NOME VI. OBSIDIAN. 451 



Iceland ; but he remarks, however, that it differs 

 from it in the polish, which appeared to him 

 more unctuous and less vitreous, besides that in 

 the fractures it had not that waving, striated, 

 scaly appearance, which is proper to the masses 

 of true glass. 



" It must be remembered, however, that the 

 specimens of M. Faujas were none of the best: 

 the pieces, at least, which I collected, took so 

 exquisite a polish and lustre, that I do not be- 

 lieve any kind of artificial glass ever received 

 one more beautiful and brilliant. This glass, Polish, 

 besides, when in the mass, being opake, became 

 a true mirror; and I therefore find no difficulty 

 in believing that the ancient Peruvians used a 

 similar kind of glass, cut and polished, for mir- 

 rors *. This glass likewise could not be broken 

 without exhibiting the undulating scales, lightly 

 striated, which the French vulcanist affirms he 

 could not find in his specimens. While I now 

 write, I have before me a piece with a recent 

 fracture, in which these waves are circular and 

 concentrical, occupying an area of two inches 

 and a half, the common centre of which is the 

 point that received the blow : they resemble in 

 some manner those waves which a stone pro- 



* It wu Mthtt the *tone of the Inca*, a compact pyrites. P. 



geg 



