76 PHYSIOGRAPHY". 



p on m = 92 34' ; p on t = 88 C , * on h = 155 

 25', m on * = 112 30', TO" on A = 137 5', j> 

 on d = 150 25', g on m = 132 15', 7t on g 

 = 89 2(X. 



Cleavage distinct, parallel to ^? and t. Fracture 

 imperfect conchoidal. 



Lustre vitreous. Colour black, often greenish, 

 thin splinters are faintly translucent, and of a 

 green colour perpendicular to p, of a brown co- 

 lour parallel to it. In larger crystals it appears 

 opake. Hardness = 5*5 ... 6-0. 



It resembles certain dark coloured varieties of parato- 

 mous Augite-spar. According to Mr CHILDREN, it is 

 composed of silica, iron, manganese, and lime, with a trace 

 of titanium. It occurs at Arendal in Norway in small crys- 

 tals disposed on the surface of crystals of Albite. 



BARYTO-CALCITE. 

 HAL-BARYTE. 



Baryto-Calcite. BROOKE. Ann. of Phil. XLIV. p. 114. 

 Edin. Journ. of Science. Vol. I. p. 378. 



Hemi-prismatic. Combinations similar to Fig. 44. 

 and Fig. 188. Inclination of M on M 106 

 54', h on P (over a) = 106 8', P on M = 

 102 54', according to BROOKE ; b on b = 95 

 15', /* on the edge between b and b = 119, P 

 on the same edge = 135, c on c = 145 54', d 

 on d over h = 68. It is also found massive, in 

 granular compositions. 



Cleavage perfect, parallel to M, less easily obtained 



