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