PHYSIOGRAPHY. 



Polyhallite Polymignite. 



115 



1. In the flame of a candle, it melts into an opake globule, and is 

 readily dissolved in water, the solution letting fall a precipitate of sul- 

 phate of lime. 



2. Analysis. 

 By BERTHIER. 



from Vic. 



Crystallized. I 

 Sulphate of lime 

 Sulphate of soda 

 Sulphate of mang. - 

 Sulphate of magnesia 

 Chloride of sodium - 

 Alumina and ox. iron 

 Loss by calcination - 



By STROMEYER. 



from Ischel. 



Anhydrous sulphate of litne .... 22-2184 



Anhydrous sulphate of potash - 27-6347 



Anhydrous sulphate of magnesia ... - 20-0347 

 Anhydrous sulphate of iron - - - 0-2927 



Hydrous sulphate of lime .... 28-4580 



Chloride of sodium .... 0-1910 



Chloride of magnesium .... 00100 



Peroxide of iron .... 0-1920 



3. It occurs at Berchlesgaden and Ischel, along with Common Salt, 

 Gypsum and Anhydrite ; also in the salt mines of Vic in Lorraine. 



POLYMIGNITE. Melanous E ruth rone-Ore. 



Primary form. Right rhombic prism. 



Secondary form. Primary, having the lateral edges 

 deeply truncated, or slightly bevelled, and terminated by 

 four-sided pyramids, which, viewed as an octahedron with 

 a rhombic base, have angles of 136 30' and 116 30'. 



