100 PHYSIOGRAPHY. CLASS n. 



5. PARATOMOUS* LIME-HALOIDE. 



Ilohwand, rohe Wand, Rosszahn, Wandstein of the Sti- 

 rian and Carinthian miners. 



Fundamental form. Rhombohedron. R = 106 

 12'. Vol. I. Fig. 7. R. G. 



a = V 2-0825. 



Simple forms. R QD (o) ; R 1 (g) = 135 

 54' ; R (P), Golrath, Stiria. 



Char, of Comb. Rhombohedral. 



Combinations. 1. R GO. R. Sim. Fig. 111. 

 Salzburg. 2. R 1. R. Gastein, Salzburg. 



Cleavage. R, perfect. Fracture uneven. Sur- 

 face ; R oo rough ; R 1 deeply striated 

 parallel to the edges of combination with R. 



Lustre vitreous, slightly inclining to pearly. Co- 

 lour, white, with various tints of grey, red, and 

 brown. Streak white. Translucent, often 

 very faintly. 



Brittle. Hardness=3-5...4-0. Sp. Gr. = 3-080, 

 a white cleavable variety. 



Compound Varieties. Twin-crystals. 1. Axis 

 of revolution perpendicular, face of composition 

 parallel to one of the faces of R -|- oo. Fig. 134 ; 

 this is also found in massive varieties (Golrath, Sti- 

 ria). 2. Axis of revolution perpendicular, face of 

 composition parallel to a face of R 1, generally 



* From vetpa about, and riftvu I cleave ; cleavable parallel 

 to the faces or the fundamental form. 



