THE PRODUCTION AND IDENTIFICATION OF ARTIFICIAL 

 PRECIOUS STONES. 1 



[With 3 plates.] 



By Noel Heaton, B. Sc, F. C. S. 



During recent years the production of artificial stones on a commer- 

 cial scale has become an accomplished fact, and a great many miscon- 

 ceptions and misleading statements have been made as to the relation 

 which these productions bear to natural products on the one hand and 

 imitations gems on the other. It may therefore be of some use to 

 make the matter clear by describing as fully as circumstances permit 

 what has been done in this direction and what has not been done; 

 what is practicable and what is impracticable in the present state of 

 our knowledge. 



I suppose there are few subjects of interest from so many points of 

 view as that of precious stones. The beauty and rarity of fine speci- 

 mens has from time immemorial rendered them the most treasured of 

 possessions. With the romance that surrounds this aspect of the 

 question we have nothing whatever to do to-night, except to bear in 

 mind that on account of their great value men have for centuries 

 strained their ingenuity to solve the mystery that surrounds the origin 

 of such stones, and amass wealth by producing them at will instead of 

 by the laborious and highly speculative process of digging for them 

 in the earth. 



Until the development of modern science and accurate methods of 

 investigation this problem resisted all attempts at solution, and it is, 

 in fact, only within the last few years that the artificial production of 

 any species of gem on a commercial scale has become practicable. 



Of course, one can cut the Gordian knot by preparing a colorable 

 imitation of the real thing, but that is quite another matter, and I want 

 to make it quite clear at this point that I propose to limit the term "arti- 

 ficial" to such productions as possess the same chemical composition 

 and physicial constants as the natural stones, differing from them only 

 in minute details consequent upon their being produced in the labora- 



i Read before the Royal Society of Arts, Wednesday, April 26, 1911. Reprinted by permission from 

 Journal of the Royal Society of Arts, London, No. 3049, Vol. 59, Apr. 28, 1911. 



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