Geography,

Igneous Rocks Facts

Igneous rocks are those that form when magma cools and hardens. This process can occur on the Earth’s surface or underground.

Ninety-five percent of the Earth’s crust is made of igneous rock.

There are over 700 different kinds of igneous rocks that have been identified

When magma rises to the surface of the Earth and hardens, it forms extrusive igneous rock.

Examples of extrusive igneous rock include pumice and basalt.

Pumice is used in many products such as toothpaste, cement, and cosmetic products

Basalt is used in constructing buildings and statues.

When magma cools and hardens below the Earth’s surface, an intrusive igneous rock forms.

Examples of intrusive igneous rock include granite and gabbro.

Granite is used as for making gravestones, statues, and countertops because it is very durable.

Gabbro contains profitable amounts of gold, chromium, and silver.

Plutons are bodies of intrusive rock which are usually composed of granite

A batholith (from Greek bathos, depth + lithos, rock) is a large emplacement of igneous intrusive (also called plutonic) rock that forms from cooled magma deep in the Earth’s crust.