Commercial granites include all feldspathic crystalline rocks of mainly interlocking
texture and with individual mineral grains that are visible to the naked eye. This
category includes such rock types as anorthosite, gneiss, granite, granodiorite, monzonite,
syenite, and all other intermediate igneous and coarse-grained metamorphic rock types.
Primary colors of commercial granites are white, gray, pink, and red; green and brown
are secondary colors. Although black granites are also included in this category and
range in color from dark gray to black, they are not true granites mineralogically
but rather mafic rocks, such as diabases, diorites, gabbros, and similar rocks.