deposits in Nevada. Similar deposits, but not as large, have been found in China, Iran, and Macedonia.<\/p>\n<h4><span style=\"font-weight: 400\">Non-magmatic Geochemical Processes <\/span><\/h4>\n<figure id=\"attachment_4648\" aria-describedby=\"caption-attachment-4648\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/16.1_UraniumMineUtah.jpg\"><img class=\"wp-image-961 size-medium\" title=\"&quot;<a\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.1_UraniumMineUtah-300x225.jpg\" alt=\"A dark shaft runs into the mountain.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4648\" class=\"wp-caption-text\">Underground uranium mine near Moab, Utah.<\/figcaption><\/figure>\n<p>Geochemical processes that occur at or near the surface without <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1750\">magma<\/a>\u2019s\u00a0aid also concentrate metals, but to a lesser degree than\u00a0hydrothermal\u00a0processes. One of the main reactions is\u00a0<strong>redox<\/strong>, short for reduction\/oxidation chemistry, which has to do with the amount of available oxygen in a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1742\">system<\/a>. Places where oxygen is plentiful, as in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a> today, are considered oxidizing environments, while oxygen-poor places are considered reducing environments. Uranium deposits are an example of where redox concentrated the metal. Uranium is soluble in oxidizing groundwater environments and precipitates as uraninite when encountering reducing conditions. Many of the deposits across the Colorado Plateau, such as in \u00a0Moab, Utah, were formed by this method.<\/p>\n<p>Redox\u00a0reactions are also responsible for creating <strong>banded iron<\/strong><strong>\u00a0<\/strong><strong>formations<\/strong><strong>\u00a0<\/strong>(BIFs),<strong>\u00a0<\/strong>which are interbedded layers of iron\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_971\">oxide<\/a>\u2014hematite and magnetite,\u00a0chert, and\u00a0shale\u00a0beds. These deposits formed early in the Earth\u2019s history as the\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1745\">atmosphere<\/a>\u00a0was becoming oxygenated. Cycles of oxygenating iron-rich waters initiated <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitation<\/a> of the\u00a0iron\u00a0beds. Because BIFs are generally\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1270\">Precambrian<\/a>\u00a0in age, happening at the event of atmospheric oxygenation, they are only found in some of the older exposed rocks in the United States, such as in Michigan\u2019s upper peninsula and northeast Minnesota.<\/p>\n<figure id=\"attachment_4649\" aria-describedby=\"caption-attachment-4649\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/MV-Type_and_clastic_sediment-hosted_lead-zinc_deposits.svg_.png\"><img class=\"wp-image-962 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/MV-Type_and_clastic_sediment-hosted_lead-zinc_deposits.svg_-300x138.png\" alt=\"The are globally distributed.\" width=\"300\" height=\"138\"><\/a><figcaption id=\"caption-attachment-4649\" class=\"wp-caption-text\">Map of Mississippi-Valley type ore deposits.<\/figcaption><\/figure>\n<p>Deep, saline, connate fluids (trapped in pore spaces) within <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_510\">sedimentary basins<\/a>\u00a0may be highly metalliferous. When expelled outward and upward as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_508\">basin<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1756\">sediments<\/a> compacted, these fluids formed lead and zinc deposits in limestone by replacing or filling open spaces, such as caves and faults, and in sandstone by filling pore spaces. The most famous are called\u00a0<strong>Mississippi Valley-type<\/strong><strong>\u00a0<\/strong>deposits. Also known as\u00a0carbonate-hosted replacement\u00a0deposits, they are large deposits of galena and sphalerite lead and zinc\u00a0ores that form from hot fluids ranging from 100\u00b0C to 200\u00b0C (212\u00b0F to 392\u00b0F). Although they are named for occurring along the Mississippi\u00a0River\u00a0Valley in the US, they are found worldwide.<\/p>\n<p><strong>Sediment-hosted copper<\/strong><strong>\u00a0<\/strong>deposits occurring in\u00a0sandstones,\u00a0shales, and marls are enormous, and their contained resources are comparable to\u00a0porphyry\u00a0copper deposits. These deposits were most likely formed diagenetically by\u00a0groundwater\u00a0fluids in highly permeable rocks. Well-known examples are the Kupferschiefer in Europe, which has an areal coverage of &gt;500,000 Km<sup>2<\/sup>, (310,685.596mi) and the Zambian Copper Belt in Africa.<\/p>\n<figure id=\"attachment_4650\" aria-describedby=\"caption-attachment-4650\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Bauxite_with_unweathered_rock_core._C_021.jpg\"><img class=\"wp-image-4650 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bauxite_with_unweathered_rock_core._C_021-1.jpg\" alt=\"The outside of the rock is tan and weathered, the inside is grey.\" width=\"300\" height=\"195\"><\/a><figcaption id=\"caption-attachment-4650\" class=\"wp-caption-text\">A sample of bauxite. Note the unweathered igneous rock in the center.<\/figcaption><\/figure>\n<p><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">Soils<\/a>\u00a0and\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0deposits that are exposed at the surface experience deep and intense\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>, which\u00a0can form surficial deposits.\u00a0<strong>Bauxite<\/strong>, an aluminum ore, is preserved in karst topography and laterites, which are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">soils<\/a> formed in wet tropical environments. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">Soils<\/a> containing aluminum concentrate <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, such as <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_968\">feldspar<\/a>, and ferromagnesian <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> and metamorphic rocks, undergo chemical weathering processes that concentrate the metals. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1009\">Ultramafic<\/a> rocks that undergo <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a> form nickel-rich <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_250\">soils<\/a>, and when the magnetite and hematite in banded iron formations undergo <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>, it forms goethite, a friable <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> that is easily mined for its iron content.<\/p>\n<h3><span style=\"font-weight: 400\">Surficial Physical Processes <\/span><\/h3>\n<figure id=\"attachment_4651\" aria-describedby=\"caption-attachment-4651\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/HeavyMineralsBeachSand.jpg\"><img class=\"wp-image-4651 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/HeavyMineralsBeachSand-1.jpg\" alt=\"The tan rock has dark streaks of minerals.\" width=\"300\" height=\"205\"><\/a><figcaption id=\"caption-attachment-4651\" class=\"wp-caption-text\">Lithified heavy mineral sand (dark layers) from a beach deposit in India.<\/figcaption><\/figure>\n<p>At the Earth\u2019s surface, mass wasting\u00a0and moving water can cause hydraulic\u00a0sorting, which forces high-density\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> to concentrate. When these\u00a0minerals\u00a0are\u00a0concentrated\u00a0in\u00a0streams,\u00a0rivers,\u00a0and beaches, they are called\u00a0<strong>placer<\/strong>\u00a0deposits, and occur in modern sands and ancient lithified rocks.\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">Native<\/a>\u00a0gold,\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_976\">native<\/a>\u00a0platinum,\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1227\">zircon<\/a>, ilmenite, rutile, magnetite, diamonds, and other gemstones can be found in\u00a0placers. Humans have mimicked this natural process to recover gold manually by gold panning and by mechanized means such as dredging.<\/p>\n<h3><b>16.3.2. Environmental Impacts of Metallic Mineral Mining<\/b><\/h3>\n<figure id=\"attachment_4652\" aria-describedby=\"caption-attachment-4652\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Rio_tinto_river_CarolStoker_NASA_Ames_Research_Center.jpg\"><img class=\"wp-image-965 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Rio_tinto_river_CarolStoker_NASA_Ames_Research_Center-300x225.jpg\" alt=\"The water in the river is bright orange.\" width=\"300\" height=\"225\"><\/a><figcaption id=\"caption-attachment-4652\" class=\"wp-caption-text\">Acid mine drainage in the Rio Tinto, Spain.<\/figcaption><\/figure>\n<p>Metallic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0mining\u2019s\u00a0primary impact comes from the\u00a0mining\u00a0itself, including disturbing the land surface, covering landscapes with tailings impoundments, and increasing\u00a0mass wasting\u00a0by accelerating\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1755\">erosion<\/a>. In addition, many metal deposits contain pyrite, an uneconomic\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfide<\/a>\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>, that when\u00a0placed on waste dumps, generates\u00a0<strong>acid rock drainage<\/strong>\u00a0(ARD)<strong>\u00a0<\/strong>during <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1754\">weathering<\/a>. In oxygenated water, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfides<\/a> such as pyrite react and undergo complex reactions to release metal ions and hydrogen ions, which lowers pH to highly acidic levels. Mining and processing of mined materials typically increase the surface area to volume ratio in the material, causing chemical reactions to occur even faster than would occur naturally. If not managed properly, these reactions lead to acidic streams and groundwater plumes that carry dissolved toxic metals. In mines where limestone is a waste rock or where <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_969\">carbonate<\/a> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a> like <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_970\">calcite<\/a> or dolomite are present, their acid neutralizing potential helps reduce acid rock drainage. Although this is a natural process too, it is very important to isolate mine dumps and tailings from oxygenated water, both to prevent the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_973\">sulfides<\/a> from dissolving and subsequently percolating the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_974\">sulfate<\/a>-rich water into waterways. Industry has taken great strides to prevent contamination in recent decades, but earlier mining projects are still causing problems with local ecosystems.<\/p>\n<h3><strong>16.3.3. Nonmetallic Mineral\u00a0Deposits<\/strong><\/h3>\n<figure id=\"attachment_4653\" aria-describedby=\"caption-attachment-4653\" style=\"width: 225px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/CarraraMarblequarry.jpg\"><img class=\"wp-image-966 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/CarraraMarblequarry-225x300.jpg\" alt=\"The image shows a hillside with blocks of marble removed.\" width=\"225\" height=\"300\"><\/a><figcaption id=\"caption-attachment-4653\" class=\"wp-caption-text\">Carrara marble quarry in Italy, source to famous sculptures like Michelangelo's David.<\/figcaption><\/figure>\n<p>While receiving much less attention, nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> resources, also known as industrial <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, are just as vital to ancient and modern society as metallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>. The most basic is building stone. Limestone, travertine, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1014\">granite<\/a>, slate, and marble are common building stones and have been quarried for centuries. Even today, building stones from slate roof tiles to <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1014\">granite<\/a> countertops are very popular. Especially pure limestone is ground up, processed, and reformed as plaster, cement, and concrete. Some nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> resources are not <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> specific; nearly any rock or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> can be used. This is generally called aggregate, which is used in concrete, roads, and foundations. Gravel is one of the more common aggregates.<\/p>\n<h4><span style=\"font-weight: 400\">Evaporites<\/span><\/h4>\n<figure id=\"attachment_4654\" aria-describedby=\"caption-attachment-4654\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Bonneville_Salt_Flats_Utah.jpg\"><img class=\"wp-image-4654 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Bonneville_Salt_Flats_Utah-1.jpg\" alt=\"The ground is white and flat for a long distance.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4654\" class=\"wp-caption-text\">Salt-covered plain known as the Bonneville Salt Flats, Utah.<\/figcaption><\/figure>\n<p><strong>Evaporite<\/strong><strong>\u00a0<\/strong>deposits\u00a0form in restricted basins where water evaporates faster than it recharges, such as the Great Salt Lake in Utah, or the Dead Sea, which borders Israel and Jordan. As the waters evaporate, soluble\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>\u00a0are\u00a0concentrated\u00a0and become supersaturated, at which point they\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1785\">precipitate<\/a>\u00a0from the now highly-saline waters. If these conditions persist for long stretches, thick rock salt, rock\u00a0gypsum,\u00a0and other\u00a0<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a>\u00a0deposits accumulate (see Chapter 5).<\/p>\n<figure id=\"attachment_4655\" aria-describedby=\"caption-attachment-4655\" style=\"width: 300px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Hanksite.jpg\"><img class=\"wp-image-968 size-medium\" title=\"&quot;By\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Hanksite-300x200.jpg\" alt=\"The mineral is hexagonal and clear.\" width=\"300\" height=\"200\"><\/a><figcaption id=\"caption-attachment-4655\" class=\"wp-caption-text\">Hanksite, Na22K(SO4)9(CO3)2Cl, one of the few minerals that is considered a carbonate and a sulfate<\/figcaption><\/figure>\n<p>Evaporite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, such as halite, are used in our food as common table salt. Salt was a vitally important food preservative and economic resource before refrigeration was developed. While still used in food, halite is now mainly mined as a chemical agent, water softener, or road de-icer. Gypsum is a common nonmetallic <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> used as a building material; it is the main component in dry wall. It is also used as a fertilizer. Other evaporites include sylvite\u2014potassium chloride, and bischofite\u2014magnesium chloride, both of which are used in agriculture, medicine, food processing, and other applications. Potash, a group of highly soluble potassium-bearing evaporite <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">minerals<\/a>, is used as a fertilizer. In hyper-arid locations, even more rare and complex evaporites, like borax, trona, ulexite, and hanksite are mined. They can be found in places such as Searles Dry Lake and Death Valley, California, and in the Green River Formation\u2019s ancient evaporite deposits in Utah and Wyoming.<\/p>\n<h4><span style=\"font-weight: 400\">Phosphorus<\/span><\/h4>\n<figure id=\"attachment_4656\" aria-describedby=\"caption-attachment-4656\" style=\"width: 300px\" class=\"wp-caption alignright\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/02\/Apatite-CaF-280343.jpg\"><img class=\"wp-image-4656 size-medium\" title=\"&quot;Rob\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Apatite-CaF-280343-1.jpg\" alt=\"The crystal is hexagonal and light green.\" width=\"300\" height=\"267\"><\/a><figcaption id=\"caption-attachment-4656\" class=\"wp-caption-text\">Apatite from Mexico.<\/figcaption><\/figure>\n<p>Phosphorus is an essential <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1778\">element<\/a> that occurs in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> apatite, which is found in trace amounts in common <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1753\">igneous<\/a> rocks. Phosphorite rock, which is formed in sedimentary environments in the ocean, contains abundant apatite and is mined to make fertilizer. Without phosphorus, life as we know it is not possible. Phosphorous is an important component of bone and DNA. Bone <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1001\">ash<\/a> and guano are natural sources of phosphorus.<\/p>\n<h3>Take this quiz to check your comprehension of this section.<\/h3>\n<div id=\"h5p-109\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-109\" class=\"h5p-iframe\" data-content-id=\"109\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"16.3 Did I Get It?\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_4903\" aria-describedby=\"caption-attachment-4903\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/16.3-Did-I-Get-It-QR-Code.png\"><img class=\"size-thumbnail wp-image-970\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/16.3-Did-I-Get-It-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-4903\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the quiz for section 16.3 via this QR Code.<\/figcaption><\/figure>\n<h1>Summary<\/h1>\n<p>Energy and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">mineral<\/a> resources are vital to modern society, and it is the role of the geologist to locate these resources for human benefit. As environmental concerns have become more prominent, the value of the geologist has not decreased, as they are still vital in locating the deposits and identifying the least <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_991\">intrusive<\/a> methods of extraction.<\/p>\n<p>Energy resources are general grouped as being <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> or <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a>. Geologists can aid in locating the best places to exploit <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1740\">renewable<\/a> resources (e.g. locating a dam), but are commonly tasked with finding <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1739\">nonrenewable<\/a> fossil fuels. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Mineral<\/a> resources are also grouped in two categories: metallic and nonmetallic. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_233_1765\">Minerals<\/a> have a wide variety of processes that concentrate them to economic levels, and are usually mined via surface or underground methods.<\/p>\n<h3>Take this quiz to check your comprehension of this Chapter.<\/h3>\n<div id=\"h5p-110\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-110\" class=\"h5p-iframe\" data-content-id=\"110\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Chapter 16 Review\"><\/iframe><\/div>\n<\/div>\n<figure id=\"attachment_4904\" aria-describedby=\"caption-attachment-4904\" style=\"width: 150px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/slcc.pressbooks.pub\/app\/uploads\/sites\/35\/2022\/03\/Ch.16-Review-QR-Code.png\"><img class=\"size-thumbnail wp-image-971\" src=\"https:\/\/integrations.pressbooks.network\/app\/uploads\/sites\/516\/2022\/05\/Ch.16-Review-QR-Code-150x150.png\" alt=\"\" width=\"150\" height=\"150\"><\/a><figcaption id=\"caption-attachment-4904\" class=\"wp-caption-text\">If you are using the printed version of this OER, access the review quiz for Chapter 16 via this QR Code.<\/figcaption><\/figure>\n<h2><span style=\"font-weight: 400\">References<\/span><\/h2>\n<ol>\n<li style=\"text-align: left\">Ague, Jay James, and George H. Brimhall. 1989. \u201cGeochemical Modeling of Steady State Fluid Flow and Chemical Reaction during Supergene Enrichment of Porphyry Copper Deposits.\u201d <em>Economic Geology and the Bulletin of the Society of Economic Geologists<\/em> 84 (3). economicgeology.org: 506\u201328.<\/li>\n<li style=\"text-align: left\">Arndt, N. T. 1994. \u201cChapter 1 Archean Komatiites.\u201d In <em>Developments in Precambrian Geology<\/em>, edited by K.C. Condie, 11:11\u201344. Elsevier.<\/li>\n<li style=\"text-align: left\">B\u00e1rdossy, Gy\u00f6rgy, and Gerardus Jacobus Johannes Aleva. 1990. <em>Lateritic Bauxites<\/em>. Vol. 27. Elsevier Science Ltd.<\/li>\n<li style=\"text-align: left\">Barrie, C. T. 1999. \u201cVolcanic-Associated Massive Sulfide Deposits: Processes and Examples in Modern and Ancient Settings.\u201d Reviews in Economic Geology, v. 8. https:\/\/www.researchgate.net\/profile\/Michael_Perfit\/publication\/241276560_Geologic_petrologic_and_geochemical_relationships_between_magmatism_and_massive_sulfide_mineralization_along_the_eastern_Galapagos_Spreading_Center\/links\/02e7e51c8707bbfe9c000000.pdf.<\/li>\n<li style=\"text-align: left\">Barrie, L. A., and R. M. Hoff. 1984. \u201cThe Oxidation Rate and Residence Time of Sulphur Dioxide in the Arctic Atmosphere.\u201d <em>Atmospheric Environment<\/em> 18 (12). Elsevier: 2711\u201322.<\/li>\n<li style=\"text-align: left\">Bauquis, Pierre-Ren\u00e9. 1998. \u201cWhat Future for Extra Heavy Oil and Bitumen: The Orinoco Case.\u201d In <em>Paper Presented by TOTAL at the World Energy Congress<\/em>, 13:18.<\/li>\n<li style=\"text-align: left\">Belloc, H. 1913. <em>The Servile State<\/em>. T.N. Foulis.<\/li>\n<li style=\"text-align: left\">Blander, M., S. Sinha, A. Pelton, and G. Eriksson. 2011. \u201cCalculations of the Influence of Additives on Coal Combustion Deposits.\u201d <em>Argonne National Laboratory, Lemont, Illinois<\/em>. enersol.pk, 315.<\/li>\n<li style=\"text-align: left\">Boudreau, Alan E. 2016. \u201cThe Stillwater Complex, Montana--Overview and the Significance of Volatiles.\u201d <em>Mineralogical Magazine<\/em> 80 (4). Mineralogical Society: 585\u2013637.<\/li>\n<li style=\"text-align: left\">Bromfield, C. S., A. J. Erickson, M. A. Haddadin, and H. H. Mehnert. 1977. \u201cPotassium-Argon Ages of Intrusion, Extrusion, and Associated Ore Deposits, Park City Mining District, Utah.\u201d <em>Economic Geology and the Bulletin of the Society of Economic Geologists<\/em> 72 (5). economicgeology.org: 837\u201348.<\/li>\n<li style=\"text-align: left\">Brown, Valerie J. 2007. \u201cIndustry Issues: Putting the Heat on Gas.\u201d Environmental Health Perspectives 115 (2). ncbi.nlm.nih.gov: A76.<\/li>\n<li style=\"text-align: left\">Cabri, Louis J., Donald C. Harris, and Thorolf W. Weiser. 1996. \u201cMineralogy and Distribution of Platinum-Group Mineral (PGM) Placer Deposits of the World.\u201d <em>Exploration and Mining Geology<\/em> 2 (5). infona.pl: 73\u2013167.<\/li>\n<li style=\"text-align: left\">Crutzen, Paul J., and Jos Lelieveld. 2001. \u201cHuman Impacts on Atmospheric Chemistry.\u201d <em>Annual Review of Earth and Planetary Sciences<\/em> 29 (1). 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Anthony. 1975. \u201cDistribution by Latitude of Phanerozoic Evaporite Deposits.\u201d <em>The Journal of Geology<\/em> 83 (6). journals.uchicago.edu: 671\u201384.<\/li>\n<li style=\"text-align: left\">Haber, Fritz. 2002. \u201cThe Synthesis of Ammonia from Its Elements Nobel Lecture, June 2, 1920.\u201d <em>Resonance<\/em> 7 (9). Springer India: 86\u201394.<\/li>\n<li style=\"text-align: left\">Hawley, Charles Caldwell. 2014. <em>A Kennecott Story: Three Mines, Four Men, and One Hundred Years, 1887-1997<\/em>. University of Utah Press.<\/li>\n<li style=\"text-align: left\">Hirsch, Robert L., Roger Bezdek, and Robert Wendling. 2006. \u201cPeaking of World Oil Production and Its Mitigation.\u201d <em>AIChE Journal. American Institute of Chemical Engineers<\/em> 52 (1). Wiley Subscription Services, Inc., A Wiley Company: 2\u20138.<\/li>\n<li style=\"text-align: left\">Hitzman, M., R. Kirkham, D. Broughton, J. Thorson, and D. Selley. 2005. \u201cThe Sediment-Hosted Stratiform Copper Ore System.\u201d <em>Economic Geology and the Bulletin of the Society of Economic Geologists<\/em> 100th . eprints.utas.edu.au. http:\/\/eprints.utas.edu.au\/705\/.<\/li>\n<li style=\"text-align: left\">Hofstra, Albert H., and Jean S. Cline. 2000. \u201cCharacteristics and Models for Carlin-Type Gold Deposits.\u201d <em>Reviews in Economic Geology<\/em> 13. Society of Economic Geologists: 163\u2013220.<\/li>\n<li style=\"text-align: left\">James, L. P. 1979. <em>Geology, Ore Deposits, and History of the Big Cottonwood Mining District, Salt Lake County, Utah<\/em>. Bulletin (Utah Geological and Mineral Survey). Utah Geological and Mineral Survey, Utah Department of Natural Resources.<\/li>\n<li style=\"text-align: left\">Kim, Won-Young. 2013. \u201cInduced Seismicity Associated with Fluid Injection into a Deep Well in Youngstown, Ohio.\u201d <em>Journal of Geophysical Research, [Solid Earth]<\/em> 118 (7). Wiley Online Library: 3506\u201318.<\/li>\n<li style=\"text-align: left\">Klein, Cornelis. 2005. \u201cSome Precambrian Banded Iron-Formations (BIFs) from around the World: Their Age, Geologic Setting, Mineralogy, Metamorphism, Geochemistry, and Origins.\u201d <em>The American Mineralogist<\/em> 90 (10). Mineralogical Society of America: 1473\u201399.<\/li>\n<li style=\"text-align: left\">Laylin, James K. 1993. <em>Nobel Laureates in Chemistry, 1901-1992<\/em>. Chemical Heritage Foundation.<\/li>\n<li style=\"text-align: left\">Leach, D. L., and D. F. Sangster. 1993. \u201cMississippi Valley-Type Lead-Zinc Deposits.\u201d <em>Mineral Deposit Modeling: Geological<\/em>. researchgate.net. https:\/\/www.researchgate.net\/profile\/Elisabeth_Rowan\/publication\/252527999_Genetic_link_between_Ouachita_foldbelt_tectonism_and_the_Mississippi_Valley-type_Lead-zinc_deposits_of_the_Ozarks\/links\/00b7d53c97ac2d6fe7000000.pdf.<\/li>\n<li style=\"text-align: left\">Lehmann, Bernd. 2008. \u201cUranium Ore Deposits.\u201d <em>Rev. Econ. Geol. AMS Online 2008<\/em>. kenanaonline.com: 16\u201326.<\/li>\n<li style=\"text-align: left\">London, David, and Daniel J. Kontak. 2012. \u201cGranitic Pegmatites: Scientific Wonders and Economic Bonanzas.\u201d <em>Elements<\/em> 8 (4). GeoScienceWorld: 257\u201361.<\/li>\n<li style=\"text-align: left\">Mancuso, Joseph J., and Ronald E. Seavoy. 1981. \u201cPrecambrian Coal or Anthraxolite; a Source for Graphite in High-Grade Schists and Gneisses.\u201d <em>Economic Geology and the Bulletin of the Society of Economic Geologists<\/em> 76 (4). economicgeology.org: 951\u201354.<\/li>\n<li style=\"text-align: left\">McKenzie, Hermione, and Barrington Moore. 1970. \u201cSocial Origins of Dictatorship and Democracy.\u201d JSTOR. http:\/\/www.jstor.org\/stable\/27856441.<\/li>\n<li style=\"text-align: left\">Needham, Joseph, Ling Wang, and Gwei Djen Lu. 1963. <em>Science and Civilisation in China<\/em>. Vol. 5. Cambridge University Press Cambridge.<\/li>\n<li style=\"text-align: left\">Nuss, Philip, and Matthew J. Eckelman. 2014. \u201cLife Cycle Assessment of Metals: A Scientific Synthesis.\u201d <em>PloS One<\/em> 9 (7). journals.plos.org: e101298.<\/li>\n<li style=\"text-align: left\">Orton, E. 1889. <em>The Trenton Limestone as a Source of Petroleum and Inflammable Gas in Ohio and Indiana<\/em>. U.S. Government Printing Office.<\/li>\n<li style=\"text-align: left\">Palmer, M. A., E. S. Bernhardt, W. H. Schlesinger, K. N. Eshleman, E. Foufoula-Georgiou, M. S. Hendryx, A. D. Lemly, et al. 2010. \u201cScience and Regulation. Mountaintop<\/li>\n<li style=\"text-align: left\">Mining Consequences.\u201d <em>Science<\/em> 327 (5962). science.sciencemag.org: 148\u201349.<\/li>\n<li style=\"text-align: left\">Pratt, Wallace Everette. 1942. <em>Oil in the Earth<\/em>. University of Kansas Press.<\/li>\n<li style=\"text-align: left\">Qu\u00e9r\u00e9, C. Le, Robert Joseph Andres, T. Boden, T. Conway, R. A. Houghton, Joanna I. House, Gregg Marland, et al. 2013. \u201cThe Global Carbon Budget 1959--2011.\u201d <em>Earth System Science Data<\/em> 5 (1). Copernicus GmbH: 165\u201385.<\/li>\n<li style=\"text-align: left\">Richards, J. 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Simpson. 2003. \u201c2.6-Million-Year-Old Stone Tools and Associated Bones from OGS-6 and OGS-7, Gona, Afar, Ethiopia.\u201d <em>Journal of Human Evolution<\/em> 45 (2). Academic Press: 169\u201377.<\/li>\n<li style=\"text-align: left\">Tappan, Helen, and Alfred R. Loeblich. 1970. \u201cGeobiologic Implications of Fossil Phytoplankton Evolution and Time-Space Distribution.\u201d <em>Geological Society of America Special Papers<\/em> 127 (January). specialpapers.gsapubs.org: 247\u2013340.<\/li>\n<li style=\"text-align: left\">Taylor, E. L., T. N. Taylor, and M. Krings. 2009. <em>Paleobotany: The Biology and Evolution of Fossil Plants<\/em>. Elsevier Science.<\/li>\n<li style=\"text-align: left\">Tissot, B. 1979. \u201cEffects on Prolific Petroleum Source Rocks and Major Coal Deposits Caused by Sea-Level Changes.\u201d <em>Nature<\/em> 277. adsabs.harvard.edu: 463\u201365.<\/li>\n<li style=\"text-align: left\">Vail, P. R., R. M. Mitchum Jr, S. Thompson III, R. G. Todd, J. B. Sangree, J. M. Widmier, J. N. Bubb, and W. G. Hatelid. 1977. \u201cSeismic Stratigraphy and Global Sea Level Changes.\u201d <em>Seismic Stratigraphy-Applications to Hydrocarbon Exploration, Edited by Payton, CE, Tulsa, American Association of Petroleum Geologists Memoir<\/em> 26: 49\u2013212.<\/li>\n<li style=\"text-align: left\">Vogel, J. C. 1970. \u201cGroningen Radiocarbon Dates IX.\u201d <em>Radiocarbon<\/em> 12 (2). journals.uair.arizona.edu: 444\u201371.<\/li>\n<li style=\"text-align: left\">Willemse, J. 1969. \u201cThe Geology of the Bushveld Igneous Complex, the Largest Repository of Magmatic Ore Deposits in the World.\u201d <em>Economic Geology Monograph<\/em> 4: 1\u201322.<\/li>\n<li style=\"text-align: left\">Wrigley, E. A. 1990. <em>Continuity, Chance and Change: The Character of the Industrial Revolution in England. Ellen McArthur Lectures<\/em> ; 1987. Cambridge University Press.<\/li>\n<li style=\"text-align: left\">Youngquist, Walter. 1998. \u201cShale Oil--The Elusive Energy.\u201d <em>Hubbert Center Newsletter<\/em> 4.<\/li>\n<\/ol>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1921\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1921\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1760\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1760\"><div tabindex=\"-1\"><p>Diagenetic copper deposit within sedimentary rocks.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2169\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2169\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1891\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1891\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1920\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1920\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1912\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1912\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_985\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_985\"><div tabindex=\"-1\"><p>The thin, outer layer of the Earth which makes up the rocky bottom of the ocean basins. It is made of rocks similar to basalt, and as it cools, even become more dense than the upper mantle below.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2018\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2018\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2402\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2402\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_977\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_977\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_978\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_978\"><div tabindex=\"-1\"><p>Loose sediment&nbsp;formed by&nbsp;water. This term is typically used by geologists for sediments formed via intermittent water, not rivers.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_979\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_979\"><div tabindex=\"-1\"><p>The layers of igneous, sedimentary, and metamorphic rocks that form the continents. Continental crust is much thicker than oceanic crust. Continental crust is defined as having higher concentrations of&nbsp;very light elements like K, Na, and Ca, and is the lowest density rocky layer of Earth. Its average composition is similar to granite.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_986\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_986\"><div tabindex=\"-1\"><p>A property of a solid, such that when a force is applied, the solid flows, stretches, or bends along with the force, instead of cracking or breaking. For example, many plastics are ductile.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2424\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2424\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_981\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_981\"><div tabindex=\"-1\"><p>The property of unevenly-heated (heated from one direction) fluids (like water, air, ductile solids) in which warmer, less dense parts within the fluid rise while cooler, denser parts sink. This typically creates convection cells: round loops of rising and sinking material.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_982\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_982\"><div tabindex=\"-1\"><p>A zone of earthquakes that descend into the Earth with the subducting slab. This is commonly used as evidence for plate tectonics.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_983\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_983\"><div tabindex=\"-1\"><p>As a rock cools, the iron minerals within the rock align with the current magnetic field. Since the magnetic field changes (by where you are on Earth, by flips where \"north\"and \"south\" switch, and by migration of the magnetic north pole), scientists use the magnetic alignment within rocks to determine past movement or the magnetic field itself, along with the movement of rocks and plates via plate tectonics.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1938\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1938\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_984\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_984\"><div tabindex=\"-1\"><p>The outermost chemical layer of the Earth, defined by its low density and higher concentrations of lighter elements. The crust has two types: <strong>continental<\/strong>, which is the thick, more ductile, and lowest density, and <strong>oceanic<\/strong>, which is higher density, more brittle, and thinner.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_987\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_987\"><div tabindex=\"-1\"><p>A property of solids in which a force applied to an object causes the object to fracture, break, or snap. Most rocks, at low temperatures, are brittle.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_228\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_228\"><div tabindex=\"-1\"><p>QR Code generated with QRCode Monkey. All generated QR Codes are 100% free and can be used for whatever you want. This includes all commercial purposes.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_989\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_989\"><div tabindex=\"-1\"><p>The process of uplifting mountain within mountain belts, primarily via tectonic movement. <strong>Orogenic belts<\/strong> are the mountain belts that result from these movements, and <strong>orogenesis<\/strong> is the name for the process of forming mountain belts.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1725\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1725\"><div tabindex=\"-1\"><p>Period of warming within a glacial or ice age cycle.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1723\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1723\"><div tabindex=\"-1\"><p>A controversial hypothesis which states the entire ocean froze and continental glaciation covered the planet about 700 million years ago.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2003\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2003\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2174\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2174\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_1926\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_1926\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><template id=\"term_233_2038\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_233_2038\"><div tabindex=\"-1\"><\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Fermer la d\u00e9finition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":291,"menu_order":3,"template":"","meta":{"pb_show_title":"","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[49],"contributor":[],"license":[],"class_list":["post-233","chapter","type-chapter","status-publish","hentry","chapter-type-numberless"],"part":19,"_links":{"self":[{"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/pressbooks\/v2\/chapters\/233","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/wp\/v2\/users\/291"}],"version-history":[{"count":2,"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/pressbooks\/v2\/chapters\/233\/revisions"}],"predecessor-version":[{"id":1792,"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/pressbooks\/v2\/chapters\/233\/revisions\/1792"}],"part":[{"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/pressbooks\/v2\/parts\/19"}],"metadata":[{"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/pressbooks\/v2\/chapters\/233\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/wp\/v2\/media?parent=233"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/pressbooks\/v2\/chapter-type?post=233"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/wp\/v2\/contributor?post=233"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/integrations.pressbooks.network\/testcloneglossaryterms\/wp-json\/wp\/v2\/license?post=233"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}