Chemical Examination of American Minerals. 40 



Precious Serpentine. Picrolite. 



Silica, 43-07 41 -600 40-04 



Magnesia, 40-37 37-159 3S-80 



Lime, 0-50 



Alumina, 0-25 



Protoxide of iron, 1-17 4-046 8-28 



Deutoxide of manganese a trace, 2-247 



Water, 12-45* 14-723 9-08 



Carbonic acid. 4-70 



07-8r^ 99-835t 100-9J 



The mineral which I am going to describe, is obviously a 

 specimen of precious serpentine. I got it from Mr. Nuttall, 

 among a collection of North American minerals. It was 

 found at Easton, in Pennsylvania. 



The color was yellow, with a slight shade of green. It 

 appeared when examined by a microscope, to be composed 

 of a congeries of s* ini-transparent grains. 



It was easily scratched by a knife, but not by fluor-spar. 



Its specific gravity was at first 2-53 ; but after digestion in 

 muriatic acid, to remove some calcareous spar with wiiich it 

 was conta;Tiinated, the specific gravity was reduced to 3-39. 



The constituents were found to be, 



Silica, . - _ - - 



Magnesia, - - - - - 



Peroxide of iron, _ _ - - 

 Water, 



99-30 



* Hising^er, Afhandlingar, iv. 341. 

 f Stromeyer, Uulersucli, p. 370. 

 \ Alraroth. AfhandliDsyar, vi. 263. 

 Vol- III. 7 



