NEW YOfeK STAtE MUSEUM 



types of the granite it occurs in rather large individuals having 

 one or more crystal boundaries and to some extent as an inter- 

 growth with the feldspar. Magnetite represents the principal iron 

 ore, and no pyrite could be found in the sections. Apatite and 

 zircon are among the accessory minerals. 



The sample taken from the surface reveals little weathering or 

 decomposition that is detrimental to the appearance and strength 

 of the stone. There is no sap or iron stain in any amount and 

 the effects of exposure to the elements are mainly noticeable in the 

 clouded appearance of the feldspars and the conversion of a part 

 of the ferromagnesian silicates into chlorite. 



In regard to texture the granite shows considerable variation 

 from place to place, though within narrower limits it maintains a 

 degree of uniformity that makes possible the production of an 

 even grade of material. The coarse phase is thoroughly massive, 

 sometimes faintly gneissoid, and has a semiporphyritic appearance, 

 with feldspars measuring from .5 to i inch diameter in a fine ground- 

 mass of feldspar, quartz, hornblende and mica. Another variety has 

 an even granular texture, ranging from medium -to coarse. Still 

 other types show quite marked gneissoid and cataclastic textures 

 as the result of pressure metamorphism, more apparent on the edges 

 of the area. 



Chemical analyses. The chemical composition of the granite 

 is fairly exhibited in the following analyses made from the samples 

 taken at different places along the line of the Carthage & Adirond'ack 

 Railroad. They reveal the essential ingredients in their respective 

 proportions, but do not give the less important ones like manganese, 

 zirconium and phosphorus which have little or no influence upon the 

 general character of the granite. The summary consequently falls 

 somewhat short in each case of the full amount. The analyses were 

 made by R. W. Jones, of the Museum staff 



SiOz 



AI2O3 



Fe^Os 



FeO 



MgO 



CaO 



Na^O 



K3O 



H2O+ 



H.0- 



99.66 98.66 98.14 



No. I 



No. 2 



No. 3 



75.01 



72.69 



70.03 



12.88 



14. II 



13.12 



.02 



.26 



2.04 



2.01 



2.89 



3.66 



.41 



.28 



.74 



1. 10 



.64 



1. 61 



Z.67 



2.37 



2.21 



4.16 



5.16 



4.14 



.32 



.24 



• 53 



.08 



.02 



.06 



