PHYSIOGRAPHY. 93 



Oxahevrite. 



1. Alone, before the blow-pipe, it does not melt, but becomes paler. 

 With borax, it melts with difficulty into a transparent -glass. 



2. It is found in Norway c 



OUVAROVITE. 



Primary form. Rhombic dodecahedron. 



Lustre vitreous. Color emerald-green. Transparent. 



Harder than Garnet. 



1. It does not fuse when heated before the blow-pipe, nor lose its color 

 or transparency. 



2. It is found imbedded in Chrome-Ore, in the environs of Bissersk in 

 Siberia. 



OXAHEVRITE. 



Primary form. Octahedron with a square base. 



Secondary form. The primary, having the angles at the base 

 truncated, so as to form when enlarged the faces of a square 

 prism. 



Cleavage perpendicular to the axis, but with much difficulty. 

 Surface even, but not brilliant. 



Color, light-grey, leek-green, olive-green, and reddish-brown. 



Hardness, rather below Apatite. Sp. gr. = 2-21. 



Compound Varieties. Massive : in thin seams and veins, 



1. Analysis. 

 By TURNER. 



Silica 50 76 



Lime 22-39 



Potash 4-18 



Peroxide of iron .... 3-39 



Alumina I'OO 



Fluoric acid a trace. 



Water 17-00 



2. It occurs in ligneous petrifactions, where the wood has been repla- 

 ced by Calcareous Spar, of a fine ochre yellow color, and more or less 

 crystallized. From Oxhaver in the north east of Iceland. 



OXIDE OF ARSENIC. (See White Arsenic.) 

 OZOKERITE. 



Massive. Composition impalpable. 

 Color, between green and brown. 



