321 



[Jackson. 



COMPOSITION. 

 NO. I. NO. n. 



Alumina . . . 80.75 83.00 



Water .... 14.75 14,80 



Ox. of Titanium ) . f-^ „ „„. 



and Ox. of Iron. } ^''^^ 3.00 



100.00 100.80 



Alumina determined by difference in No. 1. 



Margarite. 



Analysed by John C. Jackson in my Laboratory. 

 Hardness 3.5 to 4. Specific Gravity 3.03. 



COMPOSITION. 



Silica 29.84 



Alumina 53.84 



Lime 10.38 



Magnesia • . . . 0.24 



Soda and Potash 2.46 



Peroxide of Iron 0.30 



Water 1.32 



98.38 

 Prof. J. Lawrence Smith says he has detected Lithia among the 

 Alkalies of this mineral, which would seem to give it a place be- 

 tween the jSlicas and Lepidolite, the latter containing Lithia as its 

 chief alkali. 



Margarite is extremely abundant in the Chester Emery mine, and 

 the specimens are the most beautiful that have thus far been discov- 

 ered in any part of the world. 



Clinochlore or Chloritoid of the Chester Emery Mine. 



The specimens analysed contained microscopic grains of magnetic 

 iron ore which could not be wholly separated mechanically, hence 

 the proportion of oxide of iron in the analysis is too great for pure 

 Chloritoid. This mineral is distinct from Chlorite on account of a de- 

 ficiency of the essential proportions of Magnesia in that mineral. 



CLINOCHLORE OF CHESTER. 



Mn. 02= 



