What Is Ultraviolet?

Abstract

Scheelite fluoresces bright blue only under short wave ultraviolet light, and ruby fluoresces bright red primarily under long wave ultraviolet. Some minerals will fluoresce one color under short wave and a different color under long wave. Calcite from Terlingua, Texas, is a spectacular example of this, fluorescing bright blue under short wave, bright pink under long wave. Other fluorescent minerals are more or less impartial. Some willemites and some uranium minerals will fluoresce green; many fluorites will fluoresce blue; many calcites will fluoresce red under either short or long wave.