Cuivre natif sur calcite

Native Copper in Calcite
Keweenaw Copper Mining District, Upper Peninsula, Michigan, USA
Nearly half of the copper produced in the United States was mined in the Upper Peninsula during the 1870s and 1880s. The most aesthetic examples were collected and squirreled away in museums and private collections prior to World War I and the balance was sent to the smelter to create wire, pennies, piping, etc., particularly once the war effort began. The present specimen is a large cross-section slab displaying a wide vein of copper in calcite, with mirror-bright surface to the polished face with a thin protective coating, while the verso is natural and uncoated. All mining operations in Michigan are now closed. Weighing approximately 1.981 kilograms with the base and measuring 32 x 12 x 1 cm (39 x 12 x 10 cm with stand) (2)
Footnotes:
Offered with a custom-fitted black metal stand.
Lot to be sold without reserve.