2.3" Purple/Gray Fluorite Cluster - Marblehead Quarry Ohio
This cluster of lustrous purple/gray fluorite is from the Marblehead Quarry in Ohio. Most of the crystals shown are around 2-3mm across, some slightly larger. There is also calcite present in this specimen.
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.