The daily morning journal and courier., 1906-04-07
HOW THE UNwARY ARE DupEn

The passion for precious stonas
 which has reigned in the minds of
 men and women almost from tima i'm
 memorial has, of course, given rise to
 much counterfeiting of the more valu-
 able stones. All are more or less with
 the cheap glass limitations where the
 worthlessness of the article is so an-
 parent. that. there, is no suggestion of fraud Few, however realize to what
 an extent skilled fraud exists in this
 trade, more especially on the Continent
 where much of the diamond cutting is
 done. The manufacture of imitation gems of specially prepared glass is quite an important industry
 It is now possible to produce in paste an imitation of almost every precious stone which is capable of deceivig the 1 eyes of all but the most expert Not only is there superficial resemblance. but skillfully prepared paste" stone exhibits the same luster and high index or refraction and dispersion as would a diamond of the first water The purity of the materials employed is such that an equal degree of clearness and transparency is given to the imita- tion as is found in the genuine stone. Color is initiated also that the ruby, emerald, sapphire or other gem made of glass Is practically indistinguishable from the real jewell, which may have cost hundreds of pounds.
 The material of which these iinita- l ton stones are made Is now a ''strass." This is made according to | different recipes, but usually include i red lead, rock crystal, potassium, car- bonate, borax and white arsenic. The 1 greater the amount of lead used in the production of the paste" the greater will be be the brilliancy and play of prlsmatic colors in the finished stone, and at the same time the higher will be it's specific gravity On the other hand,
 the stone loses it hardens what 1t gains in brilliance. An old time but still ser viceable, rough and ready test for d stone is to see whether it will stretch or cut window glass, which is as a rule, harder than most imitation stones.
 It must not be imagnined that these close limitations of the real diamond or other stone can be produced cheaply | This is far from the case. A large capi- tai is required in the manufacture, and 1 the high degree of purity is necessary in all the materials employed necessi- tates an amount of care, and incident
 ally waste, which Is exceedingly ex- 1 pensive. Moreover, the imitation have to be cut and finished in precisely the same manner as the real stones, and l this is perhaps the most expensive part l of the procedure.
 i Another method of deceiving the unwary purchaser of precious stones l which have been ''faked" in some way l to make them appear more valuable than they really are. A devive corn- monly practiced is that of cerrienting two stones so that they appear to be- one large one At first sight there does not seem sto.l be any object in such a proceeding, but diamonds increase very mucfar in value,if they are large. For instance, while G10 would be a very fair for diamond weighing one carat, l R150 might be paid for a five carat stone of the same water.
 Eastern jewellers are particularly skill full in this direction. An Indian dealer will think nothing of selling for a., large sum beautiful stone, which on ex- imitation by an expert, perhaps to be perhaps, not only skillfully piece of bottle glass. It is not, of course, claimed that there Is necessary any thing fraudulent in the skillful pre- paration of imitation stones to resemble more valuable gems. Many of the most reputable jewellers deal in these stones, charging price for which no one would expect to procure the genu- inc article. So long as the customer Is taken into the jewellers confidence here is nothing to object to in the bargain A yellowish red stone called hyaninth and also the blue sapphire lose their color on being heated, and may then be set as diamonds. Similarly, variuos stones may be colored in such amanner as to make them resemble others of a higher value, 4e
 A favorite method of preparing pre- clous stones so as to make them appear more valuable than they really are is by means of the "doublet." This may be- done at the request of customer who wishes to make finer show than he or she would otherwise be able to do, or it may be practiced by an un- scrupulous dealer to deceive the un- wary. It is said that a great deal of this work is done on the continent. A doublet consists of an upper part, which is genuine, secured to lower part of some less valuable stone or of glass. The two parts are cemented together and ground so as to leave no trace of the union. The fire of the, stone as seen through the imitation, which is itself made of some paste with a high degree of brilliancy. If the doublet is secured by cement the. two portions will fall apart on immersion in hot water. When the base Is com- posed of glass, however it is usually fused to the upper and genuine half So that the fraud Is very difficult to de- tect
 Another way of preparing doublet is to make the upper portion of rock crystal some similar transparent nla- terial with a high degree of hardness, and the lower portion of tinted glass, which seems to impart its color to. the whole The fraud may be to fife light; as 1t is usually employed in making up jewelry with closed settings the pur- chaser has no opportunity of making this test.
 Finally, colored stones are initiated in nartieularlv ingenious WAY by