Only around 15 percent of all minerals have the ability to fluoresce in ultraviolet light. In order for a mineral to fluoresce, it must contain an "activator" impurity such as a metal cation or a rare earth element.
Fluorite was the first observed fluorescent mineral and it glows blue. Calcite has been observed to glow many different colors including red, blue, white, pink, green and orange. Scapolite has been observed to have a yellow glow under ultraviolet light.
