1906] 



TRAVIS— PYRITE FROM CORNWALL. 



143 



Fig. 7. Type IL Fig. 8. Type IL 



The observations determining these forms are as follows : 

 (321) was- a face commonly observed. Some of the measure- 

 ments are : 



321A111. 



Measured 22° 14' (Crystal 22) 



Measured 22" 13' ■ (Crystal 22) 



Measured 22** 10' 



etc. 

 Calculated 22" 12^' 



showing the degree of accuracy that may be expected in this type. 

 (753)) a- new form, was observed on crystals 23, 26 and 27, — 



753A"i- 



Measured 18" 05 (Crystal 23) 



Measured ,. . 17" 58' (Crystal 26) 



Calculated 18* osYz 



753 A 321. 



Measured 4° 05 (Crystal 27) 



Calculated 4° 07' 



It is almost unnecessary to state that the above, as well as all 

 other diploids observed on this type, were found to be sensibly in the 

 zone of (hi) and (210), so that one angle from the octahedron 

 determines them. 



