2.8" Quartz Crystals on Atacamite - Peru

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.

Atacamite is a secondary copper mineral that's formed from the oxidation of copper minerals. It has the chemical formula Cu₂Cl(OH)₃ and forms as slender prismatic crystals, fibrous crystals and as granular to compact aggregations. Atacamite was first described by D. de Fallizen after specimens found in the Atacama Desert of Chile in 1801.