3.8" Quartz Crystal Cluster - Brazil
This is a beautiful cluster of quartz crystals from Brazil. There are inclusions within the quartz crystals, some of which appear to be chlorite (green).
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.