1 20 Elements of Mineralogy. 



Mr. Achard, 60 of argill, 21,66 of filex, 



8,33 of calcareous Earth, and 5 of iron. 



It was antiently found in Egypt 9 now 

 chiefly in Peru. 



Chryfolite^ or Beryl, is of a light yellowim 

 green ; it melts per fe into a flag ; it is fofter 

 than cryftal; it yields only to borax and 

 microcofmic fait, and is icarcely affected by 

 alkalis : when ready to melt it becomes phof- 

 phorefcent, 



Aqua Marine f augites) is of a bluim green \ 

 it melts per fe by the blow-pipe. 



IV. VARIETY, * 

 Blue, 



Sapphire. 



Its colour is fky blue ; its texture foliace-* 

 ous; its form hexangular or polyangular 

 prifms or parallelipeds ; its fpecific gravity 

 from 3,78 to 3,994 ; the oriental preferves 

 its colour in a porcelain heat, and will not 

 TL\t\iperfe 9 but that of Brazil lofes its colour; 

 it is affected by fluxes as the other varieties. 



Mr. Bergman found 100 parts of this ftone 

 to contain 58 of argill, 35 of filex, 5 of 



