This Specimen has been sold.
2.9" Quartz Stalactite Slice - Uruguay
This is a polished slice, of "stalactite" from within a quartz geode. These polished slices are gorgeous, displaying some wonderful banding. They come from the famous amethyst mines near Artigas, Uruguay.
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.
2.9" wide, about 1/4" thick