UV-SENSITIVE MINERALS (Longwave & Shortwave)
Fluorescence in minerals occurs when a specimen is illuminated with specific wavelengths of light. Ultraviolet (UV) light, x-rays, and cathode rays are the typical types of light that trigger fluorescence. These types of light have the ability to excite susceptible electrons within the atomic structure of the mineral. These excited electrons temporarily jump up to a higher orbital within the mineral's atomic structure. When those electrons fall back down to their original orbital, a small amount of energy is released in the form of light. This release of light is known as fluorescence.
Most minerals do not have a noticeable fluorescence. Only about 15% of minerals have a fluorescence that is visible to people, and some specimens of those minerals will not fluoresce. One of the first people to observe fluorescence in minerals was George Gabriel Stokes in 1852. He noted the ability of fluorite to produce a blue glow when illuminated with invisible light "beyond the violet end of the spectrum."
He called this phenomenon "fluorescence" after the mineral fluorite.