Igneous rocks result from the cooling of hot, molten rock material or
_magma_. Magma that reaches the surface through volcanoes is called
_lava_. Magma comes from deep within the earth and is made up of a
mixture of molten mineral materials. Igneous rocks have been forming
throughout the geologic past and are still forming today. We can
understand how they form when we look at pictures of hot, molten lava
flowing from volcanoes, such as Mauna Loa in Hawaii. As lava cools, it
hardens into rock.