IGNEOUS ROCKS
(Igneous means FIRE)
Rocks that have solidified from magma or lava
Key Words:
Melting and Solidification
Intrusive: These igneous rocks form from magma under
the surface of the earth. They cool slowly which allows
large crystals to grow. Intrusive igneous rocks are often
coarse in texture because of the larger crystal formation.
Some examples of intrusive igneous rocks include:
GRANITE
GABBRO
Extrusive: These igneous rocks form when lava cools
quickly at Earth’s surface. They cool so quickly that only
very small crystals can grow. Extrusive igneous rocks are
often smooth(er) in texture because of the small crystal
formation.
Some examples of extrusive igneous rocks include:
OBSIDIAN
BASALT
Pumice