How do extusive igneous rocks form?

Answer 1

Extrusive igneous rocks form when magma erupts as lava above Earth's surface. The resulting lava cools rapidly on Earth's surface. As a result, minerals do not have time to form. An example of an extrusive igneous rock is pumice.

Answer 2

Extrusive igneous rocks form when magma from deep within the Earth rises to the surface and cools quickly, either on the surface as lava or in shallow underground chambers called volcanic pipes. This rapid cooling prevents the formation of large crystals, resulting in fine-grained rocks like basalt or rhyolite.