THE MINING AND QUARRY INDUSTRY I913 51 



Jefferson county. Yellow mica, probably phlogopite, is found in 

 large plates near Henderson. Muscalonge lake, town of Theresa, 

 has afforded fine examples of crystallized phlogopite of brown 

 color, but in small individuals. 



St Lawrence county. Some fine examples of phlogopite crystals 

 in the State Museum are recorded as having been collected from 

 Somerville. Perfect six-sided prisms unmarked by fractures or 

 rulings and of brown color have a diameter of 12 inches. The 

 exact locality is not given, but it may be the same mentioned by 

 Beck as 2 miles north of Somerville, with limestone and serpentine 

 as the gangue materials. Judging from the samples, the occurrence 

 is of unusual interest. 



Small quantities of mica have been obtained from the town of 

 Fine, 2 miles north of Oswegatchie. Good sheets of reddish phlo- 

 gopite were shown to the writer as coming from that locality. The 

 last work on the deposit was in 1909. 



Muscovite is found in Edwards associated with the fibrous talc. 

 It is not, however, of commercial importance. 



St Lawrence county may be regarded as one of the more favor- 

 able sections for the occurrence of commercial grades of mica. 

 Granite intrusions of great size have taken place at different times 

 in the Precambric and on their borders may be found dikes and 

 lenses of pegmatite intersecting the older gneisses and schists. 

 Since the intrusion of the pegmatites there has been no great dis- 

 turbance from regional-metamorphic forces so that the mica is 

 little fractured in most occurrences, whereas the pegmatites in the 

 central Adirondacks often show the effects of severe compression. 

 The pegmatites carry both muscovite and biotite. The numerous 

 contacts of limestone and granite afford favorable conditions for 

 the occurrence of phlogopite, which, as stated, is found here and 

 there in specimens of commercial quality, though the real importance 

 of the deposits has never been adequately tested. The geological 

 relations in this part of the Adirondacks are very similar to those 

 in the mica-mining districts of Canada. 



MINERAL WATERS 

 New York has held for a long time a leading position among the 

 states in the utilization of mineral waters. The different springs, 

 of which over two hundred have been listed as productive at one 

 time or another, yield a great variety of waters in respect to the 

 character and amount of their dissolved solids. There are some 

 that contain relatively large amounts of mineral ingredients and 



