468 J. M. Davison — Internal Structure of Cliftonite. 



In the case of the smaller crystal the grinding had reached or 

 passed the center of the internal octahedron before the first 

 measurement was made. In neither case was the grinding 

 pushed to disappearance of the internal form. 



This internal structure confirms the view that cliftonite is 

 not a pseudomorph after pyrite, for it would be impossible to 

 reproduce the internal structure of pyrite under the conditions 

 of the case. But it is not so clear that diamond has here been 

 changed to graphite rather than that graphite has crystallized 

 in a form differing from telluric graphite because of differing 

 conditions. 



Carbon crystallizing from molten iron under atmospheric 

 pressure takes the graphite condition with hexagonal form. 

 And, as Moissan has shown, it may, in some cases, under 

 greater pressure take the diamond condition with isometric 

 form. Why may it not under somewhat different circum- 

 stances take the graphite condition with isometric form having 

 a hardness greater than hexagonal graphite, as Brezina found 

 cliftonite to have ? 



The curving string of plates w T as likewise examined for 

 internal structure, but none was found. 



With the cliftonite crystals were a few transparent particles, 

 some of which withstood fusion with sodium carbonate and 

 four evaporations with hydrofluoric acid and presumably were 

 diamond fragments. 



Rochester, N. Y. 



