Precious Stones & Gems: Chrysoberyl, the Oriental Chrysolite of Lapidaries Page 278





	HERE is probably no stone the composition of which has been given with so much variation as this. There is, however, reason to believe that chemists have frequently analysed different stones, and confounded them under one term. The true Chrysoberyl, as known to us to-day, is essentially a compound of alumina and glucina, with varying proportions of oxide of iron. There are three varieties of this stone—the Chrysoberyl, the Cymophane or true Oriental Cat's Eye, and the Alexandrite. The colours of the Chrysoberyl range from light asparagus green, golden yellow, brownish yellow, and goldeir brown, to columbine red. The crystalline, forms of the Chrysoberyl belong to the rhombic system. , It is usually found as rolled pebbles in the same sands as those which furnish crystals of Topaz and Corundum. Crystals of great beauty are found in the Emerald mines of Takowaia, east of the Catherine Mountains in the Ural. It is brittle, transparent, or translucent, and possesses in a high "degree the power of double refraction, and a vitreous and oily lustre. A peculiar bluish opalesence, in the inner part of the stone, is sometimes seen. It is interesting to trace the history of our knowledge of the chemical constitution of Chrysoberyl. Klaproth