1.8" Creedite Crystal Cluster with Fluorite - Dachang Mine, China

Creedite is a complex aluminum salt with the chemical formula of Ca3SO4Al2F8(OH)2 · 2H2O. It typically forms from metamorphic rock as a fluorite oxidation in fluorite ore deposits. Generally crystals form in radial aggregations, but under rare circumstances will form as single prismatic crystals up to 1 millimeter long. Creedite has been found in a variety of different colors, but most often displays orange, purple, or clear colorless crystals.

Fluorite is a halide mineral comprised of calcium and fluorine, CaF2. The word fluorite is from the Latin fluo-, which means "to flow". In 1852 fluorite gave its name to the phenomenon known as fluorescence, or the property of fluorite to glow a different color depending upon the bandwidth of the ultraviolet light it is exposed to. Fluorite occurs commonly in cubic, octahedral, and dodecahedral crystals in many different colors. These colors range from colorless and completely transparent to yellow, green, blue, purple, pink, or black. Purples and greens tend to be the most common colors seen, and colorless, pink, and black are the rarest.