answersLogoWhite

0

Rocks formed under the surface of the Earth over a long period of time from cooling magma are called intrusive igneous rocks. At or near the surface, cooling lava creates extrusive igneous rock. Intrusive igneous rocks, like granite, will have visible, easily identifiable crystals which are due to the long amount of time spent in the crystal formation temperature range. Extrusive igneous rocks, like basalt, will not have visible crystals (seeing them requires magnification) due to the short amount of time spent in the crystal formation temperature range of the lava.

User Avatar

Wiki User

15y ago

What else can I help you with?