The mining and quarry industry 1915 31 



is being done at a point near the second pit but lower down close 

 to a ravine which follows the slope of the ridge in a direction south 

 of east. Tunnels have been driven along the course of the beds 

 at points below the outcrop and the rock is mined underground so 

 as to obtain fresh material, better adapted for mill treatment. The 

 openings show fully 20 feet of rock fairly well charged with flake. 



The quartzite here contains less mica than in the more easterly 

 ledges and with the coarser size of the flake affords better material 

 for mill treatment. From the available exposures it would appear 

 that the graphite beds are found at two horizons, at least, within 

 the quartzite, although the latter has been broken up by intrusions 

 of the gabbro and by trap dikes so that the relations of the several 

 outcrops are not readily apparent. Thin beds of crystalline lime- 

 stone are intercalated in the quartzite, as can be seen in the bottom 

 of the ravine by the old mill where serpentinous limestone forms 

 the bed of the brook for some distance. 



The upward trend of prices which has characterized the market 

 for graphite during the past year or so has lent interest to the 

 Adirondack deposits, although no other developments were started 

 during 191 5. Occurrences of graphitic quartzite are common in 

 the eastern Adirondacks, and some may be found that appear to 

 be both extensive and fairly rich in graphite as the quartzite of this 

 region runs. Thorough tests are necessary, however, to show the 

 value of any particular occurrence for mining purposes. Many 

 failures have resulted in the business, due to lack of information 

 about the character of the deposits that were to be worked or of 

 the amenability of the material for extraction of the graphite. 



GYPSUM 



The gypsum industry was conducted on about the same scale as 

 was reported for the preceding two or three years, and without any 

 developments in the field that promise a change in the situation for 

 the current season. The output of crude rock was 516,002 short 

 tons, a few thousand tons more than in 19 14 but still somewhat 

 below the mark set in 1913 which was 532,884 short tons. 



The market for gypsum products, especially calcined plasters, 

 which had been rather depressed for some time owing to a condition 

 of oversupply and of competition among the producers, showed a 

 little improvement with an encouraging outlook for the immediate 

 future. The production has grown very rapidly, the plaster indus- 

 try being developed practically within the last decade, so that trade 

 conditions have not become fully adjusted. 



