chrysoberyl (krĭsˈəbĕrˌĭl) [key] [Gr., = golden beryl], a beryllium aluminate used as a gem. It has a vitreous luster and is transparent to translucent. The more valuable cat's-eye is a variety of chrysoberyl. Another variety, alexandrite, was first discovered in the Ural Mts. of Russia, on the birthday of Czar Alexander II, for whom it was named. It is remarkable in that it is green by daylight and raspberry red under artificial light. It was popular in imperial Russia, both because of its association with the czar and because red and green were the colors of the empire. It is now found chiefly in Sri Lanka and Brazil.
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