If there are lots of light-colored minerals and the rock is coarse grained, it is granite.
Explanation:
Of the three principal rock types (igneous, sedimentary, and metamorphic), igneous rocks can be thought of as "primary" rocks because they crystallize from a liquid. Sedimentary and metamorphic rocks, which we will study later, may be thought of as derivative rocks.
Igneous rocks are rocks formed from the crystallization of a liquid (molten rock). Igneous rocks may be divided into two categories. Intrusive or plutonic rocks crystallize from magma beneath the earth's surface. Extrusive or volcanic rocks crystallize from lava at the earth's surface.