250 PKOCEEDIXGS OF THE CANADIAN INSTITUTE. 



(b). The argentite is fi-equently associated with iron pyrites. 



(c). Galena is frequently closely associated with the argen- 

 tite, but I am informed that it does not carry silver. 



The Argentite is malleable, of lead grey and almost black color, 

 frequently iridescent and brittle, thus resembling stephanite. It 

 exhibits a radiating fibrous structure in botryoidal nuggets. Perfect 

 crystallization is very rare, though I have observed rhombic dodeca- 

 hedi'ons, cubes, and cubo-octohedrons and combinations of dodeca- 

 hedron cube and octohedron. 



Zinc Blende. 



1. Light yellow, called resin blende by the miners. 



2. Dark brown, liver-colored blende brown SPR. 



3. Dark w black (black jack) with which the argentite is very 

 commonl}' associated either as thin folia coating the blende, or 

 interpeneti'ating it in the cleavage planes. Some of this blende 

 assays as high as $300 per ton. 



a. As regards its position in the vein it usually lies next the 

 walls associated with galena in some of the veins, or about the 

 detached pieces of slate which are frequently present in the quartz 

 matrix. 



b. It is also occasionally scattered through the vein matter. 



In the linings of blast furnaces I have seen the same order as (a) 

 the zinc blende lying next to the firebrick and mixed with it, then 

 followed by galena coating it. 



Native silver when associated with the blende is usually mixed 

 with the light colored variety, and veiy rarely with the liver colored 

 variety. 



It is occasionally crystallized. I have observed tetrahedrons and 

 combinations of tetrahedron and rh. dodecahedron associated with 

 crystals of fluorspar. 



