small colour crystals lava rock Rocks large materials minerals cools lava
are
clusters
of
and
other
inorganic
.
Minerals
are
structured
that
have
specific
chemical
components
.
Igneous
rocks
form
when
molten
from
volcanoes
cools
down
.
If
the
cools
quickly
,
crystals
form
and
the
rock
has
dots
of
.
If
the
lava
slowly
,
crystals
form
and
the
looks
the
same
colour
all
over
.
Sedimentary
rocks
and
fossils
compact
over
millions
of
years
.
Metamorphic
rocks
form
when
igneous
and
sedimentary
rocks
are
pushed
down
by
other
layers
of
rock
from
above
.