Chalcocite

specimen number:
8311408

location:
Flambeau Mine, Rusk Co., Wisconsin, USA

description:
Very attractive purplish iridescent crystallized cluster of chalcocite without matrix. Naturally crystallized all around and in great condition. Collected in the 1990s.

The Flambeau Mine, located near Ladysmith in Rusk County, Wisconsin, was a high-grade volcanic-associated massive sulfide (VMS) deposit situated within the Paleoproterozoic Penokean Volcanic Belt. Geologically, the ore body consisted of a steeply dipping lens of primary copper and iron sulfides that had undergone significant supergene enrichment, creating an exceptionally rich secondary enrichment zone beneath the glacial till. This locality is most famous for its world-class chalcocite specimens, which occurred as sharp, lustrous, metallic-gray crystals, often exhibiting a beautiful iridescent "peacock" tarnish or associated with native copper and bornite. Historically, the deposit was discovered in 1968 by Kennecott Explorations, but due to extensive environmental permitting and legal deliberations, mining did not commence until 1991. The Flambeau Mining Company operated the site as a relatively small open-pit mine from 1993 until the ore was completely exhausted in 1997. Following the cessation of mining, the site underwent a rigorous reclamation process that saw the pit backfilled and the land restored to a natural meadow and woodland, leaving the mine as a significant, though short-lived, chapter in American mineralogical history.

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