388 



DESCRIPTIVE MINERALOGY. 



Erie County. This mineral is very abundant on the slate near Eighteen-mile creek, on 

 the shore of Lake Erie. There are also thousands of pyritized petrifactions near Buffalo. 

 Essex County. In almost all the mines of magnetic iron ore, iron pyrites occurs either in 



small grains or larger masses. It is also some- 



Fig. 449. 



Fig. 450. 



times observed in the white limestone. In the 

 vicinity of Port Henry, crystals are occasion- 

 ally found of the primary form (Fig. 448), and 

 of the octahedron with the solid angles replaced 

 by rectangular planes. Fig. 449 ; and also the 

 dodecahedron with pentagonal faces, dodeca- 

 edre of Haiiy, Fig. 450. P on d 152° 15' 52" ; 

 e on e 126° 52' 12" ; e on e' or e" 113° 34' 

 41" (Hauy). 

 Franklin County. About half a mile from the residence of James Duane, Esq., near the 

 road leading to Malone, there is an extensive bed of iron pyrites. On exposure to the air, 

 the entire rock is decomposed, and crumbles to the ground in the form of a green sulphate of 

 iron or copperas. There is a small stream in the vicinity, and it is thought that copperas 

 may be advantageously manufactured.* 



Jefferson County. In the town of Cham- 

 =• *^ • '^' "' pion, this mineral occurs radiated, plumose, 



and in crystals of a white and pale yellow 

 colour. The crystals are in the form of the 

 octahedron. Fig. 451 . d ond, over the base, 

 109° 28' 16". 



Crystals similar to Fig. 452, are occasion- 

 ally found with the preceding, on the banks 

 of Vrooman lake, near the village of Oxbow. 

 They are of a dark colour externally. P on 

 d 152° 15' 52". 

 Lewis County. About a mile and a half northeast of Natural bridge, iron pyrites occurs 

 abundantly in well defined cubes, in a kind of trappean rock. It occurs also massive, and is 

 of a bright bronze yellow colour. 



Near Martinsburgli, it is associated with calcareous spar, in the veins of galena which 

 there traverse the limestone. The crystallized variety sometimes assumes the form of the 

 cuneiform octahedron. The regular octahedron (Fig. 451) has also been observed at this 

 locality. 



* Si-e a communication of B. S. Roberts, m the Report of the Commissioners to survey the Ogdensburgh and Champlain rail- 

 road. Documents of the New-York Lcgistatun, 1841. 



