This Specimen has been sold.
4.2" Smoky Quartz Crystal with Spessartine Garnets - China
This is a 4.2" long natural smoky quartz crystal that is partially encrusted in orange spessartine garnets from China. There is some chipping to the termination and many of the garnets appear to have broken free from the smoky quartz crystal.
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.
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.
Spessartine, often mistakenly referred to as spessartite, is a nesosilicate, manganese aluminium garnet species with the chemical formyla Mn2+3Al2(SiO4)3. The name is a derivative of Spessart in Bavaria, Germany, the type locality of the mineral.