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- 

 lings, 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 tovros of Northeast and Amenia, and among these are 

 »ome which excel in regard to texture and durabihty. 



All these, now comparatively neglected mines of wealth, would at once be opened up, if 

 »ome 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 

 Umestone, 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 Rensselaeriie* but which seems to me to be 

 nothing more than a mixture of serpentine and pyroxene. 



New- York 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, 

 s6me 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. 



