Rocks and Minerals

Quartz (Chalcedony)

-AKA Compact Microcrystalline quartz -White, gray, bluish, greenish gray, yellowish, brown, deep red and green, Rarely bright blue, yellow, or pink. -Slightly porous: can absorb dyes, can be artificially colored. -Streak: white -Botryoidal masses, replacements in fossils, other minerals, or wood fibers, in geodes as a cementing matieral, deposited under moderate- to low- temperature conditions. -Luster: waxy, vitreous, dull -Cleavage: none -Crystal system: hexagonal -Fracture: conchoidal -Tenacity: brittle -Smooth and translucent -Fluorscent -Dissolves in hydroflouric acid

Gypsum (Satin Spar)

-CaSO4 2H2O -Class: Sulfate -Found in Australia, Canada, Nova-Scotia, Italy-Abruzzo and Tuscany, USA -Luster: silky -Hardness: 2.3-2.4 -SG: 1.2-2 -Streak: white -Luster: vitreous, pearly -Crystal: fibrous, fish-tail twinning**** -Fracture: fibrous -Environment: chemical sedimentary rocks forms gypsum deposits in beds, hydrothermal replacement deposits

Gypsum (Selenite)

-CaSO4 2H2O -Class: Sulfate -Luster: vitreous, pearly -Transparent*************** -Fracutre: micaceous -Found in Utah, Mexico, Morocco, Madagascar -Degrades in winter -Crystal system: monoclinic -Crystal habit: tabular -Hardness: 2 SG: 2.3 -Cleavage: perfect in one, distinct in two -Fracture: conchoidal, fibrous -Streak: white -Uses: flux for creating eathenware, fertilizer -Same environment and crystals and all other gypsum

Quartz (Jasper)

-Crystal habit: massive microgranular quartz -Crystal system: hexagonal -Index of refraction: 1.54-1.55 -Luster: dull, vitreous to greasy -Cleavage: none -Fracture: conchoidal -Streak: white -opaque chalcedony, commonly dark red, red-brown, or yellowish-brown, pigmented by finely divided hematite or goethite particles.

Quartz (Milky)

-Crystal system: trigonal -Cleavage: none -Index of Refraction: 1.544-1.553 -Birefringence: .009 -Associated with gold in hydrothermal veins -Luster: vitreous, greasy -Streak: white, milk-white, whitish -most common type, frequently occurs as masses in pegmatites and hydrothermal veins. -color caused by microscopic liquid inclusions or flaws that scatter light. Large crystals common.

Gold

-Distinctive Characteristics Soft, malleable -Class: Native Element -Streak: golden yellow -Hardness: 2.5-3 -SG: 19.3*** -Insoluble in single acids -Fracture: hackly -Malleable and ductile -Uses: gold ore, jewelry, utensils, pins -Environment: clastic placer, sedimentary deposits, veins, igneous rocks and hydrothermal replacement depsosits -Luster: metallic -Crystals: isometric- octahedral, dodecahedral and cubic Name: Name: From Anglo-Saxon "gold", yellow; Latin "aurum".

Galena

-Distinctive Characteristics: Cubic cleavage, lead-gray metallic color and luster. Might be confused with dark sphalerite, but light streak of the latter would permit a distinction. Other similar sulfides have good cleavages in a single direction, but not in three. Also dense as hell. Ore of silver. Galena with flaky curvy cleavage planes, as opposed to smooth and slightly tarnished ones, are said to be higher in silver impurities. -PbS -Class: Sulfides -Luster: metallic -Streak: gray -Hardness: 2.5 -SG: 7.4-7.6 -Cleavage: perfect cubic -Fracture: subconchoidal -Uses: Most important ore of lead. Frequently contains enough silver to be mined as a silver ore. Used in storage batteries and in various alloys as a solder. Also used in manufacturing of pigments. -Name: From Greek "galene", lead ore

Graphite

-Distinctive Characteristics: Greasy feel, softness, foliated habit, micaceous cleavage, and low SG. -C: strategic mineral -Class: Native Element -Uses: lubricant for chemical and electrical purposes, pencils, neutron mederators -one of the softest minerals--> Hardness:1 -Environment: igenous and metamorphic rocks, schists and marbles. Mainly in metamorphic rocks (schist) -Fracture: micaceous -SG: 2 -Found in Alabama, Texas, RI as commercial deposits; Korea, Ceylon, Mexico and Madagascar -Streak: shiny, gray to black -Luster: metallic, shiny -Cleavage: perfect in one direction -Thin flakes are flexable, sectile -Feels greasy -Crystal: hexagonal -Crystals: tablets, foliated, scaly, granular, earthy. Rhombohedral faces on the edges. -Random: Old world name "plumbago" or black lead: use in lead pencils. Also used as a lubricant and in crucibles as a refractory. Outstanding example of the relation of internal atomic arrangement to physical properties--SG 2.3, soft, opaque. -Name: Name: From Greek "graphein", 'to write'; named by German chemist and mineralogist A. G. Werner in 1789

Corundum

-Distinctive Characteristics: Resembles many silicate minerals. Fine parallel rulings on parting faces are distinctive and might result in confusion with some feldspars. Often shows color bands and bronzy luster on basal planes. Great hardness is diagnostic. Crystal form and high SG. -Al2O3 -Simple oxide, Hematite group -*Third hardest mineral -Hardness: 9 -Crystals: hexagonal -Fracture: tough, uneven, conchoidal -SG: 4 -Density: 3.98-4.1 -Crystal system: hexagonal*** -Luster: adamantine, vitreous, pearly -transparent, traslucent, opaque -Streak: white -Cleavage: none -Parting: rhombohedral, basal -Environment: Acessory mineral in igneous rocks that are poor in silica, in metamorphosed limestones and mica schists, and pegmatites. Rubies and sapphires occur with red spinel in clay. -Location: Kashmir, Ural Mountains, Queensland, Afghanistan, Helena, Montana, North Carolina, South Africa, Madagascar, Ontario, Greece, Peekskill, NY, Chester, MA. -Associated minerals: magnetite, hematite, spinel, tourmaline, micas, chlorites, garnet. -Uses: abrasive, gem material, bearings in watches, scientific instruments. -Tenacity: brittle -Name: Derived from the Sanskrit, kuruvinda ("Ruby") -Random: there's a huge industry for synthetic corundum: Verneuil process since 1902.

Goethite/ Limonite

-Distinguished from hematite by its streak, and from limonite by its structure (silky, fibrous, radiating). Magnetism after heating distinguishes it from most other minerals. Limonite is basically goethite without the fibrous and silky appearance on a fresh break. Distinguished by streak and magnetism, also. -FeO(OH) -Class: hydroxide -derived by weathering from iron-bearing minerals -Crystal: orthorhombic -Crystal: acicular, flattened plates, granular, foliated, earthy -Tenacity: brittle -Opaque -Luster: metallic to dull -Hardness: 5-5.5 -SG: 3.3-3.5 -Environment: formed under oxidizing conditions as weathering product of iron minerals. Commonly found in old bogs formed by direct precipitation of water. Rarely in low-temperature hydrothermal veins. Frequently form a gossan. -Found in England, Cuba, Michigan, Minnesota, Colorado, Alabama, Tennesse, Georgia, Virginia -Streak: yellow/ yellowish brown -Cleavage: perfect, one direction -Fracture: uneven, splintery -Use: iron ore and pigment. -Name: For German poet, novelist, playwrighter, philosopher and geoscientist Johann Wolfgang von Goethe (1749-1832)

Dolomite

-Distinguishing Characteristics: "Pearl-spar" white to pinkish crystal intergrowths are readily recognizable. Slow effervescence in cold acid distinguishes it from calcite (rapid) and magnesite (only in hot acid). SMALL, PINK, CURVED CRYSTALS. -MgCa(Co3)2 -Class: Carbonate -Nonmetallic -Uses: ore of magnesium for industrial and medical uses -Fracture: conchoidal -Hexagonal -Crystals: rhombohedral -Twinning common -Luster: pearly, vitreous -Streak: white -Hardness: 3.5-4 -SG: 2.8-2.9 -Cleavage: perfect in three directions -Tenacity: brittle -Alteration: From calcite and aragonite by action of magensium-rich solutions. Metamorphosed dolomite frequently dissociates into calcite, may also combine with silica to form calcium magnesium silicates (diopside). -Environment: develops in chemical sedimentary rocks, contact/ regional metamorphic rocks, hydrothermal/ mesothermal/ epithermal veins with fluorite, and in disseminated replacement deposits. Use: building material, cements, manufacture of magnesia, source of magnesium. -Name: Named in 1791 after the French mineralogist and geologist, D. de Dolomieu (1750-1801).

Ulexite

-Distinguishing Characteristics: "TV Stone" soft, loose-textured, white, silky cotton ball aggregates, also transparent ones with fantastic birefringence. -NaCa(B5O6(OH6)) . 5H2O -Class: borate -Hardness: 2.5 -Triclinic, pinacoidal -SG: 1.9-2 -Luster: vitreous, silky -An evaporite mineral found in borax (Mojave Desert, Chile, Argentina, Peru) -Crystals: usually soft white cottony masses of loosely intergrown fibrous crystals. Also known as "cotton balls" or "Sheet cotton"-Streak: white -Cleavage: perfect -Fuses easily -Use: source of borax -Alters to gypsum. Name: Named after George Ludwig Ulex (1811-1883), German chemist, who first correctly analyzed the species.

Tremolite

-Distinguishing Characteristics: (Actinolite) Fibrous Habit and Cleavage -(Ca2)(Mg5)(Si8O22)(OH)2 -Class: inosilicate -Crystal system: monoclinic -Crystal habits: bladed, fibrous radiating aggregates, compact -Transparent- opaque -Cleavage: typical about 56 degrees -Fracture: uneven -Hardness: 5-6 -SG: 3-3.44 -Found in New Zealand, England, Japan -Uses: gemstone, industrial applications -Environment: product of metamorphism, found in hornfels of contact and serpentinites of hydrothermal metamorphic rocks -Streak: colorless, white to darkish gray, yellowish, lilac, colorless -Luster: vitreous, silky -Cleavage: perfect in two directions forming a diamond -Alters to talc, alters from pyroxenes -Name: Named by J.G.A. Höpfner for the Tremola valley (Val Tremola), Central St Gotthard Massif, Switzerland, where the type material supposedly came from, according to the dealer from whom he had acquired the specimens. However, modern investigations of what is considered the type material, conserved at Geneva, revealed that the true type locality is Campolungo. (Val Tremola lying north of the isograde delineating the first appearance of tremolite).

Sphalerite

-Distinguishing Characteristics: (Zinc Blende, Hack Jack). ADAMANTINE LUSTER ON CLEAVAGES! Galena has cubic cleavage and dark-gray streak. -ZnS -Class: Sulfide -Streak: light brown, yellow, brown, red, green, black -Crystal habit: commonly tetrahedral or dodecahedral after distorted with rough curved faces (best example of dodecahedral cleavage in a mineral!) -Crystal system:isometric -Twinning common -Transparent to translucent -Luster: submetallic, adamantine, resinous -Hardness: 3.5-4 -SG: 3.9-4.1 -Fracture: conchoidal -Uses: principal zinc ore, also important source of cadmium, gallium, indium, thallium, and germanium. Metallic zinc is used for galvanizing iron, and for manufacturing brass, wire, sheet zinc, cell phone phone batteries, white paint. -Associations: galena, pyrite, chalcopyrite, calcite. -Environment: occurs with galena very often. In limestone deposits, hypothermal/ mesothermal veins, and in massive/ lode/ disseminate hydrothermal replacement deposits -Name: From Greek "sphaleros", treacherous, in allusion to the ease with which dark varieties were mistaken for galena, but yielded no lead. -triboluminescence: fluorescent variety emits flashes of orange lights on being lightly stroked with a hard surface such as a knife or a stone.

Opal

-Distinguishing Characteristics: Broken fragment may be confused with quartz, but opal is softer. Resembles chalcedony, but opal has lower hardness and a greasy luster. -SiO2 . nH2O -None crystalline form of quartz -Class: tectosilicate -Environment: forms in low temperatures, deposit around hot springs and in veins -Hardness: 5.5-6.5 -SG: 2.1 -Luster: glassy, pearly, or resinous -Streak: white -Fracture: conchoidal -Black opal most highly prized -Use: jewelry, common opal has no value except that it's cool because it's fluorescent. -NO CRYSTALS*** (except in pseudomorphs) -Locations: deposited by hot water in Yellowstone, Wyoming, Nevada, Hungary, Idaho, California, Australia, North Carolina. -Name: From the Sanskrit "upala", meaning "stone" or "precious stone"

Hematite

-Distinguishing Characteristics: Brownish-red streak, even in black varieties (distinguish from limonite), hardness, magnetism after roasting, -Fe2O3 -Class: simple oxide -Hardness: 4.9-5.3 -SG: 5-6 -Streak: cherry red -Fracture: regular, uneven -Associated: magnetite, limonite, goethite, ilmenite, chacledony. -Uses: iron ore, pigment, polishing powder. -Found in Minnesota, Michigan, Wisconsin, and adjacent calendar -Environment: sedimentary, quartz, carbonatites, contact regional metamorphic rocks, mesothermal/ epithermal veins, in lode and disseminated replacement deposits -Name: From the Greek, haimatites, "bloodlike" in allusion to vivid red color of the powder

Sodalite

-Distinguishing Characteristics: Color, -Na8(Al6Si6O24)Cl2 -Class: tectosilicate -Cleavage: none well developed but in 6 directions -Crystal habit: rare, dodecahedron, compact disseminated grains, nodular -Crystal system: isometric -Hardness: 5.5-6 -SG: 2.27-2.33 -Fracture: uneven to conchoidal -Transparent to translucent, flourscent -Tenacity: brittle -Uses: gemstone -Streak: white, blue, bluish gray, colorless, green -Luster: vitreous, glassy -Environment: forms only in silica-poor igneous rocks, develops in nepheline syenite pegmatites. In alkaline igenous and plutonic rocks. -Locations: Onatio, BC, Maine, Vesuvius. Name: The name reflects its sodium content.

Pyrite

-Distinguishing Characteristics: Color, luster, hardness, crystal form. Distinguishable from Chalcopyrite by superior hardness, from gold by brittleness. -FeS2 -Class: sulfide -Uses: source of Fe, sulfuric acid -Fracture: irregular, uneven -Hardness: 6 -SG: ~5 -Crystal system: isometric. Often occurs in striated cubes, pyritohedrons, octahedron, or combination. "iron-cross" twins are common. -Streak: greenish black -Luster: sometime iridescent, metallic -Associations: other sulfides, (sphalerite, chalcopyrite, galena) -Alterations: Limonite or goethite often form pseudomorphs after pyrite crystals. -Use: source of sulfur for sulfuric acid and ferrous sulfate, also yields impure iron when roasted, some mined for associated gold and copper. -Location: Spain, Rio Tinto, Arizona, Coloradom California, Vermond, Illinois, Utica, NY, Long Island. -Name: Named in antiquity from the Greek "pyr" for "fire", because sparks flew from it when hit with another mineral or metal.

Chalcopyrite

-Distinguishing Characteristics: Confused with gold, but is brittle, gives black streak and dissolves in acid. Distinguished from pyrite by ease of scratching and by copper tests. Color is slightly more yellow than that of pyrite, but on a fresh surface, pyrite is lighter brass yellow. Pyrite will frequently show striated cubes or pyritohedra, whereas chalcopyrite, if not massive, is in characteristic spheniodal crystals. -CuFeS2 -Crystals: Tetragonal; scalenohedral. Usually sphenoidal but resemble tetrahedrons. Usually massive. -Hardness: 3.5-4.5 -SG: 4.1-4.3 -Color: brass yellow -Streak: greenish black -Luster: metallic -Cleavage: poor -Fracture: uneven -Tenacity: brittle**** (compared to Gold) -Soluble in nitric acid -Environment: Metallic sulfide vein deposits, disseminated copper deposits, contact metamorphic deposits, magnetic segregation deposits -Location: Cornwall, England, Ontario, Butte, Montana, Bingham, Utah, Jerome, Arizona. -Uses: Sulfide, important ore of copper. -Associated Minerals: pyrite, galena, sphalerite, chalcocite, malachite, quartz, calcite. -Alteration: to malachite and iron oxides Name: From Greek "chalkos", copper, and "pyrites", strike fire.

Tourmaline Group

-Distinguishing Characteristics: Crystals with rounded triangular cross sections. Very Poor cleavage distinguishes it from hornblende crystals. Beryl has a lower SG. -Na(Mg,Fe,Mn,Li,Al)3Al(Si6O18)(BO3)3(Oh,F)4 -Class: cyclosilicate -Crystal system: trigonal -Cleavage: none -Streak: white, black (schorl), blue (idicolite), pink and red (rubellite), brown (dravite), green, multicolored, rarely white -Hardness: 7-7 -SG: 2.9-3.3 -Transparent- Opaque -Fracture: conchoidal to uneven -Tenacity: brittle -Luster: vitreous -Alters to fluorite and kaolinite -Uses: semiprecious stone, black glassy varieties used to electrical apparatus which depends on thir pressure-electric (piezoelectricity) characteristic. -Environment: igneous and metamorphic rocks and veins, in granite pegmatites, regional metamorphic rocks, hypothermal veins, hydrothermal veins, hydrothermal replacement deposits

Diamond

-Distinguishing Characteristics: Distinguished from other colorless minerals like quartz, topaz, and corundum by superior hardness, octahedral crystals, brilliant refraction, dispersion when cut, and peculiar brilliant greasy luster when uncut (oiled class). -C (Class:native element) -Crystals: isometric, octahedral, cubic, dodecahedral -Twinning common -Fracture: conchoidal -Environment: alluvial desposits, sedimentary deposits -Forms deep within the earth with very high temperatures and pressures or in periodite of plutonic rocks -Hardness: 10****** -SG: 3.5 -Uses: abrasive, aggregates -Streak: none -Luster: adamantine, greasy***** -Cleavage: perfect -Fracture: conchoidal, brittle -Man made stones are fluorescent -Name: From Greek "adamas", 'invincible'. First known use by Manlius (A.D. 16) and Pliny (A.D. 100).

Hornblende

-Distinguishing Characteristics: Elongated blackish crystals and amphibole cleavage, distinguishable form tourmaline because tourmaline has very poor cleavage. -(Ca,Na)2-3 (MgFeAl)5(Si,Al)8 O22 (OH)2 -Class: inosilicate -Crystals: long or short primsatic -Crystal system: monoclinic -Twinning common -Cleavage: perfect in two directions -Fracture: uneven -Hardness: 5-6 -SG: 3-3.5 -Streak: colorless, green, brown, black -Luster: submetallic, vitreous, pearly, silky -Alteration: from pyroxene to chlorite, biotite, calcite, and epidote. -Environment: basic igneous rocks, contains high amount of titanium, stalactites -Location: NJ, embedded in calcite, St. Lawrence County, NY, Ontario. -Name: From an old German term meaning "horn" and "blind" or "to deceive," in allusion to it occurring in ore deposits but not yielding any metal.

Beryl

-Distinguishing Characteristics: The pegmatitic occurrence and six-sided outline are very characteristic (vertically striated, mottles appearance). Only likely to be confused with apatite (which is much softer and is fluorescent and is soluble in acid), with white, massive topaz (wholly infusable), and with quartz (decrepitates violently). -Be3Al2(Si6O18) -Streak: colorless -Hardness: 7.5-8 -Hexagonal, dihex, diphyramidal -SG: 2.6-2.9 -Fracture: uneven, to conchoidal -Cleavage: imperfect -Density: 2.63-2.9 -Occasionally fluorescent yellow, light blue, purple, pink, or red -Transparent to Translucent -Crystals: hexagonal, prismatic, often vertically striated -Associations: quartz, feldspar, tourmaline, mica, cassiterite, lepidolite. -Alteration: to kaolinite and muscovite. -Environment: granite pegmatites, metamorphosed mica schists and in igneous rhyolite deposits. High temperature thermal veins. -Uses: Chief ore of beryllium, gemstone, mineral specimens and ore of beryllium, atomic research. -Found in Pala pegmatite District, San Diego Co., California for morganite. Columbia for emeralds. Russia for heliodor, Austria, Comombia, Brazil, South Dakota, Madagascar. Name: Possibly from the Greek "beryllos" which referred to a number of blue-green stones in antiquity.

Barite

-Distinguishing Characteristics: High gravity is such a light-colored mineral! Distinguished from calcite by insolubility in acid, from feldspar by its softness, from celestite and anhydrite by the orange fluorescence after firing and the green flame coloration, from fluorite by its lack of typical fluorite fluorescence. Tabular crystals, cleavage. -BaSO4 -Sulfate -Streak: white -Luster: Vitreous to pearly -Colorless to to bluish, yellow, brown, reddish. -Luster: glassy. Sometimes fluorescent. -Cleavage: Basal, prismatic, fair side pinachoidal -Hardness: 2.5-3.5 -SG: 4.5 -Fracture: uneven -Crystal: Orthorhombric to rhombic bipyramidal, commonly in thin and tabular crystals. "Desert roses" also occur. -*Known for replacing other materials and substances -Tenacity: brittle -Transparent to opaque -High density -Associations: calcite, dolomite, fluorite, quartz, galena, and silver. -Environment: Sedimentary rocks and late gangue mineral in ore veins. Low-to-moderate temperature hyrothermal sulfide veins, replacement deposits of limestones and other sediments, hot spring deposits, cavities of basic igneous rocks, sedimentary iron and manganese deposits, petrifying mineral in some fossils. - Found in roses of a red-brown color and sandy texture near Norman, Oklahoma. Largest in Cumberland, needles in Romania. Massive in California, Georgia, Tennessee, Missouri, and Arkansas. -Uses: weighting agent in drilling muds, pigment in paints and as a weighted filler for paper and cloth, opaque to x-rays; if it is given to a patient as a drink or enema it can be used to image the shape of internal organs by x-ray. 100's of years ago in Italy, called "Bologna stone" because of phosphorescence. Name: Derived from Greek word for heavy

Malachite

-Distinguishing Characteristics: Intense green color, effercescence when dissolved in HCl establishes it as a carbonate. Also botryoidal habit. -Class: Malachite -Cu2(CO3)(OH)2 -SG: 3.9-4 -Hardness: 3.5-4 -Streak: light green -Luster: adamantine, silky, dull -Cleavage: perfect in one direction -Fracture: conchoidal, splintery -Translucent -Tenacity: brittle -Crystal system: monoclinic -Crystal habit: short or long prismatic, botryoidal. -Associated minerals: azurite, cuprite, limonite, copper. -Alteration: pseudomorphs of malachite after azurite. -Environment: Commonest and most stable ore of copper, always forms near surface as a result of the weathering of primary copper sulfides. Forms as fibrous crusts and masses, used in Russia for carving and mosaics (only hardest masses; varies in hardness considerably). -Locations: Russia, Africa, Copper Queen Mine at Brisbee, Arizona, Germany (crystals), SW US, frequently seen as green coating on top of buildings. Uses: ore of copper, decoration. -Name: Named in antiquity after the Greek μαλαχή, "mallows," in allusion to the green color of the leaves.

Bauxite

-Distinguishing Characteristics: Much like a clay, though a little harder. Sometimes in nodules with sparkling shrinkage cavities lined with tiny crystals. Pistolitic types easier to spot. -Al2O3+SiO2+TiO2+Fe2O3 -Class: Group of related oxides with water of hydration: HYDROXIDE -Mixture of gibbsite [Al(OH)3], boehmite [AlO(OH)], and diaspore (HALO2). In common mixture, crystals will be microscopic and indistinguishable. -Streak: white -Color white- often stained brown or red by iron oxidation -Hardness: 1-3 -Fracture: conchoidal, earthy -SG: 2-2.5 -Luster: dull, grainy -Cleavage: none -Crystals: Amorphous to microcrystalline. Usually massive, sometimes in little spherical brown masses in matrix (pistolitic), more often like a hard clay. -Environment: weathered surface deposits, warmer areas. -Use: Chief ore of aluminum. Secondary material derived from the leaching of solica from clay minerals under conditions of tropical weathering. -Found in Alabama and Georgia, Arkansas, Brazil, Guyanas, France, and Hungary. Name: After the locality at Baux (or Beaux), near St. Reny, Bouches-du-Rhône, France.

Epidote

-Distinguishing Characteristics: Pistachio-green color and one perfect cleavage.Tourmaline has no cleavage or color change when prism is rotated. -Ca2(Al, Fe)3(SiO4)3(OH) -Class: soro-silicate -Complex silicates of calcium and alumminum with water -Streak: colorless or gray -Crystals: long, slender prisms -Hardness: 6-7 -SG: 3.3 -Fracutre: regular -Luster: vitreous -Cleavage: perfect in one direction -Crystal structure: monoclinic, elongated, striated crystals. -Alteration: from saussurititization, also from olivine, hornblende, augite, biotite, and garnet. -Use: minor gemstone. -Environment: Fromed by metamorphism of calcium-rich igenous and sedimentary rocks. Associated with chlorite, albite, and actinolite in gneisses and schists. Also in contact-metamorphosed limestone; in pegmatite, in basalt cavities. -Typical mineral where igneous rocks have come in contact with limestones -Location: Austria, Wales, California (with garnet), Idaho (foot-long crystals) -Name: From the Greek "Epidosis" = "increase" in allusion to the crystal characteristic of one longer side at the base of the prism.

Bornite

-Distinguishing Characteristics: Purplish-iridescent tarnish, occurs with other copper sulfides and is an important ore of copper. "Peacock ore." Intergrown with chalcopyrite and chalcocite. -Cu5FeS4 -Streak: Dark gray to black -Hardness: 3 -Orthorhombic -SG: 4.9-5.3 -Luster: Metallic -Fracture: Conchoidal -Use: ore of copper. -Associated Minerals: copper minerals (chalcopyrite), pyrite, arsenopyrite, quartz. Alteration: to chalcopyrite, azurite, and malachite. -Environment: Disseminated in igneous intrusions and a primary and secondary mineral in copper ore veins. Pegmatites, contact metamorphic deposits, replacement deposits, also disseminated in basic rocks -Found in Cornwall, England and Arizona porphyry copper deposits, Connecticut, Mexico, Peru, Chile, Tasmania, Butte. -Name: Known since 1725, but not given its current name until 1845 when it was named for Ignaz von Born (1742-1791), Austrian mineralogist.

Almandine (Garnet)

-Distinguishing Characteristics: So generally crystallized and so typical. Red grains seen embedded in metamorphic and igneous rocks are most likely to be garnets. (Apatite is softer and does not melt, altered pyrite gives a limonite streak, zircons often fluoresce and will not fuse, short tourmalines can look like dodecahedrons, but will not fuse like a garnet). Insoluble in acids. -Fe3Al2(SiO4)3 -Silicate -Streak: White -Color: deep red, brownish red, purpley -Hardness: 7.5 - 8.5 -Crystals: Isometric, dodecahedral and trapezohedral -SG: 3.5 - 4.3 -Luster: Vitreous, resinous -Tenacity: Brittle --Transparant to Transluscent -Uses: Gemstone or abrasive -Found in Brazil, India, Madagascar, Sri Lanka and the United States. Smaller deposits exist in Austria and the Czech Republic. Almandine garnet star-stones are found in India and the United States (Idaho). Occurrence: Usually in metamorphic rocks such as mica schist, gneisses, pegmatite, included needle-like crystals of hornblende or augite produce a star effect in some almandine garnet. -Name: for Alabanda in Turkey, ancient gem-cutting center.

Staurolite

-Distinguishing Characteristics: Twinning, hardness -FeAl4S2O10(OH)2 -Class: nesosilicate -Streak: weathering to gray, white, yellowish brown, reddish to brownish, black -Hardness: 7-7.5 -SG: 3.7 -Crystal system: orthorhombic -Crystal habit: monoclinic, prismatic, twinned, pseudohexagonal cross section -When at 90 degrees they form a perfect cross -Found in Mineral Bluff, Georgia, Virginia, Switzerland -Fracture: conchoidal to uneven -Uses: good luck charms "fairy stones", transparent crystals cut into gems -Environment: gneiss and schist of regional metamorphic rocks -Luster: vitreous, dull -Cleavage: poor -Name: From Greek "stauros", cross, alluding to the cruciform twins it displays in some cases.

Lepidolite

-Distinguishing Characteristics: Usually associated with pink tourmaline. -K2Li3Al3(AlSi7O20)(OH,F)4 -Class: phyllosilicate -Uses: source of lithium -Found in New England, San Diego -Hardness: 2.5-3.5 -SG: 2.8-2.9 -Luster: subvitreous, reinous, pearly -Streak: white -Tenacity: elastic -Cleavage: perfect -Fracture: micaceous -Density: 2.8-2.9 -Crystal system: monoclinic, prismatic. -Environment: Uncommon,, found in lithium-bearing pegmatites, commonly associated with tourmaline, albite, muscovite, topaz, and quartz. Location: Maine, South Dakota, Connecticut, California, Brazil, Ural Mountains, Germany.

Olivine

-Distinguishing Characteristics: Usually identified by color and occurrence. No similar mineral of this hardness and color in likely to be encountered in the same environment. Apatite is usually fluorescent and softer; green tourmaline comes in granite pegmatites where olivine could not form. -(Mg, Fe)2SiO4 -Class: neso-silicate -Hardness: 6.5 -SG: 3.3 -Luster: glassy, vitreous -Transparent- Translucent -Crystals: RARE, usually embedded grains, commonly any free crystals that are founs will be altered to serpentine. -Fracture: small, conchoidal -Known as the "evening emerald" -Streak: colorless, yellowish green, yellowish brown, reddish -Crystal system: orthorhombic, rhombic bipyramidal. -Cleavage: indistinct in two directions at 90 degrees -Environment: Solid, granular masses found in basalt bombs in Arizona, and in Hawaiian lavas. Common rock-forming mineral of the darker rocks, never with free quartz. Common in meteorites. -Locations: NC, Arizona, Italy, Eifel, Norway, St. John's Island. Use: chief source of jewelry peridots (chrysolite variety)

Azurite

-Distinguishing Characteristics: color, association with green malachite, effervescence in acid (dissolved in HCl) -Cu3(CO3)2(OH)2 -Carbonate -Color: azure blue, blue, blue, other blues -Streak: Light blue -Hardness: 3.5-4 -Monoclinic -Tenacity: brittle -SG: 3.7-3.9 -Luster: Vitreous to Dull -Fracture: Conchoidal or Splintery -Cleavage: one good and two poor. -Tenacity: brittle. -Environment: Secondary mineral in the oxidized zone of copper ore deposits. Formed by oxidation and carbonation of other copper minerals. -Crystals: glassy, highly modified, tabular. Frequently altered to green malachite. -Found in Tsumeb near Otavi, Namibia, Chessy, France, Siberia, South Australia, Clifton and Brisbee, Arizona. -Use: very minor ore of copper, sometimes decoration. -Name: From the Persian lazhward, meaning "blue", in allusion to the color.

Kaolinite

-Distinguishing Characteristics: earthy odor when breathed upon. -Al2(Si2O5)(OH4) -Luster: waxy, pearly, dull, earthly -Translucent, opaque -Streak: white -Hardness: 2-2.5 -SG: 2.6 -Fracture: subconchoidal -Tenacity: sectile -Cleavage: perfect in one direction -Density: 2.63 -Crystal system: Triclinic -Found impure as clay, formed by weathering or by the hydrothermal alteration of feldpar in granite and pegmatite. -Uses: ceramics, source of metallic Al, filler in paper products -Name: Named for the ancient Chinese locality "Kaoling (Gaoling)", meaning high ridge.

Talc

-Distinguishing Characteristics: greasy feel, foliated structure, softness -Mg3Si4O10(OH)2 -Class: phyllosilicate -Uses: lubricate, talcum powder in cosmetics, as insulation in electrical equipment -Environment: hydrothermal alterations, regional and contact metamorphic rocks -Streak: white -Translucent to transparent -Sheets are flexible -Fracture: irregular -Hardness: 1 -SG: 2.58-2.83 -Luster: pearly, greasy -Found in NE, NC, England, Austria, France, India -Crystal system: monoclinic -Crystal habit: rare, usually foliated, grannular, fibrous -Massive talc called soapstone -Alteration: from olivine, amphiboles, and pyroxene -Name: From Arabic "talq", pure, probably alluding to the color of its powder.

Magnetite

-Distinguishing Characteristics: srong magnetism and black octahedral crystals. -Fe3O4 -Class: multiple oxide -Hardness: 6 -SG: 5.2 -Environment: basic igneous rocs and metamorphisized sedimentary rocks -Streak: black -Density: 5.2 -Fracture: uneven -Tenacity: brittle -Twinning: common -Crystal system: isometric -Some are naturally magnetized -Luster: metallic -Cleavage: none -Alteration: to hematite and limonite. -Use: important ore of iron, Can be used as a sorbent to remove arsenic from polluted water -Environment: Accessory mineral forming forming small grains in igenous rocks, after weathering black beach sands, concentrated by magmatic processes into solid ore deposits. In metamorphic rocks may form fine crystals, also found well-crystalized in pegmatites and high-temperature veins. -Location: Sweden, Ural Mountains, Adirondacks, Noway, Arkansas. Name: Magnesia, Greece (site for lodestone)

Silver

-Distinguishing Characteristics:No other white malleable metal soluble in acid is likely to be encountered -Class: native element -Luster: metallic -Environment: hydrothermal veins and oxidized silver, volcanic rocks -SG: 10.5 -Hardness: 2.5-3 -Fracture: hackly -Malleable and ductile -Soluble in nitric acid -Uses: silver ore, jewelry, utensils, pins -Streak: shiny silver-white to light lead grey, silver white, tarnish yellow, brown, black -Crystal System: isometric -Crystal habit: rare cubic octahedrons and dodecahedrons or in groups of parallel cubes -Cleavage: none -LocationL Mexico, Norway veins with calcite and sulfides, Canada with uranium ores, Michigan in pure masses with native copper (halfbreeds). -Not the most important source of cipper--commonly associated minerals are much more abundant. -Name: From Old English "seolfor", original meaning lost; The chemical element abbreviation Ag comes from the Latin word "argentum", meaning silver.

Native Copper

-Distinguishing Features: copper-red color, streak, malleability, sectility, and high specific gravity. -Cu -Hardness: 2.3-3 -Ductile, malleable, conductive -Fracture: jagged, hackly -Class: native element -SG: 8.9 -Streak: copper red -Luster: shiny, metallic -Cleavage: none -Crystals: isometric, hexoctahedra. Cubical, and dodecahedral, rarely octahedral, elognated, distorted Associations: malachite, azurite, chalcopyrite, boronite, gold, silver, calcite. Alteration: oxidizes to cuprite, malachite, and azurite. -Uses: electrical purposes, copper ore, pennies, pipes -Large deposits in Michigan, Montana, Tennesse, and SW -Environment: basalt of volcanic rocks and veins, disseminated hydrothermal replacement deposits -Found in Chile, Peru, Cyprus, Africa Name: From Greek "kyprios", of Cyprus, the location of ancient copper mines; Latin "cuprum".

Muscovite (Mica)

-Distinguishing characteristics: Colorless or pale thin flexible cleavage planes. -KAl2(AlSi3O10)(OH)2 -Class: phyllosilicate -Hardness: 2.5 -SG: 2.8 -Streak: white -Luster: vitreous, silky, pearly -Tenacity: elastic -Transparent to translucent -Cleavage: perfect in one direction -Crystal system: monoclinic, prismatic. Foliated masses. -Crystal habit: commonly tabular parallel to the cleavage, often hexagonal in outline -Density: 2.83 -SG: 2.7-3 -Associations: quartz, orthoclase, microcline, albite, topaz, tourmaline, beryl. -Uses: filler in various industrial products, insulator in electrical equipment, furnace linings. -Environment: Common rock-forming mineral in granites, syenites, pegmatites, schists, and gneisses. -Location: New Hampshire, NC, Black Hills of South Dakota, pink in NM, VA, MA, bright green (fuchsite) in NC and Utah. -Named after Muscovy where it was used as a substitute for glass

Apatite

-Distinguishing characteristics: Crystals resemble beryl, but can be distinguished by the hardness (can just be scratched by a knife!). Resembles green tourmaline, but is softer and is usually fluorescent. Often contains many small cracks, giving the crystals a shattered appearance. Edges sometimes appear to be partially dissolved. -Ca5(PO4)3(OH,F,Cl) -Phosphate -Uses: manufacture of fertilizer - it is a source of phosphorus, gemstone -Streak: White -Hardness: 5***** -Color: green, white, colorless, yellow, bluish, reddish, brown, gray, purple. -Luster: Vitreous to subresinous -SG: 3.1-3.2 -Hexagonal -Fracture: conchoidal -Cleavage: imperfect basal -Tenacity: brittle -Environment: As gemmy crystals in granite pegmatites; in hornfels in contact metamorphic rocks; in igneous diabase environments; in ore veins, and in nepheline syenite pegmatites. Igneous rocks and metamorphosed limestones, hydrothermal ore veins, bedded in marine deposits, component of fossils, guano deposits. -Common everywhere -Name: From the Greek απατείν ("apatein"), "to deceive" or "to be misleading", as Apatite was often confused with other minerals (e.g. Beryl, Milarite)

Biotite (Mica)

-Distinguishing characteristics: Distinguished from other micas by its dark colors, rare (Vesuvian) light phases, sulfuric acid reaction (forming milky solution on boiling in strong acid -K(Mg,Fe2+)3(Al,Fe3+)[(Al,Si)3O10](OH,F)2 -Streak: White -Hardness: 2.5-3 -Crystals: Monoclinic, prismatic. -SG: 2.8-3.4 -Luster: Pearly -Fracture: uneven -Cleavage: micaceous -Associations: quartz, muscovite, othorclase, amphiboles. -Alteration: to epidote. From amphiboles, pyroxenes, and garnet. -Environment: Biotite is a common rock-forming mineral, and is especially noted in metamorphic rocks such as schist and gneiss. It is also found in igneous rock such as granites and rhyolites. Biotite is also the primary mica in rare earth pegmatites. -Uses: surface treatment in decorative concrete, plaster and other construction materials, potassium-argon method of dating igneous rocks, insulation. -Location: Moscow, Russia, Mt. Vesuvius.

Amazonite (Microcline)

-Distinguishing characteristics: Hardness and cleavage when considered in relation to associated minerals. Schiller (iridescence) -K(AlSi3O8) -Silicate, feldspar (only bright green feldspar!) -Streak: White -Color: green to blue-green, color caused by elevated content of Pb. Can be decolorized by heating above 270° -Fracture: Conchoidal (irregular/uneven) -Hardness: 6-6.5 -Luster: Vitreous; pearly on cleavage surfaces. -Cleavage: good in two directions almost at right angles. -Tenacity: brittle -SG: 2.56-2.57 -Translucent to opaque -Crystal: triclinic; pinacoidal, large crystals common. Tabular or short, prismatic crystals. Frequently twinned. -Uses: Ceramics, jewelry, ornamental. -Alteration: to kaolinite. -Location: Norway, Colorado, Virginia, Brazil, India, Russia, Madagascar. Occurrence: Igneous rocks; pegmatites associated with quartz and albite as large crystals, cleavable masses. Also found in hydrothermal veins and areas of contact metamorphism. Name- From the greek μικρός (little) and κλινειν (to incline), in allusion to the small departure from monoclinic symmetry

Celestite

-Distinguishing characteristics: Light blue color, often only tints part of the otherwise white crystal. Softness and acid insolubility. Crystals, high specific gravity, associations with sulfur, tests for strontium and sulfur distinguish it from barite. -SrSO4 -Environment: Sedimentary rocks -Found in Kelley Island, Lake Erie -Streak: White -Hardness: 3-3.5 -Crystals: Orthorhombic, bipyramidal, commonly tabular and elongated -SG: 3.9-4.0 -Luster: Vitreous, pearly on cleavage sides -Cleavage: 1,1 - basal ; 2,1 - prismatic ; 3,1 - pinacoidal (like barite) -Fracture: uneven -Associated minerals: sulfur, gypsum, halite, fluorite, calcite, dolomite. -Occurrence: Sedimentary limestones, rarely in hydrothermal veins, cavities in basalt. Sedimentary deposits, bedded in deposits of gypsum, halite, and aragonite, commonly associated with sulfur, or in veins, cavities, and disseminations in limestones and dolomites, or in small amounts in evaporite deposits of potassium salts and borates, or disseminated in marl, shale, and sandstone. -ID: 1) Occasionally fluorescent in shortwave ultraviolet light. 2) Sometimes thermoluminescent

Rhodonite

-Distinguishing characteristics: Rose to pink color with black alterations, tabular crystals, and cleavage. -Mn(SiO3) -Class: inosilicate -Found in Franklin, NJ -Hardness: 5.5-6.5 -Translucent -Streak: white, colorless, brownish red, flesh-red, pink, rarely yellowish, or greenish, may tarnish brown or black upon exposure -Luster: vitreous -Crystal Habit: large flattened crystals -Crystal system: triclinic, pinachoidal -Cleavage: prismatic -Fracture: uneven -SG: 3.5 -Uses: ornamental and gem stone -Environment: In metamorphic rocks. Large crystals over 7 in long occur in calcite associated with zinc minerals at Franklin, NJ. Compact rose-colored masses with black alterations occur in the Ural Mountains. Also in Sweden, and Brazil. Name: From the Greek ρόδον, "rose", referring to its colour.

Halite

-Distinguishing characteristics: cubic crystals, cleavage, salty taste. -NaCl -Class: Halide -Tenacity: brittle -Streak: white -Luster: vitreouos -Cleavage: perfect in three directions at 90 degrees -Hardness: 2-2.5 -SG: 2.3 -Solube in water -Tenacity: flourscent, brittle -Crystal structure: cubic, often distorted with hopper-like depression in each cube face. -Fracture: conchoidal, uneven -Uses: chemical industry, reduce ice on highways, table salt. -Found in granular, fibrous, crystallinne masses. Dried lakes in arid climates, and sedimentary beds (evaporite deposits). Name: From the Greek άλς, sea, for halites, later modified by J.D. Dana to halite. -Random: Irregular patches of deep blue to violet color are believed to be caused by certain defects in the crystal structure that absorb light, due to excess of sodium ions, or colloidal sodium.

Sulfur

-Distinguishing characteristics: yellow color, ease of burning, low hadness, and low specific gravity. -Class: native element -Transparent to translucent -Sublimation of volcanic gases -Environment: sedimentary rocks -SG: 2.0-2.1 -Hardness: 1.5-2.5 -Fracture: uneven to conchoidal -Low melting point -Insoluble in H2O and hydrochloric acid -Soluble in carbon disulphide -Uses: manufacture of sulfuric acid, tips of matches and batteries -Environment: deposited as a direct sublimation product from volcanic gases, basalt of volcanic rocks -Streak: white, shade of yellow -Luster: resinous, adamantine -Crystal system: orthorhombic -Crystal habit: steep, bipyramids sometimes tabular also granular, fibrous, compact, earthy -Fracture: conchoidal -Cleavage: poor in two directions

Quartz (Citrine)

-Luster: glassy, vitreous, greasy -Yellowish to brown, less common than amethyst or smoky quartz. -On heating, becomes bleached, becomes smoky brown when irridates with x-rays. -most gem material sold as citrine is not natural citrine by heat-treated smoky or amethyst quartz. -yellow quartz is often sold as topaz but THAT'S NOT TRUE, DAMN IT! -Cleavage: rhombohedral -Dissipates negative energy -Rare natural occurence -Streak: white, clear yellow, red-orange, orange- brown -Crystal system: hexagonal

Quartz (Crystal)

-Most common -Often includes air bubbles and traces of other minerals -Sand -Found in Brazil, US, Swiss Alps, Himalayas, Peru, Mada -Streak: white, colorless, transparent -Luster: vitreous, glassy -Crystal system: hexagonal

Quartz (Amethyst)

-SiO2 - Ferric iron content large compared to smoky and colorless quartz: produces the color. Small amounts of Mn and Ti bear no relationship on color. -Same class, use, environment, hardness -Violet, reddish-violet, purple. Often distributed in patches or bands. Can be decolorized by heating to 290 degrees Celsius. Heating to 500-600 degrees can yield a citrine color. Can be made purple again by irridation with radium or x-rays. -phantoms of amethyst can sometimes occur in colorless quartz. -SG: 2.65 -Streak: white, purple -Luster: vitreous, greasy -Cleavage: none -Fracture: conchoidal -Crystal shape: tetrahedron/ hexagonal, moderate in size, usually not over 5 inches long. Fine polysyntheitc twinning striations on rhombohedral faces. -Commonly forms at relatively low temperatures in cavities with volcanic flows where it is associated with agate. -Brazil, Uruguay, Siberia, Nova Scotia, and Ontario.

Quartz (Agate)

-SiO2 -Class: tectosilicate -BANDING*** concentric following outline of cavity. -Same uses as other quartz -Same environment -Same SG and Hardness -Same luster -Streak: white, variegated, banded (agate), sard and carnelian (clear red to brownish red) in layers (sardonyx and onyx) -Commonly occurs as a cavity filling. -No crystals

Quartz (Chert/ Flint)

-SiO2 -Class: tectosilicate -Black, white, gray, or yellowish. -Environment: formed generally near the earth's surface where temperatures and pressures are relatively low, in the zone of alteration of lode and massive hydrothermal replacement deposits -SG: 2.6-2.64 -Hardness: 7 -Streak: white, whitish, dull, gray, smoky, brown to black -Luster: waxy, vitreous, dull -Crystal habit: occur as crusts showing botryoidal and mamillary forms. Miscroscopic grain, no definite banding or translucency, impurities. -Fracture: conchoidal -Opaque. -Brittle to tough

Quartz (Rose)

-pale pink to deep rose, caused by Mn3+ for Ti4+ ions. -massive varieties occurs in considerable amounts in pegmatites. -crystals rare and small, less than .5 in. -RARE and prized by collectors. -commonly contains microscopic needle-like inclusions of rutile, which have been precipitated from solid solutions. Star effect of asterated rose quartz caused by scattering of light from these needles. -becomes dark smoky gray to black when subjected to x-rays, bleaches when heated in ait to 575 degrees Celsius. -Index of Refraction: 1.544-1.553 -Crystal system: trigonal -Streak: white, pink, rose red -Luster: vitreous, greasy

Augite

Distinctive Characteristcs: prismatic crystals, cleavage, and light green color. Distinguish from amphibole by cleavage angles and from tourmaline by prismatic cleavage. -(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6 -Silicate, pyroxene group, diopside series -Streak: Light green to colorless -Color: brown-green, black, green-black, brown, purplish brown -Hardness: 5-6 -Monoclinic, prismatic with square or 8-sided cross sections. -SG: 3.2-3.6 -Luster: Vitreous, Resinous, Dull -Fracture: uneven, splintery -Cleavage: 87° and 93° -Alerations: to serpentine, talc, chlorite, epidote, hornblende. -Environment: Most widespread of the pyroxenes. An important constituent of many igneous rocks (darker plutonic), including basalt, diabase, and gabbro. Also in carbonatite and nepheline syenite pegmatites, and in metamorphic Serpentine deposits. -Common worldwide, but well-formed free crystals from volcanic rocks are not common: found at Mt. Vesuvius, German Eifel and in Bohemia, St. Lawrence County, NY, Renfrew County, Ontatio. -Uses: mineral specimens Name: by Abraham G. Werner in 1792 from the Greek αυγή ("auge") for "shine" or "luster," in allusion to the appearance of its cleavage surfaces

Calcite

Distinguishing Characteristics: Hardness, rhombohedral cleavage. Bubbles in acid distinguish it from all other minerals with prominent cleavages, even other carbonates. Aragonite dissolves easily, but has a different crystal form and no cleavage. Aragonite also crumbles when heated and loses fluorescence. Calcite, conversely, becomes fluorescent after heating. -CaCO3 -Environment: Found in sedimentary, igneous, and metamorphic rocks -Common Worldwide -Crystals: Hexagonal, scalenohedral, also short to long prisms, -Luster: Vitreous, Pearly -Uses: In cements and mortars, production of lime, limestone is used in the steel industry; glass industry, ornamental stone, chemical and optical uses and as mineral specimens, fertilizers. -Streak: White -Hardness: 3 -SG: 2.7 -Cleavage: 1,3 - rhombohedral -Fracture: conchoidal (Rarely observed bc of cleavage) -1) Commonly fluorescent; specimens from different localities fluoresce different colors. Some Calcite is also phosphorescent. 2) Transparent crystals exhibit strong double refraction. 3) May be thermoluminescent -Types: Iceland spar (colorless, transparent, strong double refraction), dog-tooth spar (acute scalenohedral crystals), satin spar (fibrous calcite with silky luster), sand (crystals containing up to 60% quartz sand), mexican onyx (banded calcite or aragonite), cave deposits (stalactites and stalagmites), travertine or tufa (deposits left by hot or cold calcareous springs, often porous), limestone; chalk (dull, compact rocks whose chief constituent may be calcite), marble (coarse or fine-grained metamorphic equivalent of limestone). -Possible confusions: aragonite (lacks rhombohedral cleavage and differs in crystallization), dolomite (only slightly soluble in cold HCl, curved, saddle-shaped aggregates are characteristic). Enviroment: Huge sedimentary deposits on ocean floors, marbles (or crystalline limestones), hydrothermal veins with sulfide ores, also as travertine deposits around hot and cold springs and steams. Mammoth Hot Springs and Yellowstone, Mammoth Cave in Kentucky, Luray caverns in Virginia, Carlsbad Caverns in New Mexico, Missouri, Kansas, Oklahoma, Michigan, Germany, Iceland, England, Mexico, California, Utah, Illinois, Ohio, NY, Pennsylvania, Indiana, Wisconsin. Name: From Calx, the Latin for Lime.

Fluorite

Distinguishing Characteristics: Perfect cleavage and hardness. Often fluorescent (blue) under ultraviolet light. Harder than calcite, commonly more attractively colored, and does not bubble when a drop of HCl is placed on it. Much softer than quartz. Powder does not dissolve in nitric acid as apatite's does. -CaF2 -Class: Halide -Environment: sedimentary and igneous rocks, contact metamorphic rocks, epithermal veins, and lode hydrothermal replacement deposits. Associated with calcite, dolomite, barite, quartz, galena, and sphalerite. In high-temperature veins, associated with cassiterite, wolframite, topaz, tourmaline, molybdenite, apatite, and quartz. In dolomites and limestones. -Found in Illinois, Kentucky, Colorado, and New Mexico. Germany, Russia, Canada, Italy, England, and France. -Uses: to produce a fluid slag in steel- making and in smelting ores, high test gasoline, hyrdofluoric acid, opal glass, fluorocarbon plastics and gases, crystals used for lenses, and spectrographic prisms that transmit ultraviolet light. -Hardness: 4 -SG: 3.2 -Streak: white -Fracutre: uneven -Luster: glassy -Cleavage: fine fragments, octahedral -Crystals: isometric -Chlorophane, a thermoluminescent variety of fluorite, phosphoresces bright green when heated. This is found in New Brunswick, Canada, and Trumbull, Connecticut. Name: From the Latin, fluere = "to flow" (for its use as a flux; melts easily). The term fluorescence is derived from fluorite, which will often markedly exhibit this effect. The element fluorine also derives its name from fluorite, a major source for the element.

Feldspar (Orthoclase Group)

Distinguishing Features: Crystal habit, blocky cleavage, and hardness. Common mineral; resembles many other silicates. Distinguished by blocky cleavage, lack of twin striations on the good cleavage face 90-degree cleavages. Also hardness and acid insolubility distinguish it from calcite. -KAlSi3O8 -Class: tecto-silicate -Luster: vitreous, dull -Usually opaque -Fracture: conchoidal, uneven -Crystal: monoclinic, prismatic -Crystals: blocky, tabular -Cleavage: perfect in 2 directions, right angle prisms -Hardness: 6 -SG: 2.53-2.56 -Streak: white -Twinning -Polymorphs: microcline (amazonite) -Alteration: to kaolinite -Found in Salzburg, Austria, Cornwall, England, NY, Vermont, Maine, NH, USA -Uses: Porcelain, enamel, glass, ceramics. -Environment: Important in rock-forming minerals in plutonic, volcanic and metamorphic rocks, occurs also in arkose sandstone, sometimes in pegmatites, but much less frequently than microcline. Name: From the Greek orthos - "right" and kalo - "I cleave" in allusion to the mineral's right angle of good cleavage.

Aragonite

Distinguishing Features: pseudohexagonal prisms and effervescence (blue, pink, yellow, or cream) in cold acid. Lack of conspicuous cleavage, crumbles more on heating than calcite and loses fluorescence. Clear specimens exhibit strong double refraction (inner fuzziness). -CaCO3 (dimorphous with calcite, but much less common and less stable) -Carbonate -Streak: White Color: white, colorless, or pale tints -Hardness: 3.5-4 -Crystals: Orthorhombic, commonly pseudohexagonal twinned crystals, single ones typically long, slender, and pointed. -SG: 2.9-3.0 -Luster: Vitreous, Dull -Cleavage: poor parallel to -Fracture: subconchoidal -Alteration: to calcite. -Environment: Low-temperature and formed at near-surface conditions. Sedimentary formations and evaporite deposits, hot spring deposits, hydrothermal ore veins, igneous traprock environments, sedimentary formations, metamorphic schists. -Location: needle-like specimens in Cumberland iron ore mines, Sicily, Aragon, Spain, Austria New Mexico, Mexico (coral-like branching growth called flos ferri) -Uses: minor constituent of limestone which is used in cement and in steel production, ornamental carvings and as mineral specimens. -Name: Named in 1797 for the type locality, the village of Molina de Aragón, Spain, and not the province of Aragón, a mistake made by several later writers. -Random: iridescent inner surfaces of shells (and pearls) are composed of aragonite secreted by mollusks.

Gypsum (Alabaster)

Distinguishing characteristics: Hardness of 2! Scratched by fingernail. -CaSO4 2H20 -Class: sulfate -Hardness: 1.5-2 -SG: 2.2-2.4 -Cleavage: perfect in one direction -Luster: pearly to subvitreous -Streak: white -Crystal: fine-grained massive**** -translucent -Associations: halite, calcite, dolomite, sulfur, aragonite, quartz. -Uses: decorative (vases), chimneys, artistic stone carving, plaster of Paris, retarder in Portland cement, fertilizer, flux in glass manufacturing. -Environment: Most common sulfate mineral. Chemical sedimentary sequences, forms gypsum desposits in beds, hydrothermal replacement deposits. -Found in Castellina, Tuscany, Italy, Derbyshire, England, Chihuahua, Mexico, Chile, Utah, NY, MI, CA, TX, New Mexico, Nova Scotia. Name: Named in antiquity from the Greek "gypsos," meaning plaster.

Albite (Plagioclase Group)

Distinguishing characteristics: Should show smooth cleavage surfaces too hard to scratch with a knife. Repeated twinning and many fine parallel lines on good cleavage faces. -NaAlSi3O8 -Feldspar Group (most abundant rock-forming minerals) -Color: white to grey, buish, greenish, reddish, may be chatoyant. Cleavage: 2 good at about 93° to 94° -Streak: White -Tenacity: brittle -Hardness: 6-6.5 -Triclinic (pinacoidal) -Transparent to Translucent -Luster: Vitreous to Pearly (Pearly on cleavages) -Fracture: Sunconchoidal to uneven -Specific Gravity: 2.6-2.63 -Soluble in hydrofloric acid -Present in granite, pegmatite, plutonic, and metamorphic rocks (hydrothermal and alpine veins). Formation: Low temperature, late mineral in pegmatites and forms thin blades (cleavelandite; common in US) and late growth in parallel position on microcline). -Found in Finnbo, Falun, Dalarna, Sweden. Bourg d'Oisans and Isere, France -Uses: ornamental stone, ceramics and mineral specimens Name: Latin, "albus"

Topaz

Distinguishing characteristics: hardness, crystals, basal cleavage, and relatively high specific gravity. -Al2(SiO4)(F,OH)2 -Class: Nesosilicate -Hardness: 8 -SG: 3.5 -Fracture: subconchoidal to uneven -Environment: high temp mineral and is generally found in igneous rocks and high temp veins. In granite pegmatites, rhyolite of volcanic rocks and massive hydrothermal replacement deposits -Streak: colorless, white, yellow, pink, bluish, greenish -Alters to kaolinite -Luster: vitreous -Crystal system: orthorhombic -Crystal habit: stubby to medium long prismatic crystals striated lengthwise -Name: Named after Topasos Island in the Red Sea. In antique times, the name was probably used for the gemstone that is now known as Peridot.