42 PHYSIOGRAPHY. CLASS II. 



ty considerable quantities. It is found in many of the 

 veins near Freiberg, also at Marienberg, Annaberg, Schnee- 

 berg, and Johanngeorgenstadt in Saxony ; likewise at 

 Joachirasthal, Przibram, and other places in Bohemia. 

 The light red varieties are more generally met with in 

 the districts of the Saxon and Bohemian mines, nearer 

 the highest ridge of mountains, while the dark red occur 

 in greater proportion in the neighbourhood of Freiberg^ 

 and in other places of the lower districts. The dark red 

 silver is found in beautiful crystals at Andreasberg in the 

 Hartz. It is met with also at Schemnitz, Cremnitz, 

 Nagybanya, &c. in Hungary, in Alsace and Dauphiny in 

 France, at Kongsberg in Norway. Some other countries 

 produce but a small quantity of it, as, for instance, Corn- 

 wall ; but it is very abundant in Mexico and Peru. 



5. It is a valuable mineral for the extraction of silver. 

 It has been observed that the dark red yields a greater 

 quantity of silver than the light red variety. 



2. HEMI-PRISMATIC RUBY-BLENDE. 



One of the varieties commonly comprised among the 

 Dark Red Silver. 



Fundamental form. Scalene four- sided pyramid. 

 P = { J|p 5 i'}, 130 7', 77 16'. Inclination 



of the axis = 11 6', in the plane of the long 

 diagonal. Vol. I. Fig. 41. AP. 



a : b : c : d = 5-1 : 9-5 : 8-7 ; 1. 



Simple forms. P oo (b) ; = 128 59'; P-f- oo 



(/) = 86 <f; - g! ; - *" '+1 (t) = 47 



2 2 



26'; * Pr + g = 28 y. 



