Fluorescent OpalFluorescent OpalMexicoA fascinating, oval-cut hyalite opal that reveals its fluorescent green glow in shortwave ultraviolet light. Hyalite opal is formed by hot spring geyser deposits and does not have color play like other opal, instead the light rolls off the internal bubble structure and flashes back at the onlooker. Weighing approximately 4.44 carats and measuring 13.86 x 10.85 x 6.84mm None