74 NEW YORK STATE MUSEUM 



intergrowth of the two. Most of the feldspar has a grayish color 

 and belongs to the microcline variety. Alteration and softening 

 have taken place, with the formation of kaolin and sericite and 

 small amoimts of serpentine. The quarry pit is 125 feet long and 

 30 to 40 feet deep. 



Chestertown. A muscovite pegmatite, in which the mica is 

 abundant and of large size, is foxmd 3 miles south of Chestertown 

 on the north side of a high ridge i| miles east of the Warrensburg 

 road. It has been worked on a small scale for the mica, principally 

 in two pits of which the larger is south of and higher up the ridge 

 than the other and measures 50 feet long by 15 feet wide. The 

 full extent of the body is not revealed. 



Edinburg. Pottery spar has been obtained from a quarry on 

 the farm of Adelbert Gordon, 2 miles north of Batchellerville, town 

 of Edinburg, Saratoga county. The pegmatite outcrops at the base 

 of a ridge which forms the steep eastern slope of the Sacandaga 

 river valley, one-fourth of a mile east of the Day road. It has been 

 worked in two pits. The minerals occur in coarse crystals, the 

 feldspars attaining a length of fully 3 feet, but there is considerable 

 graphic intergrowth. Most of the feldspar is a gray microcline, 

 with subordinate amounts of a white variety which is probably 

 albite. Muscovite is abundant in certain parts; it forms books 

 and columnar crystals that measure a foot or more in diam.eter 

 and from i to 10 inches thick, usually showing inclusions of iron 

 oxides. Beryl is a common accessory constituent and attains 

 unusual dimensions. The feldspar is of excellent quality. The 

 main impediment to commercial operations is the long haulage; 

 the nearest railroad point is Northville, some 8 miles distant over 

 a rather difficult road. The Claspka Mining Co. opened the quarries 

 in 1906. 



Corinth. An extensive body of medium-grained pegmatite exists 

 about 3 miles southwest of Corinth station on the Adirondack branch 

 of the Delaware & Hudson Railroad. It has a width of 60 feet with 

 a vertical range of 130 feet in the outcrop; it can be traced for 2000 

 feet along the trend but not continuously. The feldspar and quartz 

 are too intimately intergrown for the mining of a high percentage 

 of high-grade pottery material, although the former is mostly a 

 potash variety. There is more or less biotite present. The occur- 

 rence is well adapted for making crushed pegmatite. 



•Mayfield. On the farm of Richard Tyrell, 3 miles west of Cran- 

 berry creek, town of Mayfield, Fulton county, is a deposit once 

 worked for pottery spar. The quarry has a face 50 to 60 feet wide 



