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I Assembly 
It is on the immediate shore of the Hudson river, about 1 or 1 ^ miles 
below Caldwell's Landing, and above Tompkins' quarries. Prof. Cas- 
sels describes it as four or five rods wide, measured across the strata, which 
are rather thick layers and blocks than strata. It is stated that blocks 
of any reasonable size can be quarried here, free from cracks and flaws. 
It is of various shades of colour, from a deep spotted green to a beauti- 
ful bluish white. It is generally free from pyrites, but some blocks 
contain crystals of this mineral. The occurrence of this mineral would 
injure it for sawing and polishing, but Mr. C. reports that most of the 
quarry is free from this mineral, and that the verd -antique marble from 
this place takes a high polish. The quarry is on the shore, and vessels 
can come directly along side. The quarry belongs to Sampson Marks j 
Esq. 
Ores, 
Silver ore is said to have been found in several places in Rockland 
and Orange counties, and many wonderful stories are told about the 
mines once discovered, and which the discoverers have not been able to 
find again. I have seen no silver ore or any thing to justify the con- 
clusion that it exists there. 
The same remarks may be applied to lead ores. 
Copper ore is found in several localities in the trap and sandstone re- 
gion of Rockland county. The strongest indications of copper ore were 
seen about two miles from Sadenton, by the road side, between that 
place and Ramapo works. Thin seams and scales of green carbonate 
and the red oxide, were seen in abundance on and through the trap rock* 
These minerals were first discovered in the loose masses of the rock, and 
were traced up to their source in the ledges of trap rock in the hill on 
the east side of the road. Ko veins of copper ore were seen, but veins 
of silicious matter one-fourth of an inch thick traversed the greenstone 
trap, and the sides of these veins were frequently invested with a thin 
scale of the ore. It is not improbable that workable veins of this ore 
may be found in this vicinity. It is well known that copper ore has 
been found in some quantity associated with sandstone and trap rocks 
like those in New^-Jersey, Pennsylvania, Connecticut, Massachusetts, 
Nova Scotia, and on the shore of Lake Superior. Many mines have 
been opened in these various parts of the country, and considerable 
quantities of copper ore mined and sent to England to be smelted. 
Tlie arsenical ores of Orange county are discussed by Dr. Horton in 
the appendix to this report. 
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