Granite is a coarse grained crystalline igneous rock composed primarily of quartz and feldspar.
Granite characteristically forms irregular masses and makes up a large part of every continent. The size of these masses can be extremely varied. Sometimes they form small masses that measure less than eight kilometres on one side and sometimes they form huge masses covering thousands of kilometres in area. They may also occur in dikes or sills, that is tabular bodies injected in fissures and inserted between other rocks. Scientists have concluded that most granite is formed by slow cooling and crystallisation of magma, a molten material.