MINERAL RESOURCES OF THE STATE OF NEW YORK 295 



hanging side there is from 6 inches to 3 feet of soft foliated talc 

 which in appearance and texture shows strong contrast with the 

 fibrous talc of the main body. This foliated talc is sorted and 

 ground separately, producing a very soft white product which finds 

 special uses. 



The holdings of the Dominion Co. join the Balmat mine on the 

 northwest. Some development work has been done on the property, 

 but active production will be postponed until a mill is erected for 

 milling the product. 



Natural Bridge. Outside of the Edwards district the only con- 

 siderable production of talc in recent years has come from the 

 vicinity of Natural Bridge, Lewis county. The St Lawrence Talc 

 Co. has developed a new mine from which it has already produced 

 a considerable tonnage. Natural Bridge lies in an independent 

 belt of the Grenville limestone that parallels the Edwards belt a 

 ■few miles to the south. The first output was made in the year 

 igii. The talc from this locality differs from the characteristic 

 Edwards product in that it has a massive appearance, or at most 

 shows a granular habit never fibrous or coarsely foliated. The 

 color of the material mostly is grayish with some greenish inclusions 

 which apparently are in part serpentine and in part a chloritic 

 mineral. Under the microscope the material resolves itself into an 

 aggregate of finely divided scales which are bunched in more or 

 less distinct groups that assume at times a prismatic outline and 

 again are quite irregular. There is some indication of the former 

 presence of amphibole and pyroxene minerals but the alteration 

 to hydro-silicates has proceeded more completely than is usually 

 the case in the Edwards district. 



The product of this mine is ground locally in a mill erected by 

 the company for the purpose. The methods of milling are closely 

 similar to those used in the Edwards district. The output of ground 

 talc has been employed to some extent for paper; it is mainly sold, 

 however, for special uses. 



References 

 Brinsmade, Robert E. Talc in Northern New York. The Eng. & Min. Jotxr., 



Dec. 23, 1905 

 Diller, J. S. Talc and Soapstone. Mineral Resources of the United States, 



pt 2, 1912 

 Nevius, J. Nelson. Talc Industry of St Lawrence County, New York. N. Y. 



State Mus. Rep't 51, v. i, 1899 

 Smyth, C. H. jr., The Genesis of the Talc Deposits of St Lawrence County, 



N. Y. School of Mines Quarterly, v. 1896, p. 333-41 



