A classic, old-time copper specimen from the historic Phoenix Mine of Michigan's Copper Country. This superb, two sided miniature is a sculptural arborescent cluster of very sharp copper crystals with a nice patina. Most of the crystals on this specimen are tetrahexahedrons, but his fine piece features at least one rare, 3 mm, dodecahedral crystal on the middle, left side of the cluster. Ex. Karl Warning Collection.