Copper with Calumetite

specimen number:
2062059

location:
Calumet and Hecla Mine, Houghton Co., Michigan, USA

description:
Branching crystallized native copper in a cluster with minor attached breccia matrix. There is bluish green crystalline calumetite throughout.

The Calumet and Hecla Mine in Houghton County, Michigan, was one of the most productive copper mines in the history of the United States. Mining began in the 1860s when rich native copper deposits were discovered in the Calumet Conglomerate within the Portage Lake Lava Series. Operated by the Calumet and Hecla Mining Company, the mine developed extensive underground workings and became a major center of copper production in the Keweenaw Peninsula. The mine produced large masses of native copper along with associated minerals such as calcite, quartz, and datolite found in cavities within the host rock. Operations continued into the early 20th century before the mine eventually closed.

Questions about this specimen?
Send an email or call us: 314-341-1811.