312 T. L. Walker — Nickeliferous Pyrite from Ontario. 



Art. XXXII. — Notes on Nickeliferous Pyrite from Murray 

 Mine, Sudbury, Out. ; by T. L. Walker. 



The principal nickel ore of the Sudbury district is nickelif- 

 erous pyrrhotite. In smaller quantities, nickel occurs in seve- 

 ral other forms such as niccolite, gersdorffite, pentlandite, 

 polydymite, and nickeliferous pyrite ; these minerals are how- 

 ever often in such quantities as to be of great economic im- 

 portance. It is intended in the present article to give a few 

 notes on the occurrence of nickeliferous pyrite. 



At the Murray mine on the main line of the Canadian 

 Pacific Railway about four miles northwest of Sudbury is 

 found a nickel-iron sulphide containing from four to six per 

 cent of nickel. The writer first had his attention drawn to 

 this mineral in 1891 when assayer at the above mine. Dr. 

 W. L. Goodwin of the Kingston School of Mining published 

 some notes on this mineral in the " Canadian Record of Sci- 

 ence " for April, 1893 — the specimens then at hand however 

 were massive and somewhat decomposed. The ore occurs in 

 a rock, which on microscopic examination proves to be diorite, 

 which is coarsely crystalline and weathers easily, so that for a 

 few feet below the surface the rock is decomposed and crum- 

 bles to pieces when exposed to the air, exposing the kernel- 

 like masses of pyrite. Marcasite (containing no nickel or 

 cobalt), magnetite, galena, chalcopyrite and nickeliferous pyr- 

 rhotite are the associated minerals. At first only massive 

 specimens were found, but during the summer of 1893 the mine 

 was again visited and several specimens were obtained showing 

 druses of small bright cubic crystals. These were examined 

 and shown to contain nickel, but as they were very small no 

 quantitative analysis was made of them. The interfacial 

 angles of the crystals were measured under the microscope 

 and found to range from 90° to 90° 40', which, when it is re- 

 membered that the largest crystals measured only •3 mm , is a 

 very close approximation to the cube. The characteristic 

 striae of pyrite could not be detected. Some of the larger 

 crystals were pressed into a pine splinter and bright surfaces of 

 calcite, fluorite and apatite were in turn scratched. Orthoclase 

 was too hard to be scratched by them — the hardness of the 

 crystals is thus between 5 and 6, which is quite close to that for 

 ordinary pyrite. The mineral strikes fire with the hammer. 

 Specific gravity, color, lustre, and magnetic properties are the 

 same as in ordinary pyrite. The mineral is insoluble in hydro- 

 chloric acidbut dissolves readily in nitric acid. 



An analysis was made of some of the massive pieces, show- 

 ing no signs of decomposition, with the following result : 



