206 PHYSIOGRAPHY. 



Fergusonite. 



Secondary form. Fig. 196. 



s on s - 100 30' | z on *' 159 



Cleavage, traces parallel to s. Fracture perfectly con- 

 choidal. Surface rather uneven. 



Lustre imperfectly metallic, inclining to resinous. Color 

 dark brownish black ; in thin splinters, pale. Streak very 

 pale brown, like Rutile. Opake : in thin splinters, translu- 

 cent. 



Brittle. Hardness = 5-5 ... 6-0. Sp. gr. = 5*838. 



1. Before the blow-pipe, it loses its color and becomes pale greenish- 

 yellow, but alone, is infusible. It is entirely dissolved in salt of phospho- 

 rus, but some particles remain a long time unaltered. The pale green- 

 ish globule becomes opake by flaming, or on cooling, when very much 

 saturated. Before the whole portion has been dissolved, it assumes a 

 pale rose color in the reducing flame. 



2. Analysis. 

 By HARTWALL. 



Columbic acid . - - 47-75 



Yttria - - - 41-91 



Oxide of Cerium - - - 4-68 



Zirconia - - 3 02 



Oxide of tin 1-00 



Oxide of uranium 0-95 



Oxide of iron - - - 0-34 



