FLUORITE (miniature, micromount crystals)

Fluorite, also known as fluorspar, is the mineral form of calcium fluoride (CaF2) and is classified among the halide minerals. It typically crystallizes in an isometric cubic structure, although octahedral and more intricate forms can also be found. On the Mohs scale of mineral hardness, fluorite is assigned a value of 4, indicating its relative hardness. While pure fluorite is colorless and transparent under both visible and ultraviolet light, impurities often impart vibrant colors, making it a popular choice for ornamental and lapidary applications. In industrial contexts, fluorite serves as a flux in smelting processes and is utilized in the manufacture of specific glasses and enamels. The highest purity grades of fluorite are essential for producing fluoride, which is a key component in the production of hydrofluoric acid, a precursor for many fluorine-containing fine chemicals. Additionally, optically clear fluorite exhibits unique properties, such as anomalous partial dispersion, which allows its refractive index to vary with light wavelength, making it advantageous for crafting apochromatic lenses and valuable in photographic optics. Fluorite's optical characteristics extend to the far-ultraviolet and mid-infrared ranges, where traditional glasses are ineffective, and it is noted for its low dispersion and high refractive index relative to its density.