2" Fluorite and Quartz, Fujian Province, 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.
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.