171 



'I'lic blue eolur \va>; ulitaiued only at'ter luu.u study ami t'XiK'i'imunta- 

 lidH (in the part of Verneuil and an American assistant. Mr. 1. 11. Levin. 

 Tlicy t'oimd tliat the attempt to blend (•(il)alt as a colorant failed, the cobalt 

 volatilizing or else floating out when the bnule cooled. Picard. in 1U07, 

 and Louis Paris, in 1908, succeeded in i,'ctting boules of a tine blue color 

 by blending magnesia or lime with tlu' alumina and adding cobalt. They 

 were, however, not true sapphires. Some of these boules were sent to a 

 friend of mine, an enthusiastic gem collector. INIr. Wm. IL Iluse, of Manches- 

 ter, N. PL, and at his request I tested them and found that they were too 

 low in specific gravity, too soft, and their system of crystaliization was the 

 regular or cubic system. They were singly refracting and showed no 

 dii-hroism. They were, in fact, artificial spinels. Their color also was 

 of too piercing a blue. This was afterwards remedied by adding a trace 

 of chromium oxide, but then the color as seen by artificial light was 

 unnatural. 



In January, 1910, Verneuil and Levin succeeded in obtaining true sap- 

 phires by adding to 98% of alumina 'I'^r of a mixture of ferric oxide and 

 titanium oxide and keei)ing the boule in a reducing atmosi)here. A paper 

 in regard to these bonles \^-as read by ^'e^neuiI in 1910 before the French 

 Academy. It quoted M. Wyrouboff. who examined them before the.v were 

 submitted to the Academy. He said of them : "They take the form of 

 a single crystal which is uniaxial, optically negative and little birefractive, 

 consequently having all the optical j)roperties of the natural sapphires. 

 Furthermore, their comiiosition and crystalline constructidu must evidently 

 lead to the conclusion that these stones are in every other resp-ect iden- 

 tical with the natural sapphires. They even show the parti-colored effects 

 like the natural stones." 



In connection with this report of Wyrouboff I will quote here the report 

 of Bauer, the great German gem expert, on the synthetic ruby boules. 

 In a paiier read before the German Chemical Society of Frankfort, A. M. 

 Bauer says: "The rub.v bulb, in s])ite of its romid shape, shows a true 

 crystalline formation. In specific wi'ight. in hardness, as well as in 

 all the optical properties, it is identical with the natural stone: in color 

 and brilliancy it vies with the best spec-imens from the Orient." 



Some of the new blue sa]>phires were sent to this country and were 

 submitted to Prof. Alfred Moses of Columbia University, who says: "The 

 chemical analysis shows the material submitted to be nearly pure alumina 

 with, however, a measurable quantity of titanic oxide. The crystallo- 



