Granite is a coarse- or medium-grained intrusive igneous rock that is rich in quartz and feldspar. It is the most common plutonic rock of the Earth’s crust, forming by the cooling of magma (silicate melt) at depth. Because of its use as a paving block and as a building stone, the quarrying of granite was, at one time, a major industrial activity. Except for tombstones, however, for which there is a continuing demand, the present production of granite is geared to the fluctuating market for curbing in highway construction and veneer used in the facing of large industrial and commercial buildings.

Source: Britannica