12.3" Smoky Quartz Crystal Cluster on Metal Stand - Brazil
This is a dark black, smoky quartz crystal cluster from Brazil. The crystals have not been polished and are in excellent condition. The only notable damage is to the termination of the horizontal crystal near the base. It has not been heated or treated to change the natural color. This specimen is accompanied by a custom metal display stand.
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.
Smoky quartz is a grey-brown to black variety of quartz. This common name is derived from from the appearance of smoke within the quartz crystal. Dependent on the location and the chemicals present during formation, smoky quartz can appear opaque black, however it’s typically translucent to some extent. It’s believed that the quartz gains this color from a combination of natural irradiation and aluminum impurities.