natural mineral stone flint, sedimentary cryptocrystalline form of the mineral quartz

archeology brown chalcedony chalk chert closeup cobble crypto cryptocrystalline crystal crystalline deposits firestone flint form formation gem gemology gemstone geologic geological geology limestone macro material mine mineral mineralogy minerals mountain natural nature nodule ore paleontology pebble pebbles pebbly piece quartz raw rock rough sedimentary shiny stone stones structure surface texture weapon