Copper

Help improve this record

No owner is registered for this specimen yet. If it's yours or you know more about it, you can add the owner, provenance, publications and other details.

Well crystallized twinned native copper in a cluster without matrix. In great condition. The White Pine mine, located in Ontonagon County, Michigan, was a major underground copper mine operated primarily by the White Pine Copper Company, a subsidiary of Copper Range. Geologically, the deposit is unique as a sediment-hosted stratiform copper deposit, where fine-grained chalcocite and native copper mineralization occur within the Proterozoic Nonesuch Shale, specifically at the contact with the underlying Copper Harbor Conglomerate. While small-scale mining at the site began as early as 1880, modern large-scale underground development commenced in 1952, with commercial production beginning in 1954 using room-and-pillar mining methods. The operation expanded to include a massive milling, smelting, and refining complex on-site, producing billions of pounds of copper until environmental regulations and declining copper prices led to the permanent cessation of mining operations in 1995.