Granite stones form from magma, commonly known as lava. Common ingredients include feldspar and quartz (feldspar imparts its red color). Granite also contains mica and other minerals in smaller amounts, including apatite, zircon, magnetite, sphene and ilmenite, which gives it its characteristic shade and crystalline structure. They are stronger than many other natural stones and tolerate weathering as well. They are mainly used as building material.