beryl, synthetic beryl, emerald, gems

Dr. Frederick H. Pough, noted mineralogist and gemologist, supplied Gem News with the following information concerning the Russian hydrothermal synthetic emer-alds that have recently appeared on the colored-stone market. The emeralds show a refractive index of 1.574–1.580 with a birefringence of 0.006. They do not fluoresce to either long-wave or short-wave ultraviolet radiation, and their color-filter reaction is negative. The specific gravity is above 2.67, as would be expected from a hydrothermal synthetic emerald.The emeralds show a unique chevron-shaped internal growth pattern (figure 3),which has not been observed in any natural emeralds. The emeralds are doped with iron which maslts the fluorescence. The Gem News Editor also has examined some of these Russian synthetic emeralds and his obser-vations support those of Dr. Pough.