Fluorite is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals.
Fluorite is a widely occurring mineral that occurs globally with significant deposits in over 9,000 areas. It may occur as a vein deposit, especially with metallic minerals, where it often forms a part of the gangue (the surrounding “host-rock” in which valuable minerals occur) and may be associated with galena, sphalerite, barite, quartz, and calcite.
Fluorite is allochromatic, meaning that it can be tinted with elemental impurities. Fluorite comes in a wide range of colors and has consequently been dubbed “the most colorful mineral in the world”. Every color of the rainbow in various shades are represented by fluorite samples, along with white, black, and clear crystals. The most common colors are purple, blue, green, yellow, or colorless. Less common are pink, red, white, brown, and black. Color zoning or banding is commonly present.
Many samples of fluorite exhibit fluorescence under ultraviolet light, a property that takes its name from fluorite. Many minerals, as well as other substances, fluoresce. The color of visible light emitted when a sample of fluorite is fluorescing depends on where the original specimen was collected; different impurities having been included in the crystal lattice in different places.