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64 Cards in this Set
- Front
- Back
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What is a mineral? |
A mineral is a solid, naturally occurring, inorganic substance with a characteristic chemical composition and an internal atomic arrangement that is fixed |
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Characteristics of a mineral |
1. Luster 2. Hardness 3. Cleavage 4. Fracture 5. Specific gravity 6. Magnetism 7. Taste 8. Odor 9. Feel 10. Reaction to acid 11. Color |
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-Non-Silicate -Prominent Streak -Streak has a fetid smell and is pale yellow to brown; prominent cleavage in three directions. Resinous luster. H=3.5, G=4. May be massive or form equant crystals |
Sphalerite |
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-Non-Silicate -Prominent Streak -Lead grey streak and color -Metallic luster -Perfect cleavage in three directions -H=2.5, G=7.6 |
Galena |
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-Non-Silicate -Prominent Streak -Dark black streak and color, sooty, with shiny metallic luster -Perfect cleavage in one direction -H=1, G=2.2 -May be massive or occur as platy crystals |
Graphite |
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-Non-Silicate -Prominent Streak -Black to dark brown streak and color. -Usually magnetic -H=6, G=5.2 |
Magnetite |
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-Non-Silicate -Prominent Streak -Deep red to reddish brown streak -Color varies from reddish brown to grey or black -Luster is dull metallic -H=5.5-6.5, G=5.3 |
Hematite |
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-Non-Silicate -Prominent Streak - Brown to yellow-brown streak and color - Earthy, non-metallic luster - Generally massive or forming fine crystals -H=4-6, G=2.7-4.3 |
Limonite |
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-Non-Silicate
-Prominent Streak -Green-brown to black streak -Pale yellow to brass yellow color -Crystals often form cubes and pyretohedrons (with each face as a pentagon) -Conchoidal to irregular fracture |
Pyrite |
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-Non-Silicate
-Prominent Streak -Greenish black streak -Brass yellow -Metallic luster that tarnishes to brown and purple -Usually massive -H=3.5-4, G=4.2 |
Chalcopyrite |
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-Non-Silicate -Prominent Streak -Grey to black streak -Bronze-yellow color -Metallic luster that may have a reddish or brown cast -Commonly magnetic -Usually massive -H=3.5-4.5, G=4.6 |
Pyrrhotite |
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-Non-Silicate -Inconspicuous Streak -Perfect rhombohedral cleavage -Streak may be colorless to light yellow or brown -Mineral may be transparent, white, or yellow to pink, red or brown -Effervesces readily in cold, dilute HCL -H=3, G=2.7 |
Calcite |
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-Non-Silicate
-Inconspicuous Streak -Perfect rhombohedral cleavage, and commonly as rhombohedral crystals -Streak and mineral color may be colorless to light yellow, pink or brown -Effervesces in cold HCL only when powdered -H=3, G=2.8 |
Dolomite |
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-Non-Silicate
-Inconspicuous Streak -Perfect cleavage in three directions -Commonly forms octahedral fragments -Specimens may be colorless, purple, white, or green -H=4, G=3.2 |
Fluorite |
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-Non-Silicate -Inconspicuous Streak -Transparent crystals are common, but may be white, red, or blue -Perfect cleavage in three directions, 90 degrees apart, forming cubic fragments -Salty taste -H=2, G=2.2 |
Halite |
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-Non-Silicate
-Inconspicuous Streak -Transparent to white crystals -Perfect cleavage in one direction -Crystal forms vary considerably, and are commonly platy, bladed or prismatic -H=2, G=2.3 |
Gypsum |
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-Silicate -Perfect cleavage in one direction -H=2.5 on cleavage surfaces -H=4 at a right angle -G=2.8 -Crystals have a platy habbit -Individual plates tend to be elastic -Crystals are often clear and light grey to silvery, and may be tan or light brown |
Muscovite |
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-Silicate -Perfect cleavage in one direction -G=2.9 -Crystals tend to occur with a platy habit -Individual plates tend to be brittle -Crystals are often deep brown, and may be reddish brown to black -MG-rich varieties are colorless |
Biotite |
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-Silicate -Platy habit is common -H=1, G=2.7 -Masses of crystals have a soapy, smooth feel -Crystals are commonly white to clear, and may be light green |
Talc |
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-Silicate -Crystals usually are smaller than mm-scale to microscopic -Crystals occur in white, chalky masses -Earthy odor when damp -H=2.3, G=2.6 |
Kaolinite |
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-Silicate -Prominent cleavage in two directions that are close to 90 degrees apart -H=6, G=2.6 -May be clear, white, tan, pink, red, or brown -Crystals may contain thin layers of lightly colored plagioclase |
Orthoclase (Feldspar) |
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-Silicate -Prominent cleavage in two directions that are close to 90 degrees apart -H=6, G=2.6 -May be clear white or grey -One cleavage plane may show thin parallel striations |
Plagioclase (Feldspar) |
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-Silicate -Perfect cleavage in one direction -Commonly has a bladed habit -H= 5 along crystals -H=7 across crystals -G=3.5 -May be colorless, grey, or blue |
Kyanite |
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-Silicate -Prominent cleavage in two directions that are close to 90 degrees apart -Common chemical varieties are dark green to black -H=6.5, G=3.3 |
Augite (Pyroxene) |
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-Silicate -Prominent cleavage in two directions that are close to 60 or 120 degrees apart -Common chemical varieties are dark green to black -H=6, G=3.3 |
Hornblende (Amphibole) |
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-Silicate -Conchoidal fracture -H=7, G=2.65 -Crystals are hexagonal with prism and pyramid forms common -May be clear and colorless, white, smoky, purple, yellow-brown |
Quartz |
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-Silicate -Irregular fracture -H=7, G=4 -Commonly deep red, but may be purple, green, black, or white -Crystals are commonly equant with dodecahedron forms |
Garnet |
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-Silicate -Irregular fracture -Earthy luster when weathered -H=7, G=3.7 -Crystal faces display prominent 90 degree angles and twinned crystals are common -Typically deep red brown to brown in color |
Staurolite |
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-Silicate -Irregular to concoidal fracture in large crystals -H=6.5, G=3.3 -May be cm-scale single crystals or sugary masses of small crystals -Typically bright green and may show shades of brown to yellow |
Olivine |
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-Pyroclastic (fragments greater than 2mm) |
Volcanic Breccia |
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-Phaneritic (coarse-grained) -Felsic |
Granite |
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-Aphanitic (fine-grained) -Felsic |
Rhyolite |
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-Aphanitic (fine-grained) -Ultramafic |
Komatiite |
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-Phaneritic (coarse-grained) -Mafic |
Gabbro |
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-Aphanitic (fine-grained) -Mafic |
Basalt |
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-Glassy (compact glass) -Mafic |
Obsidian |
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-Aphanitic (fine-grained) -Intermediate |
Andesite |
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Whenever there are appreciable phenocrysts "porphyritic" precedes the name |
Porphyritic + Anything |
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-Pyroclastic (fragments less than 2 mm) -Felsic |
Tuff |
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-Phaneritic (coarse-grained) -Intermediate |
Diorite |
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-Phaneritic (coarse-grained) -Ultramafic |
Peridotite |
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-Vesicular -Felsic |
Pumice |
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-Detrital -fragments larger than 2mm -Angular rock or mineral fragments embedded in a matrix of finer material -color variable, various shades of grays, greens, reds, or browns |
Breccia |
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-Detrital -fragments larger than 2 mm -Rounded, smooth pebbles and cobbles embedded in a fine-grained matrix -color range similar to breccia |
Conglomerate |
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-Detrital -fragments 1/16-2mm -Angular feldspar grains make up at least 25% of rock -Feldspar and quartz commonly impart a light grey to pink or light red color to rock |
Arkose Sandstone |
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-Detrital -fragments 1/16-2 mm -Primarily rock and mineral fragments with varying amounts of clay -grains may be angular or rounded -fossil fragments common - may show stratification |
Greywacke Sandstone |
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-Detrital -fragments 1/16-2 mm -Primarily quartz grains -fragments may be angular or rounded -surface feels "sandpapery" -may or may not show bedding |
Quartz Sandstone |
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-fragments 1/256-1/16 mm -Minerals too small to be seen with unaided eye -should feel gritty on teeth -quartz and clay minerals predominate -commonly shows bedding |
Siltstone |
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-Detrital -fragments smaller than 1/256 mm -Minerals too small to be seen with unaided eye -cannot be felt abrading teeth -color variable -bedding not obvious -usually soft |
Claystone |
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-Detrital -fragments smaller than 1/256 mm -Minerals too small to be seen with unaided eye -cannot be felt abrading teeth -color variable -bedding reflected by thin laminae -usually soft |
Shale |
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-Chemical -Effervesces freely in dilute HCL -may contain fossils or small spherical sand-sized grains (ooliths) -may be visibly crystalline or microcrystalline -color white, grey, tan, or black |
Limestone |
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-Chemical -Consists of ground up shell material which is loosely cemented together |
Coquina |
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-Organic -Consists of microscopic shells of planktonic organisms -earthy, soft -color usually white |
Chalk |
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-Chemical -Effervesces weakly in HCL -may contain fossils -resembles various forms of limestone -color usually tan due to presence of some iron |
Dolostone |
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-Chemical -Hard -breaks with conchoidal fracture -dense -crystalline structure not visible to unaided eye -color variable |
Chert |
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-Chemical -Often soft enough to be scatched by fingernail -usually lacks bedding -color white, pink, or light red |
Rock Gypsum |
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-Chemical -Salty taste -feels greasy -color white to gray |
Rock Salt |
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-Organic -Black -Soft -Often brittle -leaves hands dirty |
Bituminous Coal |
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-Foliated -Very fine-grained -usually splits into sheets -color usually dark |
Slate |
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-Foliated -Fine-grained -silky sheen -wavy foliation common -may have porphyroblasts |
Phyllite |
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-Foliated -Coarse-grained -closely spaced oriented nonequidimensional minerals predominate |
Schist |
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-Foliated -Coarse-grained -minerals segregated so as to impart a banded texture to rock |
Gneiss |
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-Nonfoliated -Granular -Sharp edges -breaks with conchoidal fracture |
Quartzite |
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-Nonfoliated -Crystalline -Sugary appearence -effervesces in acid -light colors -H=3 |
Marble |
