This Specimen has been sold.
4.3" Dark Purple Cubic Fluorite Crystal Plate - China
This is a stunning association of dark purple, cubic fluorite crystals on/in quartz. Some of the fluorite crystals fluoresce under long wave UV, however the darker, more opaque crystals don't display much fluorescence, if any at all. Most of the crystals are in pristine condition, some of which have been cleared of the quartz aggregation that formed over them. One edge of this cluster has been cut flat, allowing for aesthetic presentation of the specimen without the need for a display stand.
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.
Silicon Dioxide, also know as SiO2 or Quartz, is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich, hot watery solutions called hydrothermal environments, at temperatures between 100°C and 450°C, and usually under very high pressure. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountains forming, and can be hundreds of millions of years old.