218 



PHYSIOGRAPHY. 



CLASS II. 



P + oo. Dauphiny. 

 P + oo. Pr + oo. 



oo. 



Char, of Comb. Prismatic. 

 Combinations. 1. P oc. 



2. P oc. Pr + oo. 

 Dauphiny. 



3. P oo. f r -f n. P + oo. 



Fig. 13. Ratschinges, Tyrol. 



Cleavage. Very distinct in the direction of P oo ; 

 less easily obtained parallel to P -f- oo. Surface 

 P oo streaked parallel to the edges of combina- 

 tion with Pr, often divided in two faces, meeting 

 at a very obtuse angle of about 177 30'. P and 

 Pr are smooth, the rest of the faces streaked par- 

 allel to their edges of combination with P oo. 



Lustre vitreous, except upon P oo, which pos- 

 sesses pearly lustre, particularly if produced by 

 cleavage. Colour various shades of green, as 

 leek-green, mountain-green, apple-green, siskin- 

 green, &c. ; passing into white and grey. Streak 

 white. Semi-transparent ... translucent. 



Brittle. Hardness = 6-0 ... 7<0. Sp. Gr. = 2-926, 

 a greenish-white cleavable variety. 



Compound Varieties. Reniform, globular, sta- 

 lactitic shapes : surface generally drusy ; composi- 

 tion columnar, sometimes broad, imperfect, and 

 strongly coherent ; if the particles of composition 

 be distinct, the surface is often pretty smooth. 

 Massive: composition either columnar, as above, 

 or granular, and even sometimes impalpable. Some- 

 times compound varieties are again aggregated in a 

 second composition, the faces of composition being 

 rough and uneven, 



