J 6 



A. J. Moses — Crystallization of Luzonite. 



aa c = 001, the consideration of the angles in the vertical zone 

 suggested an orientation for comparison with the common 



forms of enargite as follows : 



Enargite 

 Form. Face. 



C=001 

 m — 110 



120 

 130 



Crystal No. 1. 

 Signal. Measured 



Fair 



Double 



Blurred 



Faii- 

 Double 



48° 57' 

 48° 58' 

 48° 30' 



20° 22' 

 19° 17' 



0° 5' 



Crystal No. 2. 

 Face. Signal. Measured (j>. 



1 Fair 



2 Double 49° 02' 

 5 Fair 48° 44' 



Faint 



31° 44' 



22' 

 5' 



Crystal No. 2 (p. 

 48° 56' 

 31° 44' 



89° 46' 

 common forms of 



6=010 



«=100 . ..... 7 Double 89° 46' 



hOl . curved Series 90° 0' 



The comparison of the averaged angles is : 



Enargite (p. Crystal No. 1 



mr=48° 59' 47" 48° 48' 



h=z29° 54' 13" ._._ 



/=20° 58' 38" 20 



b= 0° 



a=90° 



That is, all the angles are those of the 

 enargite within the limits of accuracy that the measurement 

 of minute crystals with rather dull c faces and somewhat 

 striated vertical faces would permit. 



Crystals No. 3 and JVo. J^. — The relatively simple crystals 

 from the cavity walls connect directly with the two other 

 more highly modified crystals here described. 



Upon another* specimen and so in contact with the massive 

 luzonite as to be, in my opinion, developed from it, were a 

 number of little, bright, highly modified crystals which like 

 Nos. 1 and 2 are much lighter colored on the terminal faces 

 than on the side or prism faces. Crystal No. 3 was the best 

 of these found, and as shown in fig. 3 it proved to include all 

 the forms of JSTos. 1 and 2 as well as those of the later described 



crystal 4. Its size was -JXf Xl 1 

 respectively. 



in the directions a, b, 6 



