IMITATION JEWELS.

Otago Witness, Issue 2728, 27 June 1906, Page 78

IMITATION JEWELS.

Of all the remarkable trades which in ■ the last 10 years have developed from ' the stage of crndity to the rank of an exact science, none, perhaps, is more remarkable in its peculiar character than the , trick of preparing imitation gems. i Time was (says the New York Journal) when the expert dealer in genuine diamonds or rubies had good reason for his boast that no imitation gem, however perfect its preparation, could deceive the J eye of the expert or even a lay judge for . even a minute, and that paste under certain lights invariably betrayed its I jiresence. I But in the last decade the preparation j of finely-cut paste stones, especially in ' Fiance, the Netherlands, and Amsterdam, where nearly the whole of the diamond I cutting is done, has reached an altitude of perfection provocative of every 6pecies ' of fraud. A microscopic examination by an expert is necessary in order to detect the difference between a diamond worth £100 and the paste duplicate worth £4. , "A paste stone properly prepared exhibits the same lustre, the same prismatic beauty, as a diamond of the first^water," said one of the most famous experts. "In these days we are compelled to apply every chemical 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 em- ' ployed ensures an equal degree of clear- I ness, depth, and transparency. It is pos- i sible, too, to imitate colour so that a ruby, emerald, or sapphire is undistinguishable from the real jewel." A combination of red lead, rock crystal, potassium, carbonate borax, and white, arsenic constitute the material from which ! the paste is made. According to experts, an increase in the amount of lead used in the production of the "paste" will produce a corresponding increase in brilliancy and play of colour. "Now, while il is possible to produce a paste gem which will maintain its brilliancy," said the expert, "there is one difficulty which the manufacturers have not yet surmounted. The paste gem must always be of softer material than the genuine diamond. "From the preparation of stones avowedly paste to actual fraud by tho substitution of paste for real gems is but ( a step. In India, in Turkey, and in j St. Petersburg are many merchants who charge a large sum for a stone repre- j sented to be a diamond, but which on J examination by an expert is seen to be merely a piece of a glass bottle." \ Probably, however, the "doublet" pro- J vides the most popular form of fraud. The doublet 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 j the imitation half partakes of something of the fire and brilliancy of the genuine- ! 6tone. Coloured stones are imitated by ! means of rock crystal, ground to resemblethe usual appearance of the particular, stone to be imitated, but with a hollow cavity inside filled with coloured water. ' A Dlate of rock crj^sta^ cleverly fitted ia,

produces a fine ruby, sapphire, emerald, or amethyst difficult to distinguish from the genuine stone. "Whenever you see a fine-looking peor! in the hair of a beautiful woman." added ! the expert, in conclusion, "warn your wife to pause before she envies the wearer. For all that sha or anyone else, save an old expert of 40 years' experience in tfhe business can tell, the seemingly priceless pearl may be so much opaline treated carefully with hydrofluoric Acid, and worth about £10. Very gqod imitation* of ihe genuine pearl are prcduced from highlrpoHshed mother-of-pearl.