Turquoises
Turquoises should be blue to be of any value. Bluish green, green, and a dull, dirty green are all inferior qualities. The inclusion of matrix (black or brown) and other foreign matter which is often seen on the surface of a stone is also a detraction. Really fine blue turquoises of size are scarce, yet $2.80 (20/-) a carat would be a high price for such stones. Very good imitations of this stone are made from blue glass, blue china, and blue enamel.
Good quality lapis lazuli is not uncommon, but it is a stone which is not much used in jewelry. One should look for a deep blue, unspoiled by white or gray streaks and patches. The included iron pyrites as a few specks is no great deterrent to appearance or value. There is little else which can be confused with lapis lazuli. Glass, suitably colored is the best imitation, the commercial Swiss lapis being obviously different to the naked eye.
Fine jade (jadeite) is very scarce, although inferior quality pieces abound. These latter are of little value, as is also the greenstone (New Zealand) variety. Fine jade is a deep green, full of life, and almost like an emerald except that it is translucent and not transparent. It should be free from blemishes, which are usually of a white or gray character, and it should contain no cracks. The colored varieties of jadeite, the pinks, mauves, reds, and browns, are generally of a pale shade, and these are not of great value. Fine pieces of jade realize high prices, although their market is a restricted one. Individual collectors and connoisseurs are the chief buyers of such stones.