2.2" Chalcopyrite, Sphalerite, Galena and Quartz Association - Peru

Galena is a lead-based mineral and the primary ore of lead, and has been used for its lead content for thousands of years. Galena typically displays a gray metallic luster and forms cubes or octahedral crystals. The chemical composition of galena is PbS.

While galena will not pose a health hazard by sitting on the shelf or even from casual handling, we suggest washing hands following handling due to the mineral's lead content.

About Quartz

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.

Sphalerite is a part of the sulfide group and typically exhibits a grey/black appearance due to high concentrations of impurities. In its purest state, sphalerite's chemical composition is ZnS, and can display a gemmy transparent light tan/yellow color. This is one of the few minerals that can form crystals ranging anywhere between gemmy and transparent to opaque and metallic-like. Opaque or cloudy sphalerite tends to be most abundant since iron easily replaces zinc in the process of formation.

Chalcopyrite is a brass-yellow colored mineral and an important copper ore. When weathered, chalcopyrite loses its metallic luster, turning a gray-green color. When exposed to acids, the tarnish can develop a red, blue, or purple iridescence: this acid-treated material is often sold under the name peacock ore.