HOW IMITATION JEWELS ARE MADE.

Wairarapa Age, Volume XXVIX, Issue 8117, 11 April 1906, Page 7

HOW IMITATION JEWELS ARE MADE.

Of all the remarkable trades which in the last ten years have developed from the stage of crudity to the rank of au exact science, none, perhaps, ia more remarkable in its peculiat character than tbo trick of preparing imitation gems. Time waa when the expert dealer in genuine diamonds or rubies had good reason for his boast that no imitation gem, however perfect its preparation, oould deceive the eye o* au expert or even a lay judge for an instant, and that paste under Certain lights invariably betrayed its presence. But in the last doctide the prepa- . ration of Bnely cut paste atones, especially in Franoe, the Motherlands, and Amsterdam, whore nearly the whole of the diamoud cutting is done, has reached an altitude of perfection provooative of every species of fraud. A microscopic examination by an expert is necessary in order to detect the difference between a diamond worth 500 dollars and the paste duplionte worth 20 dollars. "A paste stone- properly prepared exhibits the same lustre, tha same Driamatio beauty as a diamond cf the first water," said one of the moat famous among the Maiden lane ex> perts. "In these days wo are compelled to apply every cbemioal test in order to distinguish the difference between fine paste and a pure white flawless diamond of the first water. The purity of the materials employed insures an equal degree of clearness, depth and transparency. It is possible, too, to imitate colour so that a ruby, emerpld, or sapphire is indistinguishable from the real jewel." A combination of red lead, rock crystal, potassium, oarbonate borax. ■ and white arsenic constitute the material from which the paste is made. According to tho New York exoerts an increase in tho amount of lead used in the prod notion of "paste" will produce a corresponding increase in brilliancy and play of colour. "Now, while it is possible to produce a paste gem which will maintain its brilliancy," said the expeit, "there is one difficulty which the manufacturers have not yet surmounted. The paste gem mast always be ofsofter material than the genuine diamocd. the preparation of stones avowedly paste to actual fraud by the substitution of pußte for real gems is bat a step. In India, in Turkey, and in St. Petersburg are many merchants who charge a large sum for a alone represented to be a diamond, bat which on examination by an expert is seen to be merely a piece of glass bottle." "Probaby, however, the 'doublet' provides the most popular form of fraud. The doubet consists of an upper part, which is genuine, secured to a lower part of glass. Skilfully cemented together, the two parts leave no trace of the union, and the imitation half partakes of something of the fire and brilliancy of the genuine stone. Coloured stones are imitated by means of rock costal, ground to resemble the usual appearanoe of the particular stone to be imitated, hut with a hollow cavity inside filled with coloured water. A plate of rook crystal, cleverly fitted in it, produces a ruby, sapDhire, emerald or amethyst difficult to distinguish from the genuine stom. "Whenever you Bee a fine (looking pearl in the hair of a beautiful woman," added the expert in conclusion "warn your wife to pause before she envies the vearer. For all that she or any one else, save an old expert of forty years' experience in the business, can tell,, the seeming priceless pearl may be bo muoh opaline, treated oarefully with hydrofluoric acid, and worth about 50 dollars. Very good imitations of the genuine pearl are produced from highly polished mother of pearl.