Intrusive and Extrusive Igneous Rocks

Intrusive and Extrusive Igneous Rocks

Igneous rocks form when melted rock, such as magma or lava, cools and solidifies. These rocks are classified into two main types based on where the magma cools and solidifies: intrusive igneous rocks, which form underground, and extrusive igneous rocks, whic...

Igneous rocks form when magma cools and hardens. The rate and location of cooling affect the rock’s texture and color. These differences lead to two main types of igneous rocks.

Intrusive igneous rocks cool underground. Deep inside Earth’s crust, magma is surrounded by warm rock, so it cools very slowly.

This slow cooling gives crys...