BERYL. 151 



The mass is softened with water, dissolved in 

 hydrochloric acid, the silica rendered insoluble by 

 evaporation, as in the analysis of feldspar; the dry 

 mass moistened with hydrochloric acid, and a little 

 nitric acid, warmed, diluted, and the silicic acid 

 filtered off. 



The solution is then neutralized by carbonate of 

 soda, acetate of soda added and heated to boiling. 

 The iron and alumina are precipitated, and may be 

 separated by hyposulphite of soda, as in No. 21. 



The filtrate, which contains acetates of lime, mag- 

 nesia, and manganese is saturated while hot with 

 chlorine gas, which precipitates the manganese. After 

 ignition it is weighed as MnO, Mn 2 O 3 . If the fluid 

 has been colored red by the formation of perman- 

 ganic acid, ammonia is added, and then boiled until 

 the color is destroyed. The lime and magnesia are 

 separated in the filtrate as in No. 12. 



These and all similar minerals, not attacked by hy- 

 drochloric acid, may likewise be conveniently decom- 

 posed by hydrofluoric acid; in which case, however, 

 the silica must be determined by loss. (See Ortho- 

 clase.) 



82. BERYL. 

 Be/),, 2 SiO 2 + A1 2 3 , 2 Si0 2 . 



The very finely-powdered mineral, previously well 

 dried, is fused in a platinum crucible with 4 times its 

 weight of carbonate of potassa and soda (see No. 10) ; 

 the mass is softened with water, digested with excess 

 of hydrochloric acid until the decomposition is com- 

 plete, and evaporated to perfect dry ness to render the 

 silica insoluble. The residue is moistened with hydro- 

 chloric acid, and treated with warm water; the silica 



