chapter 6 - rock identification study guide
gabbro
igneous, closely related to granite, dark in color, large reflective crystals, intrusive cooling
coal
sedimentary, can write with, glossy, black, burial, compaction
rock salt
sedimentary, halite, crystal form, semi translucent, evaporation
gypsum
sedimentary, light in color, white crusty powdery edges, chemical action
conglomerate
sedimentary, rounded fragments, cementation
coquina
sedimentary, shells stuck together, organic cementing
clay
sedimentary, beige/ crème, powder, weathering and erosion
scoria
igneous, dark in color, holey, extrusive cooling, mafic magma
basalt
igneous, dense, not shiny, black, little to no crystals, extrusive
diorite
igneous, intrusive cooling, large reflective black and white crystals
pumice
igneous, light in color, light density, holey, extrusive cooling, no crystals
tuff
igneous, powdery, white, flaky, buried as it cooled, compacted, extrusive cooling
rhyolite
igneous, salmon, few crystals, relative to granite, extrusive cooling, light in color
granite
igneous, speckled, light in color, large reflective crystals, intrusive cooling, cooks slowly
porphyry
igneous, the crystals shine, process was intrusive (crystals) and extrusively cooked, shiny white crystals, dull dark background
obsidian
igneous, volcanic glass, glassy, dark in color, instant cooling
sandstone
layering, rough/ gritty, cementation
slate
meta, foliated, low T, high P, red/ grey, smooth, semi shiny,
marble
meta, large crystals, white, low P, high T
gneiss
meta, light and dark stripes, foliated, crystals, high T, high P
quartzite
meta, salmon/ red spectrum, mostly red with some white, waxy, semi smooth, no foliation, low P, low T
schist
meta, shiny, large, reflective crystals, foliated, high T, high P
breccia
sedimentary, angular fragments
shale
solidified mud in rock form, layering/ layers, dark in color/ grey, smooth, cementation
