Geology - Rock Classification

16 cards·by tiffreja

classificationidentifyingrocksidentificationgeologyscienceclassifying

Non-foliated-->translucent/pale-->fused quartz grains

quartzite

Non-foliated-->dark/dull/opaque-->dense, compact conchoidal fracture

hornfels

Foliated-->course grained/schistose/banded-->schistose, quarts/feldspar/mica completely mixed

schist

Foliated-->course grained/schistose/banded-->banded into light and dark

gneiss

Foliated-->fine grained/slatey cleavage-->gray/black/green/red, dull luster, rings when struck-->slatey cleavage into flat sheets

slate

Foliated-->fine grained/slatey cleaveage-->green, shiny luster, crystals may be visible-->slately cleavage to weak schistosity

phyllite

Reacts with HCI-->granular, translucent, many colors-->reacts without powdering

limestone marble

Reacts with HCI-->granular, translucent, many colors-->must be powdered to react

dolomitic marble

Luster

the dull or shiny surface appearance of a rock

Opaque

solid color, not see through

Schistosity

how much a rock is able to be split into thin layers because its micaceous minerals have become aligned in thin parallel bands

Metamorphic rocks

form when a sedimentary or igneous rock is exposed to high pressure, temperature, or both, deep below the surface of the Earth

Sedimentary rocks

form from material that has accumulated on the Earth's surface (such as shells in the ocean)

Igneous rocks

form by crystallization from molten or partially molten material (magma); include intrusive and extrusive

Intrusive igneous rocks

called plutonic rocks; form from magma that cools and crystallizes beneath the Earth's surface

Extrusive igneous rocks

called volcanic rocks; form from magma that cools and crystallizes on top of the Earth's surface