3.8" Quartz Crystal Cluster - Arkansas

Quartz from the Ouachita Mountains of Arkansas and Oklahoma has been known ever since indigenous Americans had first occupied the area: they worked the quartz into projectiles for hunting and fishing. It has been commercially mined since the 1890s.

Quartz is the name given to silicon dioxide (SiO2) and is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich environments--usually igneous rocks or hydrothermal environments like geothermal waters--at temperatures between 100°C and 450°C, and usually under very high pressure. In either case, crystals will precipitate as temperatures cool, just as ice gradually forms when water freezes. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountain formation: these veins can be hundreds of millions of years old.