set of various unpolished gray rocks with names

acmite aegirine anthracite antimonite arsenopyrite background barite baryte basalt black carbonatite coal collage collection cut cutout description diorite galena galenite glance glaucophane granite gray haematite hematite iron isolated lead lodestone magnesite magnetite marble mineral molybdenite name natural ore out raw rock rough sample set shungite specimen stibnite stone unpolished various white