As the colors green and red are the national colors of Russia, and the date of discovery of this stone in Russia occurred on the Emperor’s birthday, the name alexandrite was given to this species of chrysoberyl. The alexandrite is found in large pieces, but is nearly always flawed and cracked. This is a much-sought-after gem stone, and specimens of from one to five carats command good prices. Up to the present time, however, good alexandrites have been rare, and the demand has always exceeded the supply. Cat’s-eyes and cymophanes are found in Brazil in alluvial deposits of rivers, and consequently in rolled and rubbed masses. Chrysoberyls are also found in Russia, Germany, America, Borneo, Pegu, and Moravia. Chrysolites and topazes are sometimes passed off for chrysoberyls. The chrysolite is, however, lighter and softer, while the topaz becomes electric from heating, and is softer. Quartz cat’s-eyes, which are mistaken for chrysoberyl or Oriental cat’s-eyes, have a specific gravity of about 2.65, hardness of 6 to 6.5, and are soluble in fluoric acid, besides melting with soda into a clear glass. They lack the bright, hard polish of the chrysoberyl cat’s-eye, and there should be no difficulty in discovering the difference between the gem and the inferior stone. ZIRCON. The zircon, hyacinth, jacinth, or jargoon belong to the tetragonal system of crystallization. The cleavage is imperfect, fracture conchoidal, and specific gravity 4.4 to 4.7, the stone being much heavier than any other gems. Its hardness is 7.5 and lustre vitreous to adamantine, and refraction double to a high degree. The zircon is phosphorescent when heated; before the blow-pipe it is infusible, but loses its color; and with borax it melts into a transparent glass. Sulphuric acid affects this gem after long maceration. The composition of the zircon is: zirconia, 66.3; silica, 33.7; with a trace of peroxide of iron. Under the microscope, the texture of these gems presents a watery appearance, called by the French _ratiné_, and which looks like a liqueur poured into water. This is a strong distinguishing point in the zircon. The zircon, hyacinth, jargoon, and jacinth are the same gems but of different colors. The brown, violet, and green colors are known as zircons, the red as hyacinth, the yellow as jacinth, and the grayish-white and white as jargoons. The jargoon has often been palmed off as a diamond because of its transparent color and adamantine lustre. The zircon is found in Ceylon, Germany, France, Bohemia, America, and in fact in nearly all parts of the earth, as many as 120 localities having been noted where specimens of the mineral have been discovered. The zircon can be distinguished from the garnet by its peculiar diamond-like brilliancy and its specific gravity. TURQUOIS. The turquois is never found in crystals, but in reniform or stalactitic masses. The color varies from pea- and apple-green to greenish-blue, sky-blue and dark-blue.