PHYSIOGRAPHY. 



Cinnabar. 



131 



Fig. 137. 



CINNABAR. Peritomous Melacone-Blende. 

 Primary form. Rhomboid. P on P' =72. 

 Secondary form. 



P on P' - 



P on 62 

 P on 63 

 P on e 

 a on bl 

 a on 62 

 a on 63 

 a on 64 

 e' on 61 

 e on 63 



Cleavage parallel to the primary form, highly perfect. 

 Fracture conchoidal. Surface of the crystals horizontally 

 streaked, sometimes very deeply. 



Lustre adamantine, inclining to metallic in dark colored 

 varieties. Color several shades of cochineal-red, the dar- 

 ker varieties inclining to lead-grey. Streak scarlet-red. 

 Semi-transparent . . . translucent on the edges. 



Sectile. Hardness=2'0 . . . 2-5. Sp. gr. =8-098, the 

 cleavage variety from Neurrnarktel. 



Compound Varieties. Twin-crystals, like Fig. 84, of 

 the compound varieties of Calcareous Spar. Rarely in 

 some indistinct imitative shapes. Massive : composition 

 granular, of various sizes of individuals, generally small and 

 often impalpable. In the last case, fracture becomes une- 

 ven, even, or flat conchoidal. Plates, superficial coatings. 

 There is sometimes a tendency to thin columnar composi- 

 tion, the mass being friable, and the color scarlet red. 



