3" Brilliant Blue-Green Chrysocolla on Quartz - Tentadora Mine, Peru

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.

Chrysocolla is a basic copper silicate that typically forms as a pseudomorph following other copper based minerals. The chemical formula is considered undetermined due to the varying substitutions of elements and water content in its chemical structure. However, there is a form of chrysocolla with an identifiable chemical formula of Cu2H2Si2O5(OH)4 that can be found in microcrystals.

Regularly, chrysocolla will form as botryoidal lumps and spheres, rarely forming visible crystals. It can also form in both solid and fibrous veins, over fibrous minerals, and in crusts. Known for its sharp and vibrant coloring, chrysocolla can display a wide variety of colors such as bluish-green, bright green, light blue, to even sometimes multicolored specimens depending on the atmosphere present during formation.