176 



W. T. Schaller and F. L. JRansome — Bismite. 



An odd feature of these crystals is that the development of 

 the faces is so uneven, that no two faces of the same form are 

 present on the upper half of a crystal, though this is in part 

 due to the incompleteness of each crystal. 



From the foregoing observations it appears that the natural 

 bismite is not orthorhombic but belongs to one of the' uniaxial 



Fig. la. 



Fig. lb. 



systems, probably the hexagonal. Its presence in oxidized ore 

 appears to be uniformly indicative of bismuthinite in the origi- 

 nal sulphide ore. Some migration, however, has taken place 

 during oxidation and the scales of bismite do not always 

 occupy the exact positions of the parent needles of bismuth- 

 inite. 



U. S. Geological Survey, 

 Washington, D. C. 



