28 NEW YORK STATE MUSEUM 



ments or the entrance of new companies into the field ; on the other 

 hand the enlarged operations were but a response to an improved 

 market situation after a period of severe depression. In 1907 the 

 production of the mines amounted to 5709 tons or over 400 tons 

 in excess of the total last year. In 1908 when the depression was 

 severest, it fell to 2480 tons, less than one-half the output of an 

 average year. 



The year was unmarked by any notable changes in the industry. 

 Most of the output as heretofore, came from the vicinity of North 

 River in the upper Hudson valley. The North River Garnet Co., 

 with mines on Thirteenth lake, Warren county, and H. H. Barton 

 & Son Co., owning mines on Gore mountain a few miles southeast 

 of the former locality, were the principal producers. The American 

 Glue Co. has worked a property near North River in previous 

 years, but did not make any output in 1910. Aside from the above 

 the only mines recently operated were those of the Warren County 

 Garnet Mills at Riparius, Warren county, and the American Garnet 

 Co. on Mt Bigelow, near Keeseville, Essex county. 



The market for abrasive garnet is limited and it has shown little 

 tendency to grow, at least of late years. The Adirondack region 

 furnishes almost the entire product that is mined in this country; 

 attempts have been made to develop the industry in other states 

 but do not appear to have been permanently successful. The present 

 position of the local mines has been secured solely through advan- 

 tages of economic production and marketing, as there is no 

 monopoly of the natural resources. It would appear, however, that 

 garnet of the requisite character for abrasive purposes occurs in 

 but few regions in sufficient abundance to be worked on a commer- 

 cial basis. ' M 



The value of abrasive garnet depends, of course, primarily upon 

 its hardness. This is a variable character and on the usual min- 

 eral scale garnet is classed as having hardness of from 6.5 to 7.5. 

 The limits as given are only approximate; as it is difficult and even 

 impossible to estimate hardness with precision. Chemical composi- 

 tion is undoubtedly a factor in determining the hardness ; of the 

 common kinds of garnet found in the iretamorphosed rocks, like 

 gneisses, schists and limestones, the iron-alumina variety (alman- 

 dite) is generally harder than the lime-alumina (grossularite) or 

 the lime-iron variety (andradite). Well-crystallized ,2^arnet is 

 tougher and probably also harder than granular or massive garnet 

 of similar composition. The property of toughness or tenacity is 

 very important in an abrasive which has to withstand considerable 



