Montana Bark is often referred to as Montana Bark Jasper, but it is acutally a fossiliferous form of dolomite. It is the fossilized remnant of an ancient streambed. It cuts and polishes easily and will cut fine spheres, slabs and cabochons. This material is old stock from our “archives”.
Montana Bark takes an excellent polish with diamond or tin oxide. MOHs hardness is 3.5 to 4.