2.85" Orange Cave Calcite Formation - Peru
This is a beautiful formation of orange cave aragonite (aka cave calcite), collected from the Pachacayo Mine in Junín, Peru. When viewing the mineral under short and long wave UV, this specimen fluoresces a faint, white-yellow color. Following extended UV exposure, the aragonite displays phosphorescent properties that remain for a short time.
Aragonite is a carbonate mineral with the chemical composition of CaCO3. It is a pseudomorph after calcite and varies in colors depending on impurities. It displays a translucent to white color when pure, and when impure can vary between yellow, green, pink, blue and brown. Typically forming in low temperature hydrothermal veins, It is also known to form in hot springs, as precipitates from chemicals in sedimentary rock, and in some cases as crystals in fossilized sea creatures.