GRANITE. 
525 
(A.) PRIMARY ROCKS OF NEW-YORK, WESTCHESTER, DUTCHESS AND 
PUTNAM COUNTIES. 
The rocks of these counties are numerous, many of them are applied to useful purposes, 
and they are every where abundant, and are seen cropping out from the surface of almost 
every hill and ravine. The principal rocks are, 
1. Granite. 
2. Sienite. 
3. Gneiss. 
4. Mica slate. 
5. Augite rock. 
6 . Greenstone and hornblende rocks. 
7. Q,uartz rock. 
8 . Talcose slate. 
9. Limestone. 
10 . Serpentine. 
11. Steatite. 
The five latter rocks have already been described as Metamorphic rocks. The others 
remain to be described. 
T. Granite. 
This rock occurs abundantly in New-York, Westchester, Dutchess and Putnam counties. 
It presents all varieties of texture, from a very coarse grained rock, to one almost perfectly 
compact. In color it varies as much as in texture. It is white, red, grey, yellowish and 
bluish grey, according to the color of the minerals forming it. The color of the felspar 
usually determines that of the mass. It occurs in beds, in veins, in interstratified masses, 
and in knots, knobs, and protruding m-asses, in which no connection with veins or beds have 
been traced. The more common mode of its occurrence is in beds ten to one hundred feet 
thick, interstratified with gneiss. Some of the granite is too coarse for use as a building 
material. Some is too compact and hard, being, in fact, eurite ; others are well adapted for 
building. Different localities show a great variety in strength, and in the ease or diflSculty of 
dressing, as well as in the ease of quarrying and the magnitude of the blocks that can be pro¬ 
cured. In the Geological Report of 1838, it was mentioned that many places would undoubt¬ 
edly be found in the Highlands, where fine quarries would be opened, and furnish “ building 
materials of the best quality, and which would endure the changes of our variable climate 
for ages without decay or disintegration.” The investigations subsequent to that time have 
verified the prediction that such localities might be found. The materials are of the best 
quality, easily quarried in large blocks, suitable for columns, cornices, etc., easily dressed, 
enduring as time, as the naked crags themselves will testify; and several of the localities, 
