THE ADIRONDACK GRAPHITE DEPOSITS 



49 



Geol., 5:137). Sample C is a composite sample analyzed by \V. II. 

 Hall in the laboratories of the Massachusetts Institute of 

 Technology. 



Quantitative microscopic analyses of the Dixon ores 



Quality 



No. 751 

 ' Bastard " 

 bed near 

 Summer 



pit 

 state road 



No. C 3-N 

 Main 



mine 



No. 850 

 Main 

 mine 



No. 851 

 Main 



No. 852 



Summer 

 pit 



Poor 



Average 



Above 

 normal 



Abo v? I A v :rafe 

 normal 



No. 8.S1 



Sun mer 



pit 



Ave a e 



££ 



Graphite 



Biotite 



Chlorite 



Oligoclase-andesme 



Microchne 



Orthoclase 



Quartz 



Pynte 



Apatite 



Titanite 



Zircon 



Tourmaline 



Garnet 



4.6 



.2 



22.0 



.4 



.2 



62.6 



1.4 



.6 



.3 



4.0 



Total. 



100.0 



5.2 

 2.4 



25^3 



1.4 



.5 



60.8 

 1.7 



A 

 .1 



9.8 



.3 



2.0 



16.0 



.3 



.3 



64.4 



5.9 



1.0 



L9 



3.8 

 .8 

 1 

 3 



1 

 5 



4 



100.0 



7 



8 



4 



4 



1 

 7 



2 



74 





5 





1 













100.0 



6.4 



. 7 



6 5 



14 .1 



.9 



.2 



67.0 



1.7 



1.0 



100.0 



w n 



X - 



Average . . . 

 Maximum . 

 Minimum. 



Average. . . 

 Maximum 

 Minimum . 



32 mm 

 50 mm 

 20 mm 



1 . 10 mm 



3.50 mm 



. 34 mm 



1 . 79 mm 



5 . 20 mm 



.30 mm 



1 .03 mm 



2 . 50 mm 



. 40 mm 



. 70 mm 

 1 . 40 mm 



.32 mm 



.014 mm 

 .025 mm 

 . 003 mm 



.045 mm 

 .074 mm 

 .020 mm 



.050 mm 

 , 089 mm 

 .020 mm 



.079 mm 

 . 147 mm 

 .020 mm 



.056 mm 

 . 095 mm 

 .020 mm 



.67 mm 

 1 . 42 mm 



. 35 mm 



. 043 mm 

 .070 mm 

 .012 mm 



The Dixon schist as shown at Graphite, both in the main mine and 

 in the Summer pit, is practically free from micaceous minerals. 1 



The ore has been rubbed or squeezed to some extent, resulting 

 in an easily disintegrated material. This is especially true in the 

 case of certain specimens of the Summer pit ore which falls to 

 pieces even by crumbling with the fingers. In one of the slides of 

 the ore from the main mine (no. C3-N) some of the graphite flakes 

 and pyrite grains were observed to be split apart, and in case of the 

 pyrite, penetrated by a secondary fibrous aggregate, probably of 

 sericitic mica. While the writer does not feel justified in going on 

 record that the sericite is replacing the graphite and pyrite, it cer- 

 tainly appears to be the case. The pyrite has been broken up into 



1 Newland, D. H., N. Y. State Mus. Bui. 161, p. 32. 



