Cubic copper crystals are extremely rare in nature. This piece is made up of stacked cubes, sharp and obvious, to 7 mm in size individually. They form stacks and chains, though, and make for a robust cluster in combination. The piece as a whole has good aesthetics and a rich, natural patina untouched by acids and cleaning agents. It was illustrated in the copper country article in Rocks & Minerals, in 2007. The small, sadly short-lived Ojibway Mine is famous for such cubic coppers, though even here they were uncommon - and date to the early 1900s (the mine ran from 1907 - 1913 and produced 50,000 pounds of ore, only). Such pieces are true classics! BETTER In PERSON