Copper

specimen number:
2242024

location:
Phoenix Mine, Keweenaw Co., Michigan, USA

description:
An attractive grouping of very thick well-formed crystals of native copper with minor attached matrix. This is in good condition.

The Phoenix Mine, located in Keweenaw County on Michigan's Keweenaw Peninsula, was one of the earliest industrial attempts to extract copper from the region's unique fissure veins. Geologically, the mine was situated on the Phoenix Vein and the Robbins Vein, which cut through the basaltic lava flows of the Portage Lake Volcanics, hosting significant deposits of native copper and occasionally native silver. Unlike the later, more successful amygdaloid or conglomerate mines, the Phoenix focused on vertical fissures where copper occurred in massive, pure forms rather than small grains. Historically, the property was first explored in 1844 by the Lake Superior Copper Company, making it one of the oldest mines in the district, and it was later reorganized as the Phoenix Copper Company in 1849. Operations were sporadic and plagued by financial difficulties, with major periods of production occurring between 1850 and 1886, followed by a brief, unsuccessful revival in the early 1900s.

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