IGNEOUS ROCKS

Igneous rocks are formed from molten magma or lava. The word, igneous means "fire".

All igneous rock starts deep in the earth as hot, molten magma. If the magma cools and hardens inside the earth it is called "intrusive" rock. These rocks cool slowly and have large crystals.

When the magma comes out of the earth's crust through a volcano, it is called "extrusive". It cools off quickly, and the crystals that form are very small.

Molten, or hot, liquid rock is called MAGMA when it is still inside the earth, but once it comes out through a volcano it is called LAVA.

Click on the names of igneous rocks below to see some neat pictures.