UV-Reactive Crystals
Some minerals glow under ultraviolet light — a striking identification clue. Fluorite literally gave fluorescence its name. This is a starter list; UV reaction varies by specimen and locality.
Commonly fluorescent or UV-reactive minerals include fluorite, calcite, aragonite, selenite, scapolite and many secondary uranium and manganese minerals. Reaction depends on trace activators, so always test your own specimen.