All rubies fluoresce, whether they are natural or created in a lab. Natural and synthetic ruby gemstones have the same chemical composition and physical properties. However, there are slight differences in fluorescence patterns between natural and synthetic stones and even between natural rubies from different sources.
Thereof, what gems glow under black light?
Minerals with fluorescence stop glowing when the light source is turned off. Minerals with phosphorescence can glow for a brief time after the light source is turned off. Minerals that are sometimes phosphorescent include calcite, celestite, colemanite, fluorite, sphalerite, and willemite.
Do Rubies shine?
How do you know if a ruby is real?
Real rubies glow with a deep, vivid, almost "stoplight" red. Fake gems are often dull: they are "light, but not bright." If the gem is more of a dark red, then it may be garnet instead of a ruby. If it is a real ruby, however, know that darker stones are usually worth more than lighter stones.