“[F]luorescence is triggered by ultraviolet light. . . . Burmese rubies fluoresce strongly to long wave . . . ultraviolet radiation and less strongly to shortwave radiation. . . .
    Rubies’ fluorescence is apparent in both artificial light and in some cases even in daylight, making the gem appear truly radiant. The fact that many Burmese rubies actually fluoresce to visible light is rather unusual. . . . The ancient Burmese considered this feature supernatural—and in some cases a product of witchcraft. . . .
    At one time it was believed that by looking into the strange, fiery fluorescence of Burmese rubies, one could see dragons and other mystical beasts.”

—Diane Morgan, Fire and Blood; Rubies in Myth, Magic, and History, 2008.