COUMTERFEITING 95 



bought some apparently beautiful stone, only to learn when too late that he has acquired 

 some utterly worthless object — perhaps a piece of cleverly prepared bottle-glass! There 

 is still more scope for fraud in mounted stones, the setting of which may be used to conceal 

 all kinds of deceptions. In this connection there will be no harm in repeating the rule, 

 that costly and valuable precious stones should never be purchased in a mounted condition. 



It is not to be denied that certain artifices, which have been already described, amount 

 to an illusion, inasmuch as they make the stone appear better than it actually is. Such 

 artifices, however, cannot be considered fraudulent, since they are openly practised and are 

 known to all persons concerned. Moreover, a lower price will be asked, at least by a 

 respectable dealer, for a stone that has been so treated than for one which stands in no 

 need of artificial improvement. There are indeed many devices, similar to those which 

 have been described, which are adopted quite openly and in all good faith, and are made 

 use of by every fair-dealing jeweller. Such devices, which fall under the head of recognised 

 and allowable manipulation, are not hidden from an intending purchaser, nor is a higher 

 price set on the stone than its natural qualities justify. 



We may contrast with such a transaction one in which a yellowish diamond has 

 received a thin coating of blue colouring-matter, and has then been sold as a colourless, 

 water-clear diamond at a correspondingly high price. There can be no two opinions as to 

 the nature of this latter transaction. There are many cases, however, where it is difficult to 

 draw the line between an artistic device and a fraudulent artifice ; the decision in such cases 

 will turn on the behaviour of the dealer, whether he gives a genuine description to the 

 stone and asks a price corresponding to its natural qualities, or whether, on the other hand, 

 he conceals its deficiencies and demands a correspondingly higher price. 



The buying and selling of precious stones is then, as we have seen, a trade in which 

 fraudulent practices are particularly easy. It would not be practicable to detail every 

 single possibility of fraud, especially as the oldest tricks appear again and again in new 

 dresses. Such frauds as are most frequently practised will be described below : 



1. Substitution of less valuable stones. — This can only be effected when the 

 cheaper stone resembles to a certain extent the more valuable one in colour, lustre, and 

 general appearance, and if possible approaches it also in some essential character, such as 

 specific gravity or hardness. In such cases a little special knowledge of the subject is 

 necessary in order to distinguish between the two stones. In this way a colourless topaz 

 may be substituted for a diamond, since both stones are colourless, and both the lustre and 

 the specific gravity of the topaz approach those of the diamond. To give another example, 

 either colourless zircon or colourless sapphire may be substituted for diamond, and according 

 to Mawe, a London jeweller, these stones at the beginning of the nineteenth century 

 commanded a high price since they were especially suitable for selling as diamonds at a still 

 higher price. The variety of the yellow quartz, known as citrine, is substituted for yellow 

 topaz, and red spinel is often offered for ruby ; other similar cases might be mentioned. 



Some of the stones mentioned above cannot in their natural condition be sold as 

 substitutes for more valuable stones of another kind. Thus hyacinth (zircon) is naturally 

 of a yellowish-red colour, and only becomes colourless and acquires a stronger lustre after it 

 has been heated ; similarly, blue sapphire is rendered colourless by heating. For the same 

 purpose, stones are not only decolourised but also artificially coloured. A fine blue colour 

 is imparted to chalcedony, so that, to a certain extent, it resembles lapis-lazuli and may be 

 used instead of that mineral in cheap jewellery and ornaments of various kinds. 



An experienced eye will usually be able to detect such fraudulent attempts at the first 

 glance, but there are cases in which this is not possible without a more thorough examina- 



