TAB. XCVII. 



FERRUM arseniatum. 

 Arseniate of Iron. 



Class 3. Metals. Order I. Homogeneous. 

 Gen. 6. Iron. Spec. 8. Arseniate. 



Diu. 1. Crystallized. Var. "J. Primitive. 



1 his arseniate of iron is one of the richest that has been 

 seen hitherto; and what adds much to the beauty of the 

 specimen is, that the lighter green cubes are accumulated in 

 groups, forming threads, lying on darker ones, all of which 

 are very pellucid. To add to the rarity of this specimen, 

 we find extremely fine fibres of an oxide of iron? partly 

 encircled by a band as it were of the arseniate, which re- 

 lieves the reddish brown dusty appearance of the oxide; 

 and this last, in return, relieves the glittering arseniate. 

 The fibres of the oxide are so fine that it requires a high 

 magnifier to see them ; we could not discover any other 

 than simple fibres. The top figure is of the natural size; 



