188 PHYSIOGRAPHY. 



CLASS II. 



5. Where it occurs in sufficient quantities, it is used as 

 a valuable mineral in the process of obtaining smalt 



GENUS III. IRON-MICA. 

 1. PRISMATIC IRON-MICA. 



Prismatic Blue Iron. JAM. Syst. Vol. II. p. 209. Man. 

 p. 115. Phosphate of Iron. Vivianite. PHILL. p. 238. 

 Blaue-Eisenerde. Krystallisirte Blaueisenerde. Vivi- 

 anit. WERN. Hoffm. H. B. III. 2. S. 302., IV. 2. 

 S. 144. Min. Syst. S. 9. 41. Eisenblau. HAUSM. III. 

 S. 1075. Phosphorsaures Eisen. LEONH. S. 357. 

 Fer phosphate'. HAUY. Tabl. comp. p. 99. Traite", 

 2de Ed. T. IV. p. 126. 



Fundamental form. Scalene four-sided pyramid. 

 P = :! *' , 134 31', 82 48'. Inclination 



of the axis = 10 53' in the plane of the long 

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



a : b : c ; d = 5-2 : 10-2 : 7-3 : 1. 



Simple forms. ?. = 119 4' ; (Pr -f oo) 3 111 

 2 



6'; (Pr-f <z>) 8 = 154 14'; ^ = 54 13'; 



?r + cc ; Pr -f- OD. 



p 

 Char, of Comb. Hemi-prismatic. _ = 71 34'. 



Inclination of P oo to Pr -f- OD = 100 53'. 

 Combinations. 1. . Pr + CD. Pr + oo. Sim. 



X 



Fig. 46. Bodenmais, Bavaria. 

 2. S* ?. (?r -f ex.) 5 . Pr + GD. Pr -f- OD. 



