This is a 3.9" wide, polished quartz sphere from Madagascar. This sphere has been polished into a perfect round sphere from a larger chunk of quartz. The chatoyance portions of the sphere are stunning, and the specimen weighs 3.1 lbs. Comes with pictured display stand.
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.