Rocks and the Rock
Cycle
• Rock is a solid material
made up of minerals or
other substances.
• Most of Earth’s rocks are
made up of about 20
common minerals, called
rock-forming minerals.
• The color of the rock depends
on the color of the minerals that
make up the rock.
• To a geologist, texture refers to
the size, shape, and arrangement
of a rock’s grains.
A rock grain is one of the particles
that make up a rock
• Geologists classify rocks into
three major groups by how they
are formed.
•Igneous rock
forms when lava
or magma cools
and hardens.
•Igneous rock formed
from magma beneath
the Earth’s surface is
called intrusive.
Intrusive – Inside the Earth
•Igneous rock formed
from lava above the
Earth’s surface is called
extrusive.
Extrusive – Exited the Earth
•Sedimentary rock
forms when
particles of rock
and other material
are pressed and
stuck together.
•Compaction
(pressed)
•Cementation
(stuck)
•Any rock can become
Sedimentary Rock
•There are three major
kinds of sedimentary
rock
Clastic – Organic – Chemical
• A sedimentary rock that
you can see the particles
of rock that have been
stuck together is called a
clastic rock.
• A sedimentary rock that
formed from the remains
of plants and animals is
called organic rock.
• A sedimentary rock that
forms when dissolved
minerals come out of
solution is called a
chemical rock.
•Metamorphic rock
forms from high heat
and pressure beneath
the surface of the
Earth.
•Any type of rock can
become a metamorphic
rock.
•The rock cycle is a
series of processes
that change rocks
from one kind to
another kind.
Explain the Rock Cycle
Begins
sedimentary
metamorphic
igneous
metamorphic
sedimentary
sedimentary
How It Changes
Ends