112 T. L. Walker — Notes on Sperrylite. 



in connection with the detection of sperrylite in fragments of 

 chalcopyrite, while a careful search did not reveal it in the 

 pyrrhotite fragments, renders it very probable that the plati- 

 num found in the Sudbury district, in the copper-nickel mines, 

 in general occurs as sperrylite and that this mineral occurs 

 generally if not exclusively in chalcopyrite. It should be 

 mentioned here, however, that according to some analyses,* 

 polydymite, which occurs very sparingly in some of the Sud- 

 bury mines, contains from 0*006 per cent to 0*024 per cent 

 platinum. Sperrylite dissolves slowly in strong hot hydro- 

 chloric acid, more readily in aqua regia, while in nitric, sul- 

 phuric and hydrofluoric acids it is practically insoluble. 



An analysis of Manhee matte from Murray mines gave the 

 following results : 



Nickel (with trace cobalt) . _ 4S"osj& 



Copper 25*92 



Iron . . 2*94 



Sulphur 22*50 



Gold -000075 



Silver _ -001775 



Platinum. -000430 



Iridium _ -000056 



Osmium -000057 



Rhodium small quantity 



Palladium small quantity 



Total. 100-182393^ 



In this as in similar analyses made by others the presence of 

 iridium and osmium is noted. In Professor Wells's analysesf 

 of sperrylite these metals are not detected, though he was at 

 special pains in searching for iridium. Baron H. B. von 

 Foullon^: concludes, from the presence of these metals in the 

 Sudbury ores, that there is another mineral present which con- 

 tains the iridium. This is possible, but more probably in some 

 cases part of the platinum in sperrylite is replaced by the 

 elements iridium and osmium. This would not appear to be 

 the case, however, in the Vermillion mine sperrylite as shown 

 by Professor Wells's analyses. 



The above observations were carried on in the laboratories of 

 the School of Mines at Kingston, Ontario, and at the Mineral 

 Institute at Leipzig. For advice and assistance I am especially 

 indebted to Dr. W. L. Goodwin and Professor Nicol of 

 Kingston and also to Herrn Geheimrath Professor Zirkel of 

 Leipzig. 



Leipzig. Saxony, November, 1895. 



•Bull. U. S. Geol. Survey, No. 64, p. 21. 



\ This Journal, 1889. - 



% Jahrb. d k. k. geol. Reichsanstalt, 1892, p. 301. 



