Granite is an igneous rock composed mostly of two minerals: quartz and feldspar. It is an intrusive rock, meaning that it crystallized from magma that cooled far below the earth's surface. Its name is derived from the Latin word granum, which means grain, a reference to the easily-seen minerals in the rock. Two places where you might be most likely to encounter granite are kitchens and cemeteries. But the material's importance goes far beyond its uses, because it forms the foundation of our continents.