This classic, cabinet-sized copper "skull" is one of the most unusual forms in the Mineral Kingdom and is from the Copper Country of Michigan. This fine piece dates to around 1900. Copper invaded a conglomerate bed and surrounded a large, rounded cobble. The cobble dissolves away, leaving the casted "skull" of the cobble. This very fine example has a bright, copper patina and looks like a shallow bowl or chalice. Ex. Richard Hauck Collection.