Igneous
formed by magma
,
for example when a volcano erupts and the lava cools down igneous rocks are formed.
Metamorphic
formed by heat or pressure
,
for example when an rock is pressurized or heated and a metamorphic rock is formed.
sedimentary
formed by compacted or cemented together.
,
for example when you mix compacted and then cement you get a sedimentary rock
both formed by heat,
both contain crystal and gems
both made from he earth,
both occur from natural processes
both are made from pressure,
both are made from old rocks
rock,
minerals
