If magma erupts on the surface as lava, it will form extrusive rock, e.g. basalt. These rocks are formed when magma solidifies. As the magma cools, mineral crystals will begin to grow. These ...

Igneous rocks form from the solidification of molten rock ... or at the surface following a volcanic eruption, producing extrusive or volcanic igneous rocks like basalt. As magma cools, the ...