Geology rock and mineral identification

granite

igneous - felsic - phaneretic, intrusive -Has K-feldspar, quartz and some muscovite

rhyolite

igneous - felsic, can be porphyritic - black sprinkles -has K Feldspar and quarts, some muscovite

obsidian

igneous - felsic, glassy texture -extrusive origin - shiny

diorite

igneous - intermediate - Phaneritic, course grained -plagioclase feldspar, amphibole, biotiite, some quartz

andesite porphyry

igneous - intermediate composition - aphantic texture ot porphyritic(lab sample is porphyritic) has phenocrysts in an aphanitic groundmass - gray with phenocrysts

gabbro

igneous - mafic - phaneretic, intrusive -coarse-grained - black, shiny with crystals

scoria

igneous - mafic - vesicular texture, extrusive - brown in color, or red

basalt

igneous - mafic, extrusive -aphanitic, fine grained - pyroxine, olivine, some amphibole, some plagioclase feldspar

basalt porphyry

igneous - mafic, microscopic crystals - porphyritic - black

peridotite

igneous - phanerectic, intrusive - ultramafic - mostly olivine some pyroxene

sedimentary rock

rocks whos origin is from the 1. erosion, transportation, deposition, and subsequent lithification of pre-existing rocks. 2. organic or inorganic chemical reactions 3. lithified accumulations of organic debri

breccia

sedimentary - clastic texture - angular rock fragments stuck together

conglomerate

sedimentary - clastic texture - round rock fragments stuck together

bituminous coals

sedimentary - crystalline texture - organic materials, usually shiny - but this one is dull, not as shiny as anthracite coal -biochemical

shale

sedimentary - red colored - detrital/clastic texture - fragments not visible to the eye - contains mostly clay

coquina

sedimentary - shells fragmented together -biochemical limestone - carbonate composition

fossiliferous limestone

sedimentary - visible fossils - carbonate composition -Biochemical (fragments or shells of organisms)

chert

sedimentary -chemical/inorganic - crystalline, grey, brown, black - containing silica - silicious composition, may contain fossils -harder than glass, conchoidal fracture

mineral

1. naturally occuring 2. inorganic 3. solid 4. formed by geological processes 5. fixed chemical composition 6. definite crystalline structure

Dolostone

Sedimentary Rock -Fizz if powdered and pour HCL -chemical -usually light colored

Chalk

Sedimentary Rock -biochemical -silty, earthy rock composed of microscopic shells, may contain few visible fossils

Oolitic Limestone

Sedimentary Rock -chemical -comprised of spherical grains that resemble miniature pearls -limestone

Rock Gypsum

Sedimentary Rock -chemical -grey, white or colorless -can be scratched with your fingernail -mostly comprised of gypsum mineral crystals

Quartz Sandstone

Sedimentary Rock -medium grained clastic

clastic

aggregate of mineral grains or rock particles, or fragments of organic remains - conglomerate, breccia, quartz sandstone, arkose, siltstone, and shale

crystalline

composed of interlocking crystals - limestone, micrite, coquina, chert, and bituminous coal

pumice

igneous - vesicular -extrusive - small vessles - floats, light - gray

slate

metamorphic - foliated - dull luster

gneiss

metamorphic - foliated, medium to coarse grained - different layering (colors) -high grade -Parent rocks mudstone, shale, slate, phyllite, schist, or felsic to intermediate rock...granite or diorite

marble

metamorphic - non foliated - carbonate composition -parent rock limestone, will fizz with HCL, no powdering necessary -calcite or dolomite crystals

anthracite coal

metamorphic - non foliated - organic materials -protoliths are peat, lignite, bituminous coal

quartzite

metamorphic - non-foliated - quartz composition -protolith quartz sandstone

quartz

mineral - conchoidal fractures, harder than glass - colorless, almost transparent - can be black, with white areas - can be pink - NOT METALLIC - silicate

olivine

mineral - green - scratches glass - conchoidal fractures - harder than glass - not metallic, darker in color - silicate rock

magnetite

mineral - metallic, black in color - harder than glass - HARD - no cleavage - magnetic

pyrite

mineral - metallic, gold coloring - harder than glass - fools gold - no cleavage

galena

mineral - metallic, shiny colring - diamond looking things on side - harder than penny, softer than glass - cleavage in 3 directions, at 90

graphite

mineral - metallic, with a silver looking coating - cleavage in one direction or none - softer than fingernail - you can write with it, dark grey streak

amphibole

mineral - non metallic - cleavage in 2 directions, nearly 160 and 120 degrees -harder than glass - silicate minerals - silicate rock

gypsum

mineral - softer than fingernail, - cleavage goes in one direction - flat sheet - non metallic, transparent in color - slab - Stronger than talc, weaker than calcite

calcite

mineral - softer than glass - somewhat clear, but not transparent - non metallic, white yellowish in color - cleavage in 3 directions, not 90 degree (75 degrees, rhombus like) - softer than glass but harder than fingernail -efferveces with HCL

metamorphic rock

rock whose origin is from physical or chemical change of pre-existing rocks, by exposing them to 1. higher temperature 2. change of temperature 3. passage of fluids

igneous rock

rocks whose origin is from the cooling and subsequent crystallization of magma

siltstone

sedimentary - clastic texture - silt sized particles - looks like clay

sandstone

sedimentary - clastic texture - small sized sand particles put together

micrite (limestone)

sedimentary - conchoidal fractures - will fizz with HCL -biochemical

Chlorite

-Mineral -non-metallic -dark-colored blackish green -softer than your fingernail -one direction of cleavage -cleavage flakes are flexible but not elastic

Tuff

Igneous Rock -pyroclastic or fragmental

Hornfels

Metamorphic Rock -nonfoliated -usually a dull dark color -protolith- any rock type -fine grained or no visible grains, clay like

Vesicular basalt

-Igneous Rock -Mafic -Vesicular, extrusive -black, dark gray -has olivine, pyroxene, amphibole, plagioclase feldspar

Amphibolite

-Metamorphic -foliated or nonfoliated -parent rock Basalt, gabbro or uttramafic igneous rocks -mostly visible crystals of amphibole

Augite (Pyroxene)

-Mineral -Greenish black to black -harder than glass -2 directions of cleavage at nearly 90 degrees -non-metallic

limonite

-Mineral -Metallic -softer than glass but harder than finger-nail -yellow brown to dark brown -earthy appearance, yellow/brown streak

Garnet

-Mineral -Non-metallic -harder than glass -glassy luster -red to reddish brown -conchoidal fracture

Anorthite (CA Plagioclase)

-Mineral -gray -harder than glass -2 directions of cleavage at nearly right angles

staurolite

-Mineral -non-metallic -dark colored -harder than glass -cleavage present

Dolomite

-Mineral non-metallic -light colored -softer than glass but harder than your fingernail -may or may not fizz if powdered -grey, white, pink -3 directions of cleavage not at 90 degrees

Soapstone

-Non-foliated -talc can be scratched with your fingernail -shades of green, grey, brown -protolith is basalt, gabbro or ultramafic igneous rocks -fine grained

Arkose

-Sedimentary Rock -red, medium grained clastic -sandstone, mostly feldspar -detrital

phyllite

metamorphic -low to medium grade - foliated - black with some colors - black, shiny metallic luster, can be green and pearly -parent rock...mudstone, shale, slate

schist

metamorphic - foliated -medium to high grade - sparkles a little - black and white -protolith is mudstone, shale, slate, phyllite

kaolinite

mineral - chalky, soft - softer than finger - no cleavage - sticks to tongue -earthy odor

Pyroxene/Augite

mineral - cleavage in 2 directions, nearly at 90 - slightly elongated crystal - not metallic, darker in color Greenish black to black - harder than glass - silicate rock

halite

mineral - cleavage in 3 directions, 90 degree - not metallic, transparent in color - softer than glass but harder than fingernail - cube shaped - salt

orthoclase (K-feldspar)

mineral - non metallic, with a light color - pale pink, with some orange - 2 demensional 90 degree cleavage - harder than glass

talc

mineral - not metallic (earthy), light in color, pearly luster - white, pink, green - softer (mineral) than fingernail - 1 plane of cleavage but cleavage not prominent

biotite mica

mineral - not metallic, darker in color - softer than a fingernail - has clevage in one direction - greenish - brown - thin sheets - silicate

Sodium plagioclase feldspar (albite)

mineral - not metallic, light in color - pale, off white color - cleavage in 2 directions, at 90 - markings on the face - harder than glass - silicate

muscovite

mineral - not metallic, light in color - transparent thin sheets - cleavage in one direction - silicate

hematite

mineral - reddish with black spots - harder than glass - metallic, specular hematite is metallic - no cleavage