3.1" Multicolored Cubic Fluorite Crystal Cluster - Inner Mongolia

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.

Arsenopyrite is an iron arsenic sulfide with the chemical formula FeAsS. It is the most common arsenic-bearing mineral and is its principal ore, and can be found in igneous, metamorphic and sedimentary rock. Crystals can be found as prismatic, twinned, columnar, elongated and massive formations within veins and are found in locations all around the world. Depending on minerals present during formation, the iron in arsenopyrite can be replaced by cobalt, forming cobaltite.

Arsenopyrite contains a significant amount of poisonous arsenic, making it somewhat toxic. Washing hands following handling is recommended.