Igneous Rocks form when either magma or lava cools.

Igneous Rocks

Extrusive Igneous Rocks

Intrusive Igneous Rocks

Intrusive Igneous rocks form when magma cools and solidifies beneath the earths surface forming larger crystals because they have more time to cool. EXAMPLE: Granite

Extrusive Igneous rocks form when magma flows onto the surface, now lava, cools and solidifies forming fine grain crystals because they have less time to cool. EXAMPLE Obsidian