EXTRUSIVE ROCKS
 WHAT THEY ARE
They are rocks that have been cooled very quickly and have very small crystals if any at all. Some cooled that they even have holes in them.

FORMATION
Magma is pressured and blown out of a volcano or fissure
The magma gets pushed up very quickly
Comes to surface and cools down rapidly
Accumulates very little crystals

COMMON ROCKS
Basalt
Pumice
Rhyolite
Scoria

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