ANALYSES OF MINERALS. 383 



Lamellar talc from St. Gothard *. Lamellar talc. 



Silex 62 



Magnesia 30*50 



Oxide of iron 2*50 



Potash 2*75 



Loss in roasting 0-50 



98*25 



Common mica from Zinnwalde +. Common mica. 



Silex 47 



Alumine 20 



Oxide of iron 15*50 



manganese 1*75 



Potash 14*50 



98*75 



Muscovy glass, or mica in large laminae from Siberia + , 



Silex 48 



Alumine 34*25 



Oxide of iron 4*50 



Magnesia.... 0*50 



Potash 8-75 



Loss in roasting 1*25 



97*25 



Black mica from Siberia §. Black mical 



Silex 42*5 



Alumine , 11*5 



Magnesia 9 



Oxide of iron 22 



. manganese ... 2 



Potash 10 



Loss in roasting 1 



97 



Mica in large 



laminae. 



* See Journ. vol. xxvii, p. 226. f lb. p. 227. 



X lb. p. 228. § lb. p. 230. 



Black 



