220 NEW YORK STATE MUSEUM 



should not be too much discolored. In paint and wood-filler the 

 sajtne kind is employed in finely pulverized condition. 



A special investigation of the high-silica materials of the State 

 was carried out in 191 8 by R. J. Colony, and the results published 

 as bulletin no. 203,204 of the New York State Museum. 



Quartz sands. The sand deposits are described under a separate 

 title, and need not be given special attention here. It may be 

 remarked that the deposits are mainly of glacial origin and do not 

 rank very high in silica content, being mostly mixtures of quartz 

 with clay and various rock materials, so that they are seldom adapted 

 to the employments above described. The best materials are the 

 beach sands represented in the Oneida lake region and on the north 

 shores of Long Island. The former locality has supplied considerable 

 quantities of quartz sand for window-glass manufacture and fire and 

 core sands. 



Sandstones and Quartzites. Some of the bedded formations 

 contain sandstone members that are high in quartz content. These 

 include granular more or less open textured rocks, which belong to 

 the class of sandstones in the strict sense, and rocks which have 

 been cemented and filled with a secondary silica deposit forming a 

 solid mass of quartz, or a quartzite. 



One of the more widespread sandstones that often carries a high 

 quartz content is the Potsdam. This outcrops extensively on the 

 northern, eastern and southern borders of the Adirondacks. In 

 some places it is a hard, vitreous quartzite and in others it has the 

 open texture of sandstone. The beds range from a few inches to 

 two or three feet thick and are white, gray or pink in color. The 

 areas on the north side of the Adirondacks', particularly around 

 Moira and Bangor, Franklin county, seem to contain the highest 

 silica material, which has been used locally for glass manufacture 

 to some extent. On the east side at Port Henry and farther south 

 at Fort Ann there are exposures of fairly pure quartzite. On the 

 south side of the Adirondacks the Potsdam occurs in minor areas 

 of which one at Keck Center, Fulton county, yields a white granular 

 sandstone, with 96 to 99 per cent silica, that is used for ferro-silicon 

 manufacture. 



The Oriskany sandstone of the central part of the State has beds 

 of rather coarse, white, sugary quartz rock that is high in silica. 

 There are good exposures at Oriskany Falls, Oneida county, and 

 near Union Springs, Cayuga county. 



The Shawangunk grit is a coarse quartzite or conglomerate that 

 outcrops in Ulster, Orange and Sullivan counties. It is quarried 



