Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or ...

Igneous rocks contain randomly arranged interlocking crystals. The size of the crystals depends on how quickly the molten magma solidifies and can form extrusive igneous rocks or intrusive igneous ...

Igneous rocks close igneous rockIgneous rocks ... If magma erupts on the surface as lava, it will form extrusive rock, e.g. basalt. These rocks are formed when magma solidifies.