Rocks
Igneous
Comes from magma
or lava (volcanoes)
Sedimentary
Weathering – process of breaking down rock
Erosion – rock fragments are carried away by
water, wind or ice
Deposition – sediment settles out of the
water/wind into new locations
Compaction – process of pressing sediment
together
Cementation – dissolved minerals crystallize and
glue sediment particles together
Clastic – forms when
Intrusive – formed
when magma
hardens beneath the
Earth’s surface
Ex: granite
Extrusive – formed
from lava that erupts
onto Earth’s
surface
Ex: basalt
rock fragments are
squeezed together
Ex: conglomerate,
sandstone
Metamorphic
Forms from another rock
as a result of changes in
heat or pressure
Organic – forms where the
remains of plants and
animals are deposited in
layers
Ex: coal, limestone
e
Chemical – forms when
minerals dissolved in a water
solution crystallize
Ex: rock salt
Non-foliated – Grains
are arranged randomly
Ex: marble, quartzite
Foliated – Grains are
arranged in parallel
layers or bands
Ex: slate