Term
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Definition
Metamorphic Rock
Schist
Foliated, medium to coarse grained
foliation formed by alignment of visible crystals; rock breaks along scaly foliation surfaces; crystalline texture
visible sparkling crystals of platy minerals (chlorite, biotite, muscovite) bladed crystals, prismatic crystals
Parent rock: mudstone, shale, slate, phllite |
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Term
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Definition
Metamorphic Rock
Serpentein
Nonfoliated -fine grained or no visible grains
microcrystaline texture or no visible grains
may have fibrous asbestos form
dull or glossy - color shades of green
Parent rock: basalt, gabbro, ultramafic igneous rocks |
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Term
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Definition
Metamorphic Rock
Gneiss
Foliated -medium to coarse grained
Gneissic banding; minerals segregated into alternating layers gives the rock a banded texture in side view, crystalline texture
Visible crystals of two or more minerals in alternating light and dark foliated layers
Parent rock: mudstone, shale, slate, phyllite, schist, granite, or diorite |
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Term
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Definition
Metamorphic rock
Slate
Foliated
fine grained or no visible grains
flat slaty cleavage is well developed
Dull luster breaks into hard flat sheets along the slaty cleavage
Parent rock: mudstone or shale |
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Term
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Definition
Metamorphic rock
Marble
Nonfoliated
fine to coarse grained
microcrystalline - like sugar cube
calcite (or dolomite) crystals of nearly equal size and tightly fused together
calcite effervesces in dilute hcl
dolomite effervesces only if powdered
Parent rock: Limestone |
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Term
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Definition
Metamorphic rock
Quartzite
Non foliated
fine to coarse grained
sandy texture
quartz sand grains fused together; grains will not rub off like sandstone, usually light colored
Parent rock: Sandstone |
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Term
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Definition
Metamorphic rock
Phyllite
Foliated
fine grained or no visible grains
breaks along wrinkled or wavy foliation surfaces with shiny metallic luster
Parent rock: mudstone, shale, or slate. |
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