th
4
Grade Earth
Science Review
The Rock
Cycle
Igneous Rocks


Igneous rocks can
form inside the earth
or outside the earth by
cooling magma or lava
Characteristics:
Usually have solid
colors or similar
speckles of quartz
throughout
Metamorphic
Rocks


Metamorphic rocks
are formed when
igneous or
sedimentary rocks
come under extreme
heat or pressure
Characteristic: Often
have unique curves or
designs
Sedimentary Rocks


Sedimentary rocks are
rocks that have been
broken off of igneous
or metamorphic rocks
through weathering
Characteristics:
smaller broken up
pieces of rock or sand
sometimes pressed
together
Volcanic activity forming igneous
rocks
Minerals

A mineral is a naturally
occurring, inorganic
solid with a definite
chemical composition
and a specific
crystalline structure
How to Classify a Mineral





Hardness
Color
Luster
Streak
Cleavage
Quartz
Calcite
Feldspar
Mica
Hornblende