PHYSIOGRAPHY. 



Nepheline. 



79 



parts to the fluxes the color of the oxides of iron, affording at the same 

 time a strong smell of arsenic. 



2. Analysis. 

 By BERZELIUS. 



Arsenic acid 

 Peroxide of iron 

 Protoxide of iron 

 Water 



50-80 

 2300 

 1033 



15-87 



3. It is found in Brazil, near Villa-Rica, where it exists in cavities of 

 Limonite. 



4. It is doubtful whether this mineral can with propriety be distin- 

 guished from Cube-Ore. . 



NEPHELINE. Rhombohedral Feldspar. MOHS. 

 Primary form. Regular hexagonal prism. 

 Secondary forms. 



Fig. 326. Fig. 327. 



M 



Pon cl - 151 53' HAUY. 



Ponc2 - 135 40 PHILLIPS. 



Cleavage, parallel with M and P, both imperfect. - 

 Fracture conchoidal. Surface smooth and even. 

 Lustre vitreous to resincrus. Color white. Streak white. 

 Transparent . . . translucent. 



Brittle. Hardness =^6*0. Sp. gr. =2-56. 

 Compound Varieties. Massive : composition granular, 

 of various sizes of individuals. Faces of composition 



