Thumbnails can be downloaded. The Story of Igneous Rock Igneous rock is formed when molten magma from deep within the earth cools and finally freezes into solid form. If the rock has cooled slowly below the surface, individual crystals will grow larger before intersecting, and coarse grained plutonic rocks such as granite are formed. This site contains a multiple-choice quiz on igneous rocks. Its is suited to high school level students.
Igneous rocks form from magma crystallizing below earth's surface or from volcanic activity.
Igneous rocks are classified on their texture and their composition. Some are called extrusive igneous rocks. This lava solidifies on the earth's surface. Sometimes this lava is thrown out by volcanoes as volcanic lava bombs. Granite Granite is one of the most common rocks on our planet.