1.6" Atacamite, Calcite & Druzy Quartz Association - Peru

This beautiful specimen contains an association of druzy quartz crystals and vivid green atacamite, all on a large calcite crystal. It was collected from the Lily Mine in Pisco Umay, Peru and is 1.6" wide.

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.

Calcite, CaCO3, is a carbonate mineral and the most stable polymorph of calcium carbonate. The other polymorphs are the minerals aragonite and vaterite. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals. However, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, and prisms. Calcite exhibits several twinning types adding to the variety of observed forms. It may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form.

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.
Atacamite, Calcite & Quartz
Lily Mine, Pisco Umay, Ica Department, Peru
1.6" wide