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NEW YORK STATE MUSEUM 



Pilfershire pits, 57, 68, 71. 



Plagioclase, found in anorthosites, 

 147 ; gabbros, 17, 62, 63 ; gneisses, 

 15, 45, 50, 7h 91, 92, 109, 161, 169; 

 granites, 127; magnetites, 152; peg- 

 matite, 114; schists, in; syenites, 



6S, 93- 



Plattsburg, furnace, 106. 



Podunk mine, 37-38. 



Porphyritic feldspar, 140. 



Porphyritic gneisses, 16. 



Porphyry, syenites, 19. 



Port Henry, furnace at, 7. 



Port Henry group, 57-88. 



Port Henry Iron Ore Co., 57, 86. 



Port Leyden mines, 147, 148, 168-69. 



Potash feldspars, Port Leyden ore 

 body, 148. 



Potsdam sandstone, 11, 19, 61, 108, 

 125. 



Potter, S. R., mentioned, 38, 39. 



Potter mine, 37-38; cross-section, 37. 



Precambric rocks, 11. 



Putnam, B. T., cited, 35, 37, 40, 50, 

 54, 61, 68, 71, 97, 116, 121, 127, 128, 

 138, 172. 



Putnam county, Tilly Foster mine, 

 72. 



Pyrite, 9 ; found in amphibolites, 14 ; 

 gneisses, 13, 27, 30, 32, 42, 45, 46, 

 89, 92, 131; granites, 30; lime- 

 stones, 13 ; magnetites, 25, 30, 38, 

 39, 40, 41, 90, 96, 114, 135, 139, 140, 

 145, 152, 162, 163, 164; quartzites, 

 14; schists, 37, 46, 91, 138. 



Pyroxene, found in anorthosites, 158; 

 gabbros, 17; gneisses, 15, 20, 71, 

 89, 131, 132, 143; limestones, 13, 

 46; magnetites, 24, 145, 152, 162, 

 163 ; schists, 15, 20. 



Pyrrhotite, 25, 96, 140. 



Quartz, analyses, 29 ; found in 

 gneisses, 13, 15, 27, 45, 46, 48, 89, 

 91, 92, 95, 103. 109, no, 115, 125, 

 132, 143, 144, 148, 169; granites, 18, 

 28, 37, 41, 46, 112, 126, 127; hema- 

 tite, 43; magnetites, 24, 32, 53, 55, 

 96, ioo, ior, 104, 113, 122, 135, 140, 



145, 152; pegmatite, 114; schists, 

 37, 46, 67; syenites, 18, 28, 64, 65, 



93- 

 Quartzite, 14-15, 40. 



Rand hill, 17, 109. 

 Red ore, 66, 80. 

 Redford, forge, 124. 

 Rock pond, quartzite, 14. 

 Rogers, J. & J. Co., 100, 102. 

 Rossi, cited, 146, 155, 156, 163; men- 

 tioned, 153. 

 Russia, forge, 106, 124. 

 Rutgers pit, 90, 103. 



St Lawrence county, 8 ; field work 

 in, 11; gneisses, 14; Grenville 

 series, 29 ; limestones and schists, 

 13; magnetites, 23, 25, 26; mag- 

 netite deposits, map, 129; mines, 

 128-45 ; quartzites, 14, 15 ; statistics 

 of ore production, 35. 



Salisbury, augite-syenite, 28; mine, 

 23, 142-45- 



Salisbury Steel & Iron Co., 144, 145. 



Sanford ores, see Lake Sanford ores. 



Sanford pit, Mineville group, 74. 



Santanoni mountain, anorthosite, 



157. 



Saranac, forge, 124; mine, 124, 126, 

 128. 



Saranac formation, 15, 27, 91, 109, 

 124. 



Saranac valley, mines in, 124-28; 

 statistics of ore production, 35. 



Saratoga county, 8. 



Scapolite, found in gneisses, 30, 132; 

 limestones, 13; pegmatite, 114; 

 schists, in. 



Schists, 11, 13, 15, 27, 28, 29, 30; 

 Arnold hill and Palmer hill, 91; 

 Crown Point mines, 40; foliation, 

 20; mines near Fort Ann, 37, 39; 

 Hammondville mines, 45, 46, 48, 

 50; Lake Sanford deposits, 157; 

 Lyon Mountain mines, in, 113, 

 122; Minerva mine, 89; Mineville- 

 Port Henry group, 62, 67; St 

 Lawrence county mines, 130, 138, 



