

Red Trinitite, a Piece of Atomic History
Red trinitite is technically not a true mineral, because it was not formed through a geologic process. Rather, this brick-red colored...


Longwave (LW) UV lights, blacklight tubes vs. LEDs.
365nm UV light is often called "blacklight". Before the advent of LW LEDs, blacklight fluorescent tubes, (the kinds used in hippie days...


Green hauyne and photochromic sodalite, Koksha valley, Afghanistan
Specimens like this are mostly sold as green and purple sodalite, but most are massive pieces. This piece contains part of a crystal that...


Aragonite and calcite, Forrières, Liège, Belgium
Yellow fluorescent aragonite due to organic impurities and possible lattice defects. Red fluorescent calcite showing Mn2+ and Ce3+-OH...