THIS is a really nice specimen!! Two in one really. One side is a concave plate of well formed rhombohedral smithsonite crystals with perhaps a slight yellow tint. The other side of the piece which is mostly smithsonite shows a convex mound of smithsonite crystals harly noticeable under a covering of sharp, colourless willemite crystals and tiny brown pyritohedra. I am assuming the brown pyritohedra are pseudos of goethite after pyrite. The willemite crystals are fluorescent. I have a close-up of the willemite crystals if you would like to see it. Just ask! Great looking specimen from top and bottom!