PHYSIOGRAPHY. 231 



Glauber Salt. 



Lustre vitreous. Color white. Streak white. Trans- 

 parent to opake. 



Sectile. Hardness = 1-5 ... 2-0. Sp. gr. = 1-481. 

 Taste cool, then feebly saline and bitter. 



1. It is easily soluble in water, but readily falls into powder on being 

 exposed to the air. 



2. Analysis. 

 By REUSS. 

 Sulphate j " ^ 67-024 



Carbonate V of soda ) 16-333 



Muriate ) C 11-000 



Muriate of lime 5 643 



3. Glauber Salt is found accompanying Common Salt and Epsom Salt, 

 or as an efflorescence, upon the soil, and on several rocks ; also on the 

 shores of salt lakes, and in some mineral springs. 



4. It occurs in the neighborhood of Ausser, Ischel, and Hallstadt in 

 Austria, at Hallein in Salzburg, in Hungary, in Switzerland; also in 

 Italy and Spain, and the Sandwich Islands. 



GLAUCOLITE. 



Massive. Cleavage parallel with a rhombic prism of 143 30 ; , 

 nearly. Fracture splintery, or uneven. 



Lustre vitreous. Color lavender-blue, to green. Translucent. 

 Hardness = 5-5. Sp. gr. = 2 7 . . . 2-9. 



1. Fusible with difficulty before the blow-pipe, into a blebby white 

 glass ; but is soluble in borax and salt of phosphorus. 



2. Analysis. 

 By BERGMANS. . 



Silica 54-58 



Alumina . . . . . 29-77 



Lime 11-08 



Potash 4-57 



3. It is found in compact Feldspar and granular limestone, with Talc, 

 in the granitic mountains, upon the borders of the Sliudiauka, which 

 empties into lake Baikal. 



4. With the exception of the cleavage, the foregoing description would 

 apply to some of the varieties of Scapolite. 



