A mineral ranked among the precious stones. It is found in Scotland, Cornwall, Saxony, Siberia, the United States, Mexico, and Brazil. The finest varieties are found in Brazil and the Ural Mountains, and are of a deep yellow tint, while those of Siberia are blue, the other colors found being white and green. They are frequently found in the cavities of granite rocks, and consist of a silicate of alumina in which fluorine takes the place of oxygen. It is next to the sapphire in hardness. The topaz of the ancients, obtained from Topazos, an island in the Red Sea, was chrysolite.