Barite

Unknown Owner

Colorless to light blue lustrous beautifully arranged crystals of barite with little attached matrix. In excellent condition. From the mid 1970s, this is classic material for this locality and species. Crystallized nicely all around.The Crystal Mine, located near Cave-in-Rock in Hardin County, Illinois, was a significant producer of fluorspar within the Illinois-Kentucky Fluorspar District. Geologically, the deposit consists of Mississippi Valley-Type (MVT) mineralization, where hydrothermal fluids replaced specific layers of Mississippian-aged limestone, such as the Fredonia Limestone, to form extensive bedded-replacement ore bodies. This process created large, open pockets where minerals could crystallize freely, resulting in some of the finest fluorite specimens in North America. Historically, the mine operated primarily during the mid-20th century, with significant activity occurring from the late 1930s through the 1950s under the ownership of companies like the Minerva Oil Company. The mine is legendary among collectors for its world-class fluorite crystals, which typically exhibit a beautiful zoning of purple and yellow colors, often accompanied by associated minerals like sphalerite, galena, and barite. Though industrial operations have long since ceased, the specimens recovered during its decades of production remain cornerstones of major museum and private collections worldwide.