This Specimen has been sold.
4.8" White Aragonite and Calcite Formation - Fluorescent
This is a beautiful formation of fluorescent calcite with aragonite, from Morocco. When viewing the mineral under natural and artificial light, aside from the interesting white botryoidal formations, the mineral may seem slightly uninspiring. But when placed under shortwave UV light, this mineral fluoresces a white-green color, thats phosphorescence lingers for some time following removal of the UV light.
Stalactites form when water that seeps through rock, reaches an opening such as a cave or tunnel. Once this mineral rich water (calcite in this case) precipitates out of the rock wall/ceiling, it leaves behind a crystal as the precipitate builds with each drop of water. Stalagmites are likely to form from this process, for the drops from the ceiling will still contain high mineral content, typically depositing a precipitate that will continue to build as long as water continues to flow in this location.
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.