Igneous Rock Chart (these are but a few of the many igneous rocks on Earth)
Igneous
Type
Intrusive
Texture
coarsegrained
finegrained
Extrusive
glassy
Cooling Rate
slow
deep
underground
fast
at the
surface
very fast
at the
surface
Light Color
(Felsic High SiO2)
Intermediate
Dark (Mafic low SiO2, high
Fe)
GRANITE
DIORITE
GABBRO
Very low
SiO2, very
high Fe
Ultramafic
(many kinds)
RHYOLITE
ANDESITE
BASALT
KOMATIITE
OBSIDIAN, PUMICE
Basaltic glass
Sedimentary Rock Chart (these are but a few of Earth’s sedimentary rocks)
Texture/Composition
Energy
Depositional Environment
Detrital (or clastic) Sedimentary Rocks
high
river channel, turbulent beach
high
alluvial fan
medium
beach, desert, sand bar
deep ocean, marsh, delta,
low
flood plain
Chemical Sedimentary Rocks
low to
warm shallow seas
medium
Rock Name
quartz
low
deep oceans
CHERT
gypsum or halite
very low
Evaporating ocean basin
EVAPORITE
very low
swamps
COAL
pebbles and sand
pebbles and sand (angular)
sand
silt and clay (mud)
calcite
CONGLOMERATE
BRECCIA
SANDSTONE
SHALE
LIMESTONE
Metamorphic Rock Chart (these are but a few of Earth’s metamorphic rocks)
Parent
shale
basalt
limestone
sandstone
Texture
foliated, smooth and
fine-grained
Composition
no minerals visible
usually gray
foliated, medium- to
coarse-grained
micas visible
garnet possible
foliated (banded),
medium- to coarsegrained
non-foliated, finegrained
non-foliated, fine- to
coarse-grained
non-foliated, usually
fine-grained
feldspar, black mica,
and quartz arranged in
bands
no minerals visible
greenish color
calcite (will fizz)
quartz (will scratch
glass)
Pressure
Rock Name
low
SLATE
medium
SCHIST
high
GNEISS
(may also form
from granite)
low
GREENSTONE
not
known
not
known
MARBLE
QUARTZITE