Q. Is black galaxy marble or granite?

This Black Galaxy Granite is primarily black with a few tiny white or gold sparkles. Black galaxy granite comes in slabs and tiles and has a variety of finishes including polished and honed. The Ongole region of South India is the source of black galaxy granite a stone material that belongs to the gabbro family. Also on “Moh's scale of hardness” granite is classified at 4.5 which is thought to be a moderately hard substance.