TESTING FAKE GEMS

Evening Post, Volume 137, Issue CXI, 10 June 1926, Page 14

TESTING FAKE GEMS

Jewel forgers have become so clever that a special gem-testing institute has been established in Vienna (says "Popular Mechanics"), and similar studies are being carried on in Great Britain to detect imitations. Imitation diamonds are numerous, and it is possible to make real ones in the laboratory, but the cost of the process is about 200,000 dollars a carat, while natural ones can bo purchased at from 100 dollars to 300 dollars a carat. Eubies can be made by laboratory methods in about six hours, and some of them are so nearly like the real stones that other tests than with the eyes are necessary to distinguish them. While the synthetic emerald has brilliance and realistic colour, it usually can bo told from a genuine one with little difficulty. They are often built up in three parts, which are fastened by invisible cement. The.top and the bottom part may be glass crystals cut in many facets with a thin shaving of a real emerald between them to give tho colour. Others may have a slight cavity between tho two crystals which is filled with a green liquid. Both imitations are. easily detected by submerging the stone in a certain kind of oil and holding up to the light.