Calcite

Unknown Owner

Fine old classic specimen from Southwest Wisconsin with translucent lustrous colorless crystals of calcite to 8.0 cm in size on a sphalerite matrix. Slight micro-chipping present as seen, still in good condition. Said to have been collected in the 1940s.Mining at Shullsburg, Wisconsin, was a cornerstone of the Upper Mississippi Valley Zinc-Lead District, characterized by rich "flat-and-pitch" ore bodies. Geologically, these deposits formed via hydrothermal fluids that deposited minerals within the fractured Galena Dolomite and Platteville Formations during the Paleozoic Era. The primary ores consisted of galena (lead) and sphalerite (zinc), often found alongside beautiful accessory minerals like marcasite, pyrite, and calcite. Historically, Shullsburg became a focal point of the regional mining boom in the 1820s and 1830s, initially driven by shallow lead "diggings" by early pioneers. As technology advanced, the focus shifted to deeper zinc mining, with major operations like the Eagle-Picher Mine dominating the landscape through much of the 20th century. Large-scale commercial mining in the Shullsburg area continued until the closure of the last major mines in 1979, ending over 150 years of industrial production. Today, the area is recognized for its historic mining architecture and as a classic locality for world-class mineral specimens.