This Specimen has been sold.
4.3" Polished Quartz Sphere - Madagascar
This is a 4.3" wide, polished quartz sphere from Madagascar. This sphere has been polished into a perfect round sphere from a larger chunk of quartz. Iron oxidation can be seen throughout the sphere, indicated by the orange tint to some of the quartz. The specimen weighs 4.1 lbs and 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.