?o 



NEW YORK STATE MUSEUM 



of the mineral represent the later or postfaulting period. Polished 

 sections of massive pyrite from a vein reveal microscopic inter- 

 growths of galena and pyrite; the former probably replacing the 

 latter. The percentage of the pyrite in the average rock is exceed- 

 ingly high. The findings of micro-analyses are as follows: Ore 

 from pit, 17 per cent; at head of pit, 7 per cent; rock from drainage 

 tunnel near shore of Rock pond, 40 per cent, by weight. In addi- 

 tion to the pyrite disseminated through the " arkosite " there are 

 true fissure veins, some of which are 4 to 5 inches wide. In fact, 

 the average run of the graphite ore contains more pyrite than 

 graphite, yet it was the latter mineral that alone was saved, the 

 sulphide being allowed to go into the waste. If more ore should 

 be found it would seem as if it would pay to save the pyrite for 

 sulphuric acid manufacture. 





Quantitative microscopic analyses of the Rock Pond 



" arkosite " 





No. 650 



Drainage 



tunnel 



No. 665 



South 

 side 

 of pit 



No. 681 

 Head 

 of pit 



No. 683 

 West 



corner 

 of pit 



No. 684 

 10 feet 

 south 

 of 683 





1 Grap 

 Biotil 



I Chlor 

 Orthc 

 Micrc 

 Ande 

 Quail 

 Pyrit 

 Muse 

 Serici 

 Carbc 

 Apati 

 Titan 

 Augit 

 Sillim 

 Galen 



TOTA 



^iite 



2.0 



trace 



5.0 



40.9 



.7 

 trace 

 10.3 

 40.0 



.6 

 trace 

 trace 



.3 

 none 

 none 



.2 



.3 

 100.0 



2.7 



trace 



7.4 



trace 



62.2 



2.9 



2.7 



17.5 



.3 



trace 



.3 



.1 



none 



.2 



none 



.3 



100.0 



1.4 



trace 



4.6 



trace 



68.4 



trace 



16.0 



7.6 



little 



trace 



little 



trace 



none 



1.8 



none 



.2 



100.0 



.4 

 1.4 



9.0 



trace 



70.0 



trace 



9.5 



3.0 



trace 



5.0 



1.5 



trace 



.2 



none 



none 



little 



100.0 





a 







Z 

 



ite 









H 







VI 







eu H 







§* 







<^~ 







H 



te . . . . 









< 



+0 









8 







si 







PU 







< 



L 













Z 



«» 



3z 



Q < 

 K 







.57 mm 



X 



.99 mm 



2.55 mm 

 .30 mm 



.31 mm 



X 



.50 mm 



1.02 mm 



.20 mm 





. 66 mm 



in 

 H 

 W 



w 



Maximum 



Minimum 



X 



.88 mm 



2 . 30 mm 



.30 mm 



a 



0. 



Z 



z 



1-1 H 



rz <~> 



C vi 



z z 



H 





.45 mm 

 . 60 mm 

 .30 mm 



.66 mm 

 .89 mm 

 . 34 mm 



.56 mm 

 .91 mm 

 . 35 mm 



.23 mm 

 .42 mm 

 . 18 mm 













u 



X 

 H 

 to 



c 

 w 



Minimum 







z z 



- 



'S. H 

 W U 



Average 



.077 mm 

 . 150 mm 

 . 049 mm 



.061 mm 

 . 082 mm 

 . 034 mm 



.031 mm 

 .061 mm 

 .023 mm 



.042 mm 

 .051 mm 

 . 020 mm 





(ft 

















