Bornite with Quartz, Pyrite

specimen number:
2262186

location:
Butte, Silver Bow Co., Montana, USA

description:

Fine old time classic for the species and locality. Crystallized bornite quite nice across the top of a pyrite matrix with crystallized quartz. Slight damage present, this mainly to the quartz crystals. The specimen comes with several antique labels as shown at the end of the video. Note that these labels give the locality as the Cahn Mine. I think it likely that this is meant to be the Mountain Con Mine.

The Butte mining district, located in Silver Bow County, Montana, is a legendary ore deposit known historically as "The Richest Hill on Earth," and it is world-famous for producing exceptional specimens of crystallized bornite. Geologically, the district is hosted within the late Cretaceous-age Boulder Batholith, specifically the Butte Quartz Monzonite, which was extensively fractured and mineralized by complex, deep-seated hydrothermal vein systems. Within these massive sulfide veins, bornite occurred abundantly as a primary copper ore, frequently forming sharp, dark metallic gray cubic and dodecahedral crystals that develop a vivid, iridescent blue and purple tarnish upon exposure to air. Placer gold mining began in the area in 1864, but the district transitioned to underground silver mining in the 1870s and then to large-scale copper extraction by the 1880s to meet the global demand for electricity. Giant underground operations dominated the district until 1955, when the transition to the massive Berkeley Pit open-pit operation took place, with mining activities continuing intermittently through various corporate owners into 2026 at the Continental Pit.

Lawrence Conklin was a world-renowned mineral dealer based in New York City, widely regarded as one of the most knowledgeable and sophisticated figures in the history of the mineral trade. Operating from his office on 5th Avenue and later from his home in Connecticut, Conklin specialized in "antique" minerals and specimens with significant historical provenance. He was a meticulous researcher and an elegant writer, often publishing articles that corrected historical errors in mineralogical literature. His career spanned over five decades, during which he handled some of the finest known specimens from classic European and American localities, setting a high standard for aesthetic quality and documentation in the field.

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