118 
GEOLOGY OF THE FIRST DISTRICT. 
5. At a vein of magnetic oxide of iron and pyrites, within a few rods of the landing at Fort 
Montgomery. 
6. The “ Copperas mine,” so called,’ one mile northwest of Fort Montgomery. The sul¬ 
phate of iron, at this locality, is associated with white augite, limestone and serpentine. It 
was attempted to be worked by a company in New-York, but was abandoned. There seem 
two very good reasons why it should not be worked: 1st, because there seems to be an in¬ 
sufficient quantity of the sulphuret of iron for a permanent supply; and 2dly, the carbonate 
of lime would decompose the sulphate of iron, so that little or none of this salt would be 
obtained. 
7. An old mine hole on Mrs. Kingsley’s farm, near the summit of the mountain, one and a 
half miles southwest of West-Point, and three quarters of a mile west of the Hudson. The 
hornblende rock contains pyrites, and sulphate of iron effloresces on the rock.' According to 
tradition and common report, a lead mine has been found on this mountain. An old man is 
said to have supplied himself and neighbors, and the Indians had done the like before his 
time. Reports and traditions of similar import have been found common in many places in 
every county that I have explored, except Long, Staten and New-York islands. 
8. Sulphate of iron effloresces on the magnetic oxide of iron at the Clove mine, one mile 
south of Monroe. The ore makes hot short iron, in consequence of the pyrites contained in 
it. Copperas might perhaps be obtained from this ore with profit. 
In Ulster county, slight efflorescences of sulphate of iron were observed on the slate exca¬ 
vated a few years since, to find coal, at the base of the Shawangunk, two miles south of High 
falls. Some of the pyrites are very beautiful, with a crystalline and plumose arrangement, 
and often grouped in thin crystalline plates around a centre, like the petals of a flower. The 
slate is the black glazed slate of the Hudson-river group, with thin scales and glazing of car¬ 
bonaceous matter. 
The grit rock of the Shawangunk two miles south of Rochester, at one locality, was 
observed loaded with pyrites, which decompose and cause an efflorescence of sulphate of iron. 
The locality is one-third of a mile south of the Mulekill, and is known as the “ Silver mine 
but from which no silver has been, or probably will be obtained. A small excavation has 
been made in the rock. The pyrites do not seem sufficiently abundant to be important for 
the manufacture of copperas. 
In Albany county, on the east part of the Helderberg m'ountain, twelve miles from Albany, 
it effloresces in some quantity.* 
In Saratoga county. Dr. Steel has described the sulphate of iron as efflorescing on the 
transition rocks near Hadley’s falls.! 
Sulphate of iron is stated to occur near Calskill in Greene county, with calcspar, quartz 
and sulphate of lead,! 
* Eaton. Silliman’s Journal, Vol, 15, p. 243. 
t Steel’s Report on Survey of Saratoga county; Robinson’s Catalogue, p. 131. 
t PiEKCE. Silliman’s Journal, Vol, 5, p. 266. 
