What is Granite? The word granite comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a crystalline rock. Granite is a common and widely-occurring group of intrusive felsic igneous rocks that form at great depths and pressures under continents. The average density is 2.75 g/cm3 with a range of 1.74 to 2.80 g/cm3.

Occurrence of granite Granite has been intruded into the crust of the Earth during all geologic periods, except perhaps the most recent; much of it is of Precambrian age. Granite is widely distributed throughout the continental crust of the Earth and is the most abundant basement rock that underlies the relatively thin sedimentary rock veneer of the continents.