248 



N. L. Bow en — The Ternary System 







Table 



VI. 





Composition 



Extinction 



Angle cACon 010 



MgSi0 3 



100 f 







22° 



(C 



81 # 







26° 



(( 



63 f 







30° 



a 



53'5# 







31-5° 



u 



44 i 







34° 



a 



25-5$ 







30° 



Diopsid* 





Fig. 



21. 



37-5° 



38*5° 



i 











%A. 



°-^ 











30 



9ft 























22 























DI0PSIDE 



20 40 60 



WT PER CENT 



Fig. 21. Extinction Angles of Pyroxene Series 



3OCLIN0-ENSTATITE 



Fig. 22. 



38 



A 











d™ -J 





^""^^ 





1 



30 























22 





















B 



CaM g S, 2 6 



20 



40 



60 80 



MOL 



PERCENT 



ACB= CALCULATED CURVE 

 O = OBSERVED VALUES 



M g S,0 3 



Fig. 22. Extinction Angles of Pyroxene Series. 



