GRANITE...

Granite is nearly always massive (lacking internal structures), hard and tough, and therefore it has gained widespread use as a construction stone.

Granite containing potassium feldspar, plagioclase feldspar, quartz, and biotite and/or amphibole and its composition: Potassium feldspar, plagioclase feldspar, and quartz; differing amounts of muscovite, biotite, and hornblende-type amphiboles.