set of various gray unpolished rocks with names

amphibolite andesite antimonite argillite background bismuthinite black bornite cacholong chromite coal collage collection cuprite cutout description diorite dunite ferruginous gabbro galena galenite gemstone geological graphite hematite iron isolated jaspilite jaspillite magnetite marble melilitolite migmatite mineral mineralogical name natural olivinite ore quartzite raw rock rough set sphalerite stibnite stone unpolished various white