426 CHARACTERISTIC. CLASS II. 



VI. PETALINE-SPAR. Prismatic. 



H. = 6-0 ... 6-5. 

 G. = 2-4 ... 2-5. 



1. PRISMATIC. Prismatic. 



Cleavage, a prism of 95 (nearly). More distinct, 

 Pr + 05. 



Petalite. ii. 248. 



VII. FELD-SPAR. Rhombohedral, pyramidal, 



prismatic. 

 H, = 5-0 ... 6-0. 

 G. = 2-5 ... 2-8. 



H. = 5-5 and less : form pyramidal, 

 cleavage not axotomous. 



1. RHOMBOHEDRAL. Di-rhombohedral. P = 139 19*, 



88 6'. 



Cleavage, R . oo. R + oo. 

 H. = 6-0. 

 G. = 2-5 ... 2-6. 



Nepheline. ii. 250. 







2. PRISMATIC. Hemi-prismatic, = 126 12'. Inclina- 



tion = 0. 



Pr 



Cleavage, _ = 64 34', perfect. Pr + os perfect, 



but often interrupted. (Pr + co) 3 = 118 52', im- 

 perfect. 



H. = 6-0. 



G. = 2-5 ... 2-6. 



Prismatic Felspar. J. ii. 251. 



3. PX-RAMIDAL. Pvramidal. P = 136 7 ; , 63 48'. 



Cleavage, P + oo. [P + oo]. Traces of P oo. 

 H. = 5-0 ... 5-5. 

 G. = 2-5 ... 2-8. 



