68 
ECONOMICAL MINERALOGY. 
Dutchess County. Beds of marble similar to those found on the borders of this State, in 
Massachusetts, exist in various parts of this county; as in the towns of Amenia, Dover, Paw- 
lmgs, Beekman and Fishkill. The Dover quarries have been extensively wrought; and the 
marble which they yield, although dolomite, is pure white, fine grained, and takes a medium 
polish. Sometimes it is very friable, especially when first quarried. A specimen of this kind 
gave the following results upon analysis, viz : 
Carbonate of lime,... 60.50 
Carbonate of magnesia,. 39.50 
Clouded marble also occurs in the towns of Northeast and Amenia, and among these are 
some which excel in regard to texture and durability. 
All these, now comparatively neglected mines of wealth, would at once be opened up, if 
some easy and direct mode of communication could be established between them and the 
Hudson river. 
Essex County. In the immediate vicinity of Port Henry on Lake Champlain, and else¬ 
where in this county, beds of white limestone occur, which would be suitable for marbles. 
The verd antique variety, consisting of grains of green serpentine diffused through the white 
limestone, is also found near Port Henry. It seems to be sufficiently free from cracks and 
flaws, and would no doubt bear a good polish. The same mineral also occurs abundantly at 
Moriah in this county. 
According to my analysis, the limestone from Port Henry contains a portion of magnesia. 
In Franklin County, beds of white primitive marble are abundant. 
Jefferson County also contains deposits of a similar kind, but they have not yet been 
sufficiently explored to determine their real value. 
Lewis County. Extensive beds of a dark and compact serpentine occur in the immediate 
vicinity of Natural Bridge. The specimens obtained from this locality are susceptible of a 
high polish; and it is probable that large slabs may be obtained free from checks or flaws, 
which would answer the purposes of an ornamental marble. Some of the beds belong to that 
peculiar variety which Dr. Emmons has named Rensselaerite* but which seems to me to be 
nothing more than a mixture of serpentine and pyroxene. 
New-Yoric County. The quarries at Kingsbridge have furnished a considerable amount 
of marble. It is granular, and belongs to the dolomitic variety. By exposure to the weather, 
some of the specimens fall to pieces, and form a kind of calcareous sand. It is now, I believe, 
chiefly used for burning into lime. 
Niagara County. The rock at the village of Lockport is sufficiently compact to be po¬ 
lished, and it has been used for some ornamental purposes. It contains fragments of organic 
New - York Geological Reports , 1837. 
