482 



MEASUREMENTS OF CRYSTALS. 



aUARTZ. (Continued.) 



Figs. 167, 168 and 173, twin crystals. 

 Figs. 174, 175. 



P ono 128°20' 



Fig. 181. 

 P on a; 

 r on X 

 X on z 



.... 148°42' 

 .... 167 56 

 125 11 



