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PUKHRAJ

PUKHRAJ have surged in popularity in recent years (figure l), which has prompted further study into their properties and, especially, the effects of treatment by heat or irradiation. An important problem is the distinction between yellow sapphires that are color stable and those that fade under normal conditions. At present, the only practical way for the gemologist to separate these two materials is by an extended exposure to light or by some sort of heating test. Webster and Anderson (1983) suggest that three hours in bright sunlight or a few minutes of heating at 230Â° will fade (and thus identify) irradiated Sri Lanka material.