Arkansas sharpening stones are from Quachita Mountains in USA. The Arkansas sharpening stones are oilstones and are very suitable for sharpening carving and turning tools, because they are very dense and wear-resistent. They are made of Novaculite, it is a form of microcrystalline or cryptocrystalline quartz. The color varies from white to grey-black and the specific gravity shows an increase from 2.2 to 2.5. The very hard dense rock is used as a whetstone. It has been mined since prehistoric times both as material for use as arrow and spear points and as sharpening stones. Grit approx. 6000-8000.