l66 NEW YORK STATE MUSEUM 



The pegmatite contains much graphic intergrowth of feldspar 

 and quartz, although the two minerals also occur separately to 

 a considerable extent. 



The quartz masses reach a diameter of 2 or 3 feet and the feld- 

 spar a similar size. Most of the feldspar has a grayish color and 

 belongs to the microcline variety. There is also a little pinkish 

 feldspar which may be orthoclase. Tourmaline and the iron-bearing 

 silicates generally have a very limited representation, though the 

 material is much stained by iron oxides, the result probably of 

 oxidation of sulphides. 



The pegmatite shows alteration in places, with the formation of 

 kaolin and sericite, and takes on a greenish coloration which seems 

 to be traceable to secondary serpentine. The presence of this 

 mineral is not connected apparently with any magnesium compound 

 of the pegmatite, but is referable to the alteration of the feldspar 

 and to the introduction of magnesium compounds from outside 

 sources. Apparently the pegmatite has been a channel for ground 

 water circulations. 



CHESTERTOWN, WARREN COUNTY 



Wilson Brown quarry 



The name of this quarry is given on the authority of residents of 

 Chestertown, who stated to the writer that the property was last 

 worked about fifteen years ago. The purpose of the operations 

 originally was the production of mica. The locality is 3 miles south 

 of Chestertown on the north side of a high ridge iy 2 miles east of 

 the Warrensburg road. Two workings may be seen, the principal 

 one being to the south and higher up on the ridge. This consists 

 of an open cut about 50 feet long and 15 feet wide on a dike or 

 elongated lens of pegmatite that strikes northeast. The limits of the 

 body are uncertain, except on the east side of the pit where the 

 country rock appears within a few feet of the wall. The more 

 northerly pit is probably a separate body, unless the pegmatite has 

 a much larger extent than seems to be indicated. It is a narrow 

 opening of undetermined depth. 



EDINBURG, SARATOGA COUNTY 



Gordon quarry 



In 19x6 the Claspka Mining Company of Trenton, N. J., opened 

 a quarry in the town of Edinburg, Saratoga county, which the com- 

 pany worked for two or three years for pottery spar. The locality 



