This unusual copper specimen is colored a lustrous, chocolate brown by a combination of old patina mixed with a coating of the mineral tenorite. Additionally, it is composed mostly of copper cubes, to 6 mm across. Cubic copper crystals are a real rarity from this or any mine, and are highly desired by collectors. The back side has a vuggy crust of epidote from which emanate a druse of glassy, pistacchio-colored epidote crystals. A combination of a rare form, unusual patina and interesting accessory mineral.