Silk
“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.