62 NEW YORK STATE MUSEUM 



FELDSPAR 



Although feldspar is the most common mineral among the Pre- 

 cambric rocks it is never likely to become commercially important 

 except in the pegmatite dikes or veins [see page 23]. Feldspar is 

 a valuable mineral used in the manufacture of porcelain and china- 

 v^are. During 1909 the only mine in operation was the one owned 

 by the Claspka Mining Co} of Trenton, N. J., and situated two 

 and one-half miles north-northeast of Batchellerville. Many acres 

 in this vicinity are rich in pegmatite veins although mining has 

 been carried on at but two points. The feldspar is very pure and 

 the deposit is no doubt a large one, but the mineral is generally so 

 intimately associated with quartz that a considerable expense is 

 involved in separating them. The feldspar is drawn to Northville, 

 from which point it is shipped to Trenton, N. J. 



MICA 



Mica is very commonly distributed through the Precambric 

 Grenville rocks in small flakes but only the large, clear (musco- 

 vite) mica is valuable. Much prospecting has been done for this 

 mineral but no mine has been successfully operated. A mine was 

 operated for a time two miles north-northeast of Northville and 

 just beyond the map limit. 



GRAPHITE 



Graphite, or so-called black lead, has been frequently noted in 

 the form of small flakes in the Grenville. So far as observed it 

 is most bundant in the rocks to the northeast of Batchellerville and, 

 about one and one-fourth miles east-northeast of that village, a 

 prospect cut some thirty or forty feet long has been run into the 

 Grenville, but real mining has never been attempted. The graphite 

 occurs irregularly in flattened masses, sometimes five or six inches 

 long and half an inch thick, between the layers of thin-bedded 

 Grenville. The Grenville rocks east of Batchellerville are much 

 like those farther eastward in Saratoga county where graphite is 

 being mined and it is quite possible that a workable deposit may 

 sometime be found. 



1 This property has recently been acquired by the Adirondack Spar Co. of 

 Glens Falls. 



