Species: Copper, Calcite
Locality: Lake Superior Copper District, Houghton County, Michigan USA
Dimensions: 5 x 4 x 3.4 cm.
Copper-included calcite crystals from the Michigan Copper Country are some of the most sought-after calcites on earth for good reason- they are incredibly aesthetic, often water-clear and lustrous, and can be highly-complex in terms of form. Good undamaged examples are very scarce on the market these days, as most are either squirreled away in museum or private collections, or are heavily damaged from when they were sometimes carelessly collected in the 19th and early 20th centuries. This very fine example features a group of glassy, transparent doubly-terminated crystals which fully surround a small mound of matrix. The specimen shows nicely from both sides and the calcite crystals have a bright luster and “lively” copper inclusions. From the noted collection of Quincy mine captain S.B. Whiting, and later in the collection of the Philadelphia Academy of Sciences. Annette Slade photos.