Cave-in-Rock Fluorite

Cave-in-Rock Fluorite Cave-in-Rock, Illinois is known for its fluorite deposits, a halide mineral composed of calcium and fluorine (CaF2). Fluorite from this area often exhibits vibrant colors like purple and green, though it can also be colorless, yellow, blue, pink, or black. The crystals commonly form in cubic shapes and can display zoned growth patterns with various inclusions, such as sphalerite and chalcopyrite. Properties of Cave-in-Rock Fluorite: Composition: Calcium fluoride (CaF2). Crystallography: Typically found in cubic crystals, but can also form octahedral and dodecahedral shapes. Color: Ranges from colorless and transparent to purple, green, yellow, blue, pink, and black. Purple and green are the most common. Luster: Often has a vitreous or waxy luster. Inclusions: May contain inclusions of other minerals like sphalerite and chalcopyrite. Fluorescence: Fluorite can fluoresce under ultraviolet light, exhibiting different colors than its visible color. Location: Found in the Cave-in-Rock subdistrict of Hardin County, Illinois. Uses: Fluorite is used as a flux in smelting, in the production of certain glasses and enamels, and as a source of fluoride for hydrofluoric acid production.