Chalcopyrite with Galena

Unknown Owner

Beautiful iridescent crystals of chalcopyrite to almost 1.0 cm in size across the top of a galena matrix. This is crystallized completely all around and in very good condition. This would have been collected around 2011.The Sweetwater Mine, located near Ellington in Reynolds County, Missouri, is a major lead-zinc-copper operation within the world-class Viburnum Trend. Geologically, the deposit is a classic Mississippi Valley-Type (MVT) occurrence where mineralizing fluids replaced the Cambrian-aged Bonneterre Formation limestone and dolomite, particularly along the margins of Precambrian basement highs. The mine is famous among mineralogists for producing spectacular specimens of lustrous, golden-yellow chalcopyrite crystals often associated with rhombohedral calcite, dark sphalerite, and galena. Historically, mining and quarrying activities at the site began in the late 1960s, with the mine officially opening in 1970 under the operation of the Ozark Lead Company, a subsidiary of Kennecott Copper. The facility was later acquired by ASARCO and eventually by the Doe Run Company, which continues to operate the mine as a significant global source of lead and zinc. Throughout its history, the Sweetwater Mine has been a consistent producer of both industrial metals and museum-quality crystal groups, maintaining its status as a cornerstone of Missouri's New Lead Belt. Today, the mine remains an active and technologically advanced pillar of the American mining industry, with its geological legacy and specimen production continuing through 2026.