Within this layer are places where the rock has melted. This melted or molten rock is called magma. When magma is forced to the surface of the earth, it is called lava. The world's first rocks were igneous. New igneous rocks are formed every day as magma or lava cools.
All rocks originally come from igneous rock.
When magma cools deep within the earth, it does so very slowly because it is not exposed to cool temperatures. Slow cooloing allows large crystals to develop in the rock. Rocks that form benearth the earth's surface, with either small or large crystals have a coarse texture and are known as intrusive igneous rock. Granite is a common intrusive igneous rock. Lava cools very quickly on the earth's surface because it is suddenly exposed to cool temperatures.