Barite with Calcite

Unknown Owner

Gorgeous gem prismatic terminated crystals of barite, the prominent crystal 4.8 cm in height, set on matrix with golden yellow crystals of lustrous calcite. Brightly fluorescent. In super condition.The Elk Creek locality, situated in Meade County, South Dakota, is globally famous for producing world-class honey-yellow barite crystals hosted within large concretions. Geologically, these specimens are found in the Pierre Shale, a Late Cretaceous marine sedimentary formation that contains numerous septarian nodules and concretions. The barite formed as secondary mineralization within the internal shrinkage cracks of these nodules, resulting in elongated, prismatic crystals with exceptional transparency and a brilliant vitreous luster. These crystals are often associated with yellow or colorless calcite and can reach lengths of over 10 centimeters. Historically, this is not a traditional industrial mine but rather a series of specialized specimen-collecting sites on private ranch lands. Active collecting for the mineral market began in earnest during the mid-20th century and has continued intermittently to the present day, with the 1980s and 1990s being particularly productive decades. Because the concretions are buried in tough, unweathered shale, recovery requires significant mechanical excavation. Today, Elk Creek barite is considered the definitive representative for the species from the United States, prized by collectors for its iconic golden-amber color and sharp, undamaged terminations.