410 CHARACTERISTIC. CLASS II. 



2. .RHOMBOHEDRAL. Di-rhombohedral. P = 142 2<y, 

 80 25'. (P + n) m hemi-di-rhombohedral with pa- 

 rallel faces. 



Cleavage, Jl . P + oo. 

 H. = 5-0. 

 G. = 3-0 ... 3-3. 



Apatite. ii. 73. 



V. LIME-HALOJDE. Rhombohedral, prismatic. 



Cleavage, rhombohedral and paratomous, or 



prismatoidal. 

 H.= 3-0 ... 4-5. 

 G. = 2-5 ... 3-2. 



H. above 4-0 : G. = 2-8 and more. 



G. = 2-9 and more : H. == 3-5 and more. 



1. PRISMATIC. Prismatic. P = 112 39', 93 33 X , 123 34'. 



Cleavage, Pr _ 1 - 108 8'. (Pr + os) 3 = 63 44'. 



More distinct Pr + co. 

 H. = 3-5 ... 4-0. 

 G. = 2-6 ... 3-0. 



Arragonite. ii. 79. 



2. RHOMBOHEDRAL. Rhombohedral. R = 105 5'. 



Cleavage, R. 



H. = 3-0. 



G. = 2-5 ... 2-3. 



Rhomboidal Limestone. J. ii. 83. 



3. MACRO TYPO us. Rhombohedral. R = 106 15'. 



Cleavage, R. 

 H. = 3-5 ... 4-0. 

 G. = 2-8 ... 2-95. 



Dolomite. ii. 93. 



4. BRACHYTYPOUS. Rhombohedral. R = 107 22 ; . 



Cleavage, R. 



