Copper

specimen number:
8311556

location:
Copper Falls Mine, Keweenaw Co., Michigan, USA

description:

Fine an aesthetic grouping of native copper crystals without matrix. In terrific condition all around.

The Copper Falls mine, situated near Eagle Harbor in Keweenaw County, Michigan, United States, was a highly prominent mid-nineteenth-century underground native copper operation celebrated for its technological innovations and rich mineral specimens. Geologically, this deposit is hosted within the Mesoproterozoic-age Portage Lake Volcanics of the Midcontinent Rift System, where mineralizing hydrothermal fluids filled structurally controlled fissures, faults, and porous basaltic flow tops, specifically concentrating massive native copper, native silver, and exceptional specimens of copper, silver, datolite, analcime, and prehnite within the cross-cutting Owl Creek fissure and the Ashbed amygdaloid lode. Historically, the Copper Falls Mining Company was formally organized in 1845, making it one of the earliest structured ventures in the district, and miners initially struggled with erratic fissure veins before driving the famous Owl Creek adit in the 1850s and constructing early stamp mills to process the amygdaloidal rock. The mine operated with mixed financial success through several corporate reorganizations, achieving its most steady production phase during the late 1870s and 1880s before declining ore grades and high deep-mining costs finally forced a permanent cessation of all commercial underground operations in August 1893.

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