Chemical Examination of Steinheilite. 77 



Another variety of this mineral from the neighborhood of 

 Dumbarton, in very fine needles, was lately anai^^zed in my 

 laboratory. Its constituents were, 



Silica, _-_--- 



Alumina, ------ 



Lime, -__-_- 



Soda, ------ 



Water, ___--- 



100-88 



It is evident from these different results, that this mineral 

 is apt to be contaminated by some of the kindred species 

 with which it is usually associated. 



27. STEINHEILITE. 



This mineral, which occurs in considerable quantity in Fin- 

 land, was at one time distinguished by the name of blue 

 quartz ; and possesses the characters of quartz so completely, 

 that it would be impossible to know where to place it, without 

 a chemical analysis. It got the name of Steinheilite, from 

 Count Steinheil, who first pointed out the difference between 

 it and quartz. It occurs in a copper mine at Orrijerfwi, in 

 the government of Tawestihus. Professor Gadolin analyzed 

 it, and announced the existt-nce of a new mineral substance in 

 it. Stromeyer repeated this analysis, and published the re- 

 sults in the first volume of his Unlersuchungen. He found 

 it composed of, 



Silica, ----- 492487 



Alumina, ----- 32*0742 

 Magnesia, ----- II -5 J 92 



Protoxide of iron, - - - - 6-9682 



Deutoxide of manganese, - - - 0-6385 



99-4488 



