a piece of raw purple sandstone rock on white background. pink arkosic sandstone.

arkose arkosic background black carbon clastic coal common composed crystal decoration emerging feldspar fragments fuel geology grains granite granitic hand holding isolated macro mainly material mine mineral mining mixture most natural nature object ore organic piece pink potash quartz raw reef reefs rock rocks rocky sandsized sandstone sandstones sea sedimentary silicate specimen stone strange texture these two types unusual white