170 



T. L. Walker — Temiskamite. 



Art. XII. — Temiskamite, a new nickel arsenide from 

 Ontario • by T. L. Walker. 



A few weeks ago the .Royal Ontario Museum of Mineralogy 

 received some specimens of niccolite from the Moose Horn 

 Mine, Elk Lake, Ontario. On examining some of the mate- 

 rial it was observed that much of the supposed niccolite was 

 much paler in color than normal niccolite. The examinations 

 thus initiated are detailed in the following paragraphs. 



Par agenesis. — This mineral occurs in calcite veins carrying 

 niccolite and smaller amounts of native bismuth and silver. 



Fig. 1. 



The new mineral appears to be one of the first to form. It is 

 bordered and fringed by niccolite and bismuth, while the cal- 

 cite appears to be later, as it fills in all the space between the 

 branching masses of the other minerals. 



Physical properties. — Color, silver-white with a touch of 

 red, tarnishing very quickly to madder gray, and after pro- 

 longed exposure to tints resembling those of bornite. Hard- 

 ness, 5*5 ; specific gravity, 7'901 ; fusibility, 2 ; luster, metal- 

 lic ; opaque; not magnetic ; streak, brownish black. 



Crystallography . — This mineral occurs in radiating fibrous 

 masses suggesting rammelsbergite in structure. No crystal- 

 lized material has yet been obtained. Traces of cleavage are 

 seen upon examining polished surfaces with the microscopey 



