106 NEW YORK STATE MUSEUM 



ment that might come from injection along definite planes, but is 

 quite uniformly intermixed as if the impregnation had taken place 

 with equal facility in all directions. 



In consequence of the method of origin the rock varies in ap- 

 pearance and character f roan place to place, and there would be some 

 difficulty in quarrying an even grade of product such as is required 

 in building stone. It is a good material, however, for purposes of 

 ordinary construction, in engineering works, foundations etc. 

 Though it has not been tested for crushing strength, there is little 

 doubt that it is fairly up to the average granite in that respect as 

 well as in other physical qualities that make for durability. 



Microscopically the rock appears quite fresh, except for incipient 

 alteration of the feldspar which is somewhat sericitized. There are 

 no sulphides ; very little of iron oxides, with magnetite as the single 

 representative ; and no chloritic ingredients. Along with the second- 

 ary quartz and feldspar appears a notable amount of apatite in 

 small prisms which is probably a pneumatolytic product incident to 

 the granite invasion. The biotite is largely concentrated about the 

 borders of the feldspar and quartz, as if it had been crowded out 

 from the spaces occupied by the latter during their crystallization. 



GRANITE NEAR GLOVERSVILLE, FULTON COUNTY 



Gneissic rocks suitable for most purposes for which massive 

 granite is used occur in the Adirondack Precambric area north and 

 west of Gloversville. The boundary between the gneisses which 

 form the Adirondack ridges and the Paleozoic sedimentaries at 

 their base crosses Fulton county diagonally from northeast to 

 southwest and is paralleled from Northville to Gloversville and 

 Johnstown by the railroad which, however, is generally from 2 to 

 3 miles distant from the foot of the ridge. 



The principal opening in the vicinity is the Edel quarry which is 

 situated 3^ miles northwest of Gloversville and is worked by E. T. 

 Edel of that place. It has supplied a large amount of architectural 

 and constructional stone for the prosperous communities along the 

 Mohawk river, having been operated more or less actively during the 

 last twenty years. At present, building and curb stone are the 

 principal products. 



The rock is dark gray and though distinctly laminated shows 

 little difference in appearance when cut parallel to or across the 

 bedding. The grain is fine and compact, with some coarser particles 

 of quartz and feldspar up to 3 or 4 mm in diameter scattered 

 through the mass. The feldspar is mainly microcline. White 



