mygemologists.com

“Silk” is a fault, as are also fissures and cracks. They are by no means uncommon. Facets should be examined for nicks and cracks; they are often seen in old stones. Surface scratches due to wear can be polished out, and sometimes old stones with irregular facets can be recut to advantage. Proportion in width and depth should be good. Blackish stones, generally of Australian origin, are not worth much. The bright but pale stones are of more value, but these do not approach the prices reached by Cashmere, Burma, or Siam stones. Most of the fine Cashmere stones are now to be found only in old jewelry.

Sizes from three to five carats are ideal for ring stones. Large stones, up to fifty carats, are sometimes seen, but these are exceptions, particularly if they are of fine quality, and they can realize $560 (£200) a carat. The medium size stones are worth about $56 (£20) to $210 (£75) a carat if of good quality and color. Those of one to three carats obtain about $56 (£20) to $112 (£40) a carat, if fine.

Good imitations of amethyst have been made in paste, and some of these may be found in old jewelry. It is worth while applying a simple test, such as that of hardness, if there is any doubt.

Kunzite, to be of value, should be flawless and of a decidedly pinkish shade. Small specimens are of little value since their color is almost always pale. Sphene is not often seen in jewelry; it is rather soft, and cut stones soon become scratched in wear. The better specimens are very bright, and they can realize $140 (£50) a carat or more.

Of the many other uncommon jewel stones which we have mentioned, there is not much to add here, except to say that their occurrence in jewelry is rare and comparatively isolated. A jeweler may be in business for many years before he encounters scapolite, or phenakite, or epidote in a mounted article; such stones are for those who take more than an average interest in the precious minerals, the collectors and the connoisseurs. Moreover, such stones have no precise market value, any more than have the single specimens of “new” minerals which are found from time to time. We are, of course, considering jewel stones from a purely commercial point of view in this chapter, but there are many to whom this angle is of first consideration and importance. The scientist is not often concerned with supply, demand, and price fluctuations.