Calcite with Fluorite

Unknown Owner

Lustrous colorless to slightly yellowish gemmy scalenohedral crystals of calcite measuring to 2.5 cm in length across the top of a crystallized fluorite matrix. Minimal cleaving present, this still in good condition and quite attractive.Mining in the southern Illinois fluorspar district developed in the 19th century in Hardin and Pope counties along the Ohio River. The region became one of the most important sources of fluorite in the United States during the early to mid 20th century. Mines worked vein and replacement deposits hosted in limestone and produced fluorite along with associated minerals such as calcite, galena, and sphalerite. The fluorspar was widely used in steel making and chemical industries, and the district was also known for colorful fluorite specimens.