MINERAL RESOURCES OF THE STATE OF NEW YORK 2/3 



and general purposes. The principal exposures are on the northern 

 and northwestern sides of the Adirondacks. A continuous belt of 

 the Potsdam from 5 to 15 miles wide extends from Lake Champlain 

 across Clinton, Franklin and St Lawrence counties into Jefferson 

 county and to the St Lawrence river, as a border to the Precambrian 

 crystalline formations upon which the sandstone lies. Additional 

 though smaller outcrops occur on the east side of the Adirondacks 

 in Essex, Washington, Warren and Saratoga counties, and on the 

 north side of the Mohawk valley. They represent faulted and 

 eroded patches of once extensive belts of the sandstone that reached 

 well toward the interior of the highlands. 



The Potsdam, in places shows the character of quartzite, having 

 a body of quartz sand cemented by a secondary deposit of quartz, 

 and is then exceedingly hard, tough and durable. There is no 

 stone more resistant to weathering or better qualified to withstand 

 heavy strains. Samples have sustained a crushing strength of more 

 than 42,000 pounds to the square inch. The quartzite has a clear 

 white, pink to light red color, varying considerably in different 

 beds. Deep red colors which are occasionally to be seen imply the 

 presence of ferric oxide in considerable amount. As a rule the 

 beds are rather thin and their surfaces are often uneven owing to 

 ripple marks. The edges have a laminated appearance, especially 

 in the darker colored stones. Cross-bedding is not uncommon. 

 The Potsdam bears an excellent reputation as a building stone, 

 and the only difhculty with its employment for the purpose inheres 

 in its refractory character in regard to sawing and tool treatment. 

 For that reason it is used mostly in rock-face ashlar work. Many 

 important structures built of the pink and light red stone are to be 

 seen in the principal towns and cities of the State. 



Quarries in the Potsdam have been opened at Clayton, Chippewa 

 Bay, Hammond, Redwood, Potsdam, Malone, Bangor, Moira, 

 Burke and other places in the northern belt; also at Keeseville, 

 Port Henry, Whitehall and Fort Ann in the Champlain valley; 

 and near Keck Center in the Mohawk valley. The principal sources 

 of building stone have been the quarries near Potsdam and those 

 near Malone and Burke, Franklin county. The Potsdam Red 

 Sandstone Co. has supplied much ashlar from the quarries 3 miles 

 southeast of Potsdam. At Burke flagstone has been quarried, 

 largely for use in Montreal, 



The white Potsdam quartzite is a high-silica material that has 

 found application in years past for glass manufacture. The purer 

 beds carry 98 to 99 per cent or more SiOz, as exemplified by the 



