Introduction to Mineralogy

Mineralogy Basics

• Mineralogy involves the study of minerals, and a mineralogist is someone who performs mineral studies.
• A mineral is a naturally occurring solid inorganic object possessing a defined chemical structure.
• Rocks lack a defined chemical structure, differentiating them from minerals.
• Every mineral has a mineral name and a chemical name.
• Thenardite, a mineral, has the chemical name sodium sulfate, and magnesite has the chemical name magnesium carbonate.
• Halite has the chemical designation sodium chloride in addition to the popular names rock salt or table salt, and hematite is also known as rust and has the chemical formula ferric oxide.

Mineral Identification Properties

• Minerals can be uniquely identified by various properties.
• Color can help identify a mineral but is the least reliable method because it can vary even within the same mineral type.
• Streak refers to a mineral's color as a powder, which is more reliable than its solid form color.
• Luster refers to how light reflects off a mineral and can be metallic (highly reflective) or dull (no reflection).
• Transparency describes how well a mineral transmits light, which can be transparent (easily transmits), opaque (does not transmit), or translucent (partially transmits)

Mineral Hardness and Tenacity

• Hardness refers to a mineral's resistance to scratching or rubbing, which can be compared between two minerals.
• If one mineral scratches another, it is harder.
• The Mohs scale quantifies hardness from 1 to 10.
• Friedrich Mohs defined the Mohs scale in 1812.
• Talc is the least hard mineral (1 on the Mohs scale), and diamond is the hardest (10 on the Mohs scale).
• Diamond is a form of carbon and can only be scratched by another diamond.
• Tenacity refers to a mineral's resistance to breaking or deforming, and is described with terms like brittle or malleable.
• There is no scale analogous to the Mohs scale to describe tenacity.

Cleavage, Density and Other Properties

• Cleavage describes how a mineral breaks based on its crystal geometry.
• Cleavage types include cubic (right angles), diagonal (slanted angles), and lateral (thin sheets).
• Habit describes a mineral's crystal geometry when unconstrained.
• Habit types include equant (equal angles), bladed (rods), and fibrous (long threads).
• Density is the ratio of mass to volume and can be measured by immersing a solid in liquid.
• Specific gravity is the density of a mineral compared to the density of liquid water.
• A specific gravity of 2 means the mineral is twice as dense as water and will sink.
• Other properties include taste, smell, and magnetism.
• Minerals can be classified based on their chemical composition using these properties.

Silicate Minerals

• Silicate minerals, based on the silicon-oxygen tetrahedral group SiO44–, are the most abundant.
• Silicon and carbon atoms can both form covalent bonds with four other atoms in a tetrahedral geometry.
• This allows for almost infinite diversity in molecules based on either atom type.
• Organic molecules are based on carbon and are the basis of all life on Earth, including carbohydrates, lipids, proteins and nucleic acids.
• 90% of all minerals are silicate, demonstrating their enormous category size.
• Silicon-oxygen bonds are strong enough to make silicate minerals, but Silicon-silicon bonds are not strong enough.
• Silicon atoms in silicate minerals are always separated by an oxygen atom.
• Metals like iron and magnesium can bond with silicon atoms in silicate minerals.
• Hydrogen, oxygen, and nitrogen bond with carbon atoms in organic molecules making it analogous to metals bonding with silicon atoms in silicate minerals.
• Theoretically, like could evolve on another planet based on silicate minerals because of their nearly infinite diversity of molecules.

Silicate Mineral Structures

• The most simple silicate mineral is a single silicon atom covalently bonded to other atoms: nesosilicates (e.g., olivines, garnets).
• Topaz and kyanite are also nesosilicate minerals.
• Chemically bonding two nesosilicates yields sorosilicates (double nesosilicates), such as epidotes.
• Chemically bonding another nesosilicate to a sorosilicate (a double nesosilicate), yields triple nesosilicates .
• Constructing long chains of silicon atoms bonded to one another yields one-dimensional, single-chain inosilicates, like pyroxenes.
• Chemically bonding two single-chain inosilicates yields double-chain inosilicates such as the amphiboles
• Constructing single-sheet phyllosilicates include the serpentines and the micas.
• Chemically bonding single-sheet phyllosilicates yields double-sheet phyllosilicates which can be 3-D tectosilicates (zeolites, feldspars, quartz).

Silicate Mineral Ratios

• Nesosilicates have the highest oxygen-to-silicon ratios and the most metals (iron, magnesium) bonded with silicon.
• In single-chain inosilicates, oxygen-to-silicon ratios get smaller with decreased metals and more silicon-oxygen bonds, leaving fewer places for metals to bond with silicon atoms.
• The progression continues through double-chain inosilicates to single-sheet phyllosilicates.
• Single-sheet phyllosilicates progress to double-sheet phyllosilicates, and eventually to tectosilicates.
• Tectosilicates have the lowest oxygen-to-silicon ratios, least metals, and the tectosilicate mineral quartz is pure silicon and oxygen, with no other atoms.

Dark, Intermediate and Light Silicates

• Nesosilicates and sorosilicates are dark silicates, whose color is a result of the high metal abundance.
• Tectosilicates lack color and are light silicates.
• Located in between the two are inosilicates and the phyllosilicates (intermediate silicates), with intermediate metal amounts which gives them an intermediate color.
• Metals in the dark silicates increased density.
• Few metals in the light silicates results in decreased density.
• Dark silicates have the highest melting temperatures, while light silicates have the lowest.
• Dark silicates, including olivines, garnets, and epidotes have the least complex chemical structures.
• Light silicates, including zeolites, feldspars, and quartz have the most complex chemical structures.

Additional Silicate Classifications

• Pyroxenes, amphiboles, serpentines, and micas are all intermediate silicates.
• Dark silicates possess the greatest abundance of metals, darkest color, highest densities, warmest melting temperatures, highest oxygen-to-silicon ratios, and least complex structure.
• Light silicates possess the least abundance of metals, lightest color, lowest densities, coolest melting temperatures, lowest oxygen-to-silicon ratios, and most complex structure.
• Organic rings are comparable to cyclosilicates, for example, three-silicon rings - the benitoites. four-silicon rings - the axinites and six-silicon rings - the beryls and tourmalines.

Non-silicate minerals

• Most minerals are silicate minerals, but some are other mineral group, for example the sulphates are the mineral group where the sulfur-oxygen tetrahedral group SO42– bonds with metals.
• The chemical symbol of silicon is Si, S is the symbol for sulfur.
• Gypsum (calcium sulfate CaSO4), anglesite (lead sulfate PbSO4), and thenardite (sodium sulfate Na2SO4) are examples of sulfate minerals.
• Epsomite (magnesium sulfate MgSO4) has a low Mohs hardness and is known as epsom salt.
• Carbonates are a mineral group where the carbon-oxygen trigonal planar group CO32- bonds with metals.
• Calcite (calcium carbonate CaCO3), magnesite (magnesium carbonate MgCO3), and dolomite (calcium magnesium carbonate CaMg(CO3)2) are examples of carbonate minerals.
• Dolomite is named after Déodat de Dolomieu, a French geologist.
• Oxides are minerals where oxygen bonds with metals, such as iron (hematite, magnetite, wüstite), aluminum (corundum), and copper (cuprite, tenorite).
• Iron oxides are commonly red, while copper oxides are often green.
• The green color of the Statue of Liberty is due to the oxidation of its copper components from its original orange color.
• Halides are minerals where halogens (fluorine, chlorine, bromine, iodine) bond with metals for example Halite (sodium chloride NaCl).
• Fluorite (calcium fluoride CaF2), bromargyrite (silver bromide AgBr), marshite (cuprous iodide Cul) and sylvite (potassium chloride KCl) are examples of halide minerals.
• Sulfides are minerals where sulfur bonds with metals, such as pyrite (iron disulfide FeS2, fool's gold), sphalerite (zinc sulfide ZnS), Galena (lead sulfide PbS) , cinnabar (mercury sulfide HgS).
• Native elements are minerals composed of a single type of metal, such as pure aluminum, iron, nickel, copper, zinc, silver, tin, platinum, gold, and lead.

Gemstones

• Gemstone refers to either a mineral or rock with beautiful appearance when cut and polished, making it economically valuable.
• Pearls, amethysts, emeralds, rubies, sapphires, and diamonds are historically the economically valuable gemstones and are the primary (or cardinal) gems.
• Natural pearls are polished forms of the carbonate mineral calcite developed by clams, oysters and mussels.
• Amethysts are forms of the tectosilicate mineral quartz, where small amounts of metallic impurities within quartz result in a beautiful violet color.
• Emeralds are forms of the cyclosilicate mineral beryl, where small amounts of metallic impurities within beryl may give it a beautiful green color.
• Rubies and sapphires are forms of the aluminum oxide mineral corundum, where If small amounts of metallic impurities within give it a beautiful red color, then it becomes a ruby and a sapphire if blue in color.
• A mineral diamond (one of the mineral forms of carbon and is the most hard mineral on the Mohs scale) corresponds to said gemstone after cutting and polishing.

Petrology

• Petrology involves the study of rocks, and petrologist are the scientists who perform studies on rocks.
• Petrology is derived from the Greek root petro- for rock.
• Rocks are naturally occurring solid inorganic objects and an aggregate (a mixture) of minerals.
• Rocks lack a definite chemical structure, differentiating them from minerals.
• Rocks have significant density and composition variations, even within the same rock type.
• Petrography is the classification, while petrogenesis is the study of how different types of rocks form.
• Igneous, sedimentary, and metamorphic rocks are the 3 broad categories of rocks.

Igneous Rocks

• Molten rock (liquid rock) melts and then cools to crystallize creating solid rock.
• Any rock that forms from the crystallization of molten rock is called igneous rock.
• Molten rock beneath the Earth is referred to as magma, and molten rock that is has extruded out of the earth is called lava.
• Magma that crystallizes into solid rock is called intrusive igneous rock, since it forms deep within the Earth.
• Lava that crystallizes into solid rock is called extrusive igneous rock, since it formed from lava that extruded out of the earth.
• Intrusive igneous rock is also called plutonic igneous rock, and extrusive igneous rock is also called volcanic igneous rock.
• Intrusive/plutonic igneous rocks typically take a long time to cool and crystallize, creating large crystals and a coarse-grained texture.
• Extrusive/volcanic igneous rocks typically take a short time to cool and crystallize, thus limiting crystal size and creating a fine-grained texture.
• Phaneritic describes the coarse-grained texture of igneous rocks as the crystals are visible with the naked eye, the Greek root phanero- means visible.
• Aphanitic describes the fine-grained texture of igneous rocks as the crystals are too small to be visible with the naked eye, the Greek root a- means no or not.
• Pegmatitic describes the extremely coarse-grained texture of an igneous rock that takes an extremely long time to cool and crystalize.
• In contrast, quenching refers to virtually instantaneous crystallization in an igneous rock.
• Where an igneous rock obtains an extremely fine-grained texture called glassy and feels smooth like glass
• Obsidian is an extrusive/volcanic igneous rock has a glassy texture by quenching.
• Pumice is an extrusive/volcanic igneous rock with a glassy texture due to quenching, which has a density less than water allowing it to float.
• The cooling history of an igneous rock can be determined by feeling its texture.
• Porphyritic texture occurs when there is an interruption in the cooling history of the rock having both large crystals (phenocrysts) and small crystals (groundmass) in the same rock.

Igneous Rock Composition Classifications

• Igneous rocks are comprised mostly of silicate minerals, and are categorized based on silicate mineral composition.
• Mafic igneous rocks consist predominantly of dark silicates with the most metals (magnesium and ferrum), and are dark in color and most dense.
• Felsic igneous rocks consist predominantly of light silicates (feldspar and silica), and are lightest in color and least dense.
• Intermediate igneous rocks consist predominantly of intermediate silicates.
• Mafic igneous rocks have the hottest melting temperatures, while felsic have the least.
• The Bowen reaction series describes the spectrum of melting temperatures for igneous rocks, where felsic rocks melt first and then intermediate rocks and mafic rocks melt last if more heat is added.
• The two most important mafic igneous rocks: basalt and gabbro with large quantities of metals, are dark in color, have high densities, and have hot melting temperatures.
• Gabbro forms intrusively/plutonically deep within the Earth and forms with large crystals resulting in a coarse-grained texture whereas Basalt forms extrusively/volcanically and forms with small crystals with a fine-grained texture.
• The two most important felsic igneous rocks: rhyolite and granite with small quantities of metals, are light in color, have low densities, and have low melting temperatures.
• Granite forms intrusively/plutonically deep within the Earth, where rhyolite forms extrusively/volcanically.
• The two most important intermediate igneous rocks: andesite and diorite with intermediate quantities of metals, are intermediate in color and have intermediate melting temperatures.
• Diorite forms intrusively/plutonically, while andesite forms extrusively/volcanically.

Sedimentary Rocks

• Sedimentary rocks form through the lithification (meaning that they have become rock) of sediment with the three subcategories: clastic, chemical, and biogenic sedimentary rocks.
• Clastic sedimentary rock lithifies through the action of physical forces.
• Rocks with Large sediments have a coarse-grained texture rocks, while small sediments have a fine-grained.
• The Wentworth scale is named after American geologist Chester K. Wentworth who defined the scale which classifies sediment size.
• Sediments are classified by the Wentworth scale as gravels, sands, silts, or clay/mud, based on their size.
• The largest sediments are gravels, lithifying into coarse-grained clastic rocks either conglomerate (if composed of rounded sediments) or breccia (if composed of angular sediments).
• Sands are somewhat smaller sediments that lithify into sandstone.
• Silts are even smaller sediments that lithify into siltstone.
• Clay/mud are the smallest sediments lithifying into shale.
• Resulting sediments form with irregualr and jagged shapes, but angular shapes result when sediments haven't eroded far.
• Sediments that moved over a far distance and collided with each other are known as rounded.
• Clastic sedimentary rocks form from sediments that are either poorly sorted (all different sizes) or well sorted (all roughly the same size)
• Major rivers can move many differently sized sediments which means that the resulting clastic sedimentary rocks will poorly sorted.
• In contrast, a small stream sorts its transported sediments better, which means that the resulting clastic sedimentary rocks well sorted.
• Giants mass like glaciers move giant boulders and as well as small sediments, forming clastic sedimentary rocks by glaciers will also be poorly sorted.
• Chemical sedimentary rocks lithifies through the process of chemical reactions for example limestone ( the mineral calcite), dolostone (the mineral dolomite). and chert (the tectosilicate mineral quartz).
• Biogenic sedimentary rock lithifies from organic materials or liveforms that contain inorganic sediments coal, coquina and chalk are three examples of biogenic rocks.

Rock and Hydrothermal Metamorphism

• Chalk forms from the lithification of microscopic ocean plankton. It is an artifact artificially made from the minerals gypsum and calcite.
• Coquina is from many different types of shells from many different types of shells from invertebrate animals.
• Bituminious Coal forms through the compaction of plant layers, clay and mud which prevents decomposition of the the matter it it compressed over time causing sediments which over compress it which causes it become compressed with the classification of brown coal.
• If it is compressed to even higher densities over millions of years, it is eventually lithified to the biogenic sedimentary rock bituminous coal.
• Bitumious coal will become anthracite if it continously receives higher pressures, but that may become graphite a mineral from carbon from continuous pressures which becomes diamond, another carbon mineral from compressions millions of years.
• Fossil fuels are: petroleum (crude oil), natural gas, and coal coal is formed where plants are compacted over high pressures causing natural oil to turn into fossil fuels.

Rock Metamorphism

• Metamorphic rock forms as a result of changing a pre-existing rock which is a parent transformed into a duaghter as a new metamorphic rock due to the influence of heat, pressure and chemicals through contact, regional, and hydrothermal morphic metamorphism where heat and pressure has lower effect.
• Regional means the opposite as pressure and chemistry has lower effect. Hydrothermal means higher effect of chemistry and lower effect of press and chemicals.
• Subclassification occurs on their shape like a folded metamoprhic with asymmetrical stress or a nonfolded shape.
• Siltstone or Schale can become the duaghter foliated metamorphic rock Slate caused by applied assymetrical pressures where as Slate can be applied similarly to result in phyllite.

Core-Mantle Metamorphic States

• The daughter Schist can be aparent then become Gneiss with assymetrical pressures. Bituminous nonfoliated can apply symmetrical pressures cause anthracite.
• Sedimentary rocks marble and dolostone can form Non foliacated rock by Quartzite.
• Schale results also with nonfoliated rock by hornedis.
• Molten rock may cool becoming igneous and metamorphic rocks can be thrust by events into sediment to become part what they do.
• In summery rocks continuously change that rock cycle being dynamic and not static to our planet continuously altering rock changes

Magma and Rock Variations

• The rock is not melted as heat changes a parent into a duaghter.
• Rock that is melted and recrystallized means they reclassified as a igneous kind and cannot be a metamorphic.
• There are some parts when the molten parts change others that heat them. If rock forms crystallization than it cannot be classified such as tuff that can form as crystallization which means these rocks that cannot be classified as igneous, sedimentary, or metamorphic where there are also exceptions like marlstone that is also cant be classified because of chemicals and sediment.

Land Surface

• Earth which is covered by oceans contains continents that are composed of Mostly felsic rock containing sedimentary on top when driling through continents and having crust composed of silicate rock.
• Under the ocean which is mafic composed surface composed sedimentary.
• A core exists under the surface which is iron and nickel but less dense than mantle. Mantle rock contains irion rich silicate but less is the crust composed iron poor siliate rock that is iron poor.
• In the most center Earth contains metal iron and nickel in the inner which is solid like and outer which is also primarily iron but molten. The molten layer has mesosphere middle layer. Asthenosphere weal layer which mostly solid except most it that gets partially melted. The rest of the mantle and the center of it that calls the lithodphere.

Density and Mass

• Density is as mass divides by volume volume with inverse with denister rock occupying the smaller volume that causes continents that is less denser then mafic.
• Direct study on the layers like drill is impossible and that is what the misconstrued. Seismic waves help.
• Million each days caused thousands with seismometers.
• Body seismic waves cause surfaces that have pressure and sheer stress. A force that is perpendicular equals pressure.
• Solid liquids has collision by atoms and molecules.

P. And S. Waves

• Seismic waves that cause chemicals means P waves because chemicals cause the pull but if you compare shear stress which is S waves to be a secondary.
• Seismic detects always pressure faster. The P waves S waves in distance and that shows the quake.
• It shows the location of quake but not how long. Time of drop and know how speed equal with timing. Since know anything the interior of Earth at least partially molten.
• As we discussed S waves cannot reach liquids so only propagate through solids while the opposite of planet cannot see S we dont see S from liqued for P waves only is it shadow or is it.

Mohorovičić discontinuity

• There layers the thickness composition and physical the device name
• Each million different millions earthquake that occurs for everyday data
• Earth by running simulations composition, physical states, the first use
• Created created was when the scientist Andrija Mohorovičić when he
• Created in the seismic waves when in 1909 . Consequently, 1 in his honor

The Planet Formations

• Higher layers cause from layers. Each billion years forming 4 planets.
• Stick collision each which increase heat and the earth grows through growing a lot to the center and lesser amount towards the surface.
• Different planets that is small for example dont a contain a as big mass like Earth. Therefore, the mars as weaker center that as weak metals towards Mars than we find oxidation.
• Older theories on magnetic sphere but only from our solar winds caused. These charged areas that align and particles which travels though

Earth Magnetosphere

• Energetic wind part Earth can be destroyed the Sun that protect to Solar is not be wind this is known as aurora in magnetic from known as borealis that
• Is in the north as australis which means the south.
• Solar wind can weakers aurora we dont see Earth that
• Our core that inner energy geologic is decayed has stabilize atomic atoms which radiate.
• The energy that drives radioactive geothermal planet long have greater. We have now we have the geothermal has to.

Conduction, Convection and Radiation

• Conduction from direct heat through contact. Covenction moving
• That can hot air. In ohysics fluids can gas liqiids
• To air the heater warmer to heat the Sun but god heat of the

Plate Tectonics

• Christopher Columbus discovered america after Italian Amerigo world the maps and Africa and Europe to together north Africa and Europe America the of world and earth Holmes envisioned