Bonv£.] 2 [January 2. 



NOTES ON GEMS. 



BY THOMAS T. B0TJVE. 



Some experience in the examination and identification of gems 

 within the past year or two leads me to write a few notes upon 

 some of them, believing that what I may communicate will in- 

 terest many and possibly give information that may prove ser- 

 viceable. 



It was not until quite recently that any deep green stones 

 were in general use as jewels, which could be at all compared in 

 beauty with the Emerald. To-day we have two others, the 

 Hidde.jite and the Garnet, and it is not easy to decide which 

 of the three is the most beautiful. Of the Hiddenite a full 

 account has been given in the American Journal of Science, 

 third series, vol. 21, p. 128, and vol. 22, p. 179; and it is, there- 

 fore, unnecessary to say more respecting it, but a few words will 

 be added below suggestive of the modes of distinguishing it from 

 the others. The Garnet, in its red shades, has from remote ages 

 vied with the Emerald in exciting admiration, but had never 

 until within two years appeared before the world as a jewel in 

 the brilliant green hue which now makes it an object of so much 

 attraction. The first stones seen in this country were received 

 by Dr. Leidy, of Philadelphia, and were presented to him by a 

 friend abroad as gems he would highly prize for their unique 

 character. They were called Garnets, and he verified them to 

 be so to his entire satisfaction. Not long after some of the same 

 were received in Boston from a dealer in London under the name 

 of green Hyacinths. There was much doubt respecting their 

 character, nothing having then been learned here of those re- 

 ceived by Dr. Leidy. Subsequently, however, when it was 

 known that stones unquestionably identical were in his possession 

 which he had decided to be Garnets, they became recognized as 

 such. Singularly, however, their true character was again 

 doubted upon optical grounds, as it was thought from im- 

 perfect examination that the crystalline structure was not iso- 

 metric. To convince myself respecting them I broke a small 

 stone in fragments and subjected a particle to blowpipe action. 

 It melted readily and a small, black bead was produced which 

 was magnetic, thus satisfactorily showing, with other evidence, 



