28 NEW YORK STATE MUSEUM 



magma crystallized in place, since it shows little resemblance in 

 form to a dike cutting the gneiss intrusively or to a vein occupying 

 a fissure. It constitutes a mass that is traceable for several hundred 

 feet along the strike and across the dip of the gneiss, and is as yet 

 only partially explored. The quarry is situated near the eastern 

 face of the ridge known as Breed's hill, i'^ miles south of Crown^ 

 Point and ^ mile west of the Delaware & Hudson Railroad. A large 

 mill has been erected close to the railroad, where the rock is con- 

 veyed by a cableway. The mill equipment is very complete and will 

 enable the company to supply feldspar in any of the forms in which 

 it is marketed. The pegmatite is an intergrowth of potash feldspar 

 and quartz with a little mica and tourmalin. The separation of the 

 minerals is effected entirely by mechanical means after crushing, 

 whereas in other quarries the removal of the quartz and iron-bearing 

 impurities is performed by hand cobbing. The feldspar belongs 

 to the variety known as microcline, which has the same chemical 

 composition as orthoclase, but differs in its crystallization. 



GARNET 



The abrasive garnet industry in the Adirondacks continued to 

 progress during 1907, as shown by the output which exceeded 

 all previous records, having been about 20 per cent larger than 

 that for the preceding year. There were no new discoveries, 

 and mining has been restricted to the usual localities. 



The North River Garnet Co., owning property at Thirteenth 

 lake, Warren co., is the largest operator in the region. The 

 company has an unlimited supply of garnet rock which is 

 obtained by open quarry work. The rock face now exposed 

 measures 142 feet in hight, while there is known to be an exten- 

 sive body below the level of the present workings. The material 

 is crushed and concentrated mechanically by a process specially 

 planned for the purpose by Mr F. C. Hooper. By the addition 

 of another unit to the mill, the productive capacity has been 

 raised to about 8000 or 9000 tons annually, which is considerably 

 in excess of the present market requirements of the country. 



The Gore mountain and Garnet peak properties near North 

 River are worked during the open season, the former by H. H. 

 Barton & Sons Co., and the latter bv the American Glue Co. 

 The garnet occurs in both places as large crystal masses in a 

 hornblende gneiss. It is separated by hand cobbing. 



On the slopes of Mt Bigelow in northern Essex co., about 



