Marshall and Charlotte bought this as much for it being a relative bargain, I think, as for the unusual association with dolomite, which liberally coats the backside. They liked weird associations. However, since the knob isn't complete all around, you get a relative deal on a good disaply-sized cu-smithsonite since it still looks great from the front! Pristine and sparkly specimen. 6 x 5 x 5 cm