THE MINING AND QUARRY INDUSTRY igOJ 5 1 



merit are recrushed by rolls and reconcentrated on Hartz jigs. 

 The slimes are passed over Overstrom tables. The mill has a 

 nominal capacity of 500 tons crude ore a day. 



The ore bodies have much similarity of shape and geological 

 relations to the magnetites of the western Adirondacks. They 

 are of lenticular form with their axes of extension alined parallel 

 to the foliation of the wall rock, but often show a pitch across 

 the dip. They range up to 30 feet thick. They occur in over- 

 lapping series sometimes closely set and again separated by 

 varying thicknesses of the wall rock. The country is a dark 

 hornblende-biotite schist belonging to the sedimentary or Gren- 

 ville series of Adirondack formations. 



The pyrite occurs in coarse particles and aggregates which 

 only occasionally show crystal boundaries. The gangue consists 

 mainly of vein quartz. Zinc blende is a common accompani- 

 ment, and pyrrhotite is encountered at times in considerable 

 bodies. Though inclosed by sediments the deposits can scarcely 

 be construed as original beds of contemporaneous formation, 

 but their genesis probably has been parallel to that of the mag- 

 netites found in the Grenville which are always pyritic and not 

 rarely richly so. There are no well defined walls, for the 

 mineralization extends outward into the schist for some distance 

 beyond the limits of the pay ore. The pyrite seems to have 

 impregnated and replaced the schist to a great extent, at the 

 same time filling small fissures and seams along the bedding 

 planes. Its origin is traceable to iron-bearing solutions which 

 have circulated through the schist when it was probably at con- 

 siderable depth from the surface and perhaps in a less metamor- 

 phosed condition. 



The crude ore carries about 30 per cent sulfur. An analysis 

 of Stella ore showed the following percentages : 



Silica 32 



Iron 32 



Sulfur 32 



Copper -04 



Gold and silver traces 



The amount credited to silica probably includes the insoluble 

 constituents, such as feldspar, hornblende, biotite and other sili- 

 cates of the schist as well as quartz. The pyrite is froe from 



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