5" Realistic, Polished Quartz Crystal Skull
This is a 5" long, polished quartz crystal skull from Madagascar. This quartz specimen has undergone intricate sculpting and polishing that left the crystal in the shape of a skull. The underside of the skull and the nostrils have been hollowed-out, making the specimen closer in resemblance to a real skull.
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.