2.7" Green Cuboctahedral Fluorite on Sparkling Quartz - China
This is a beautiful, 2.7" wide cluster of green cuboctahedral fluorite crystals that formed over a bed of druzy quartz crystals. This specimen was collected from Yongchun County, China.
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 known 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.