74 NEW YORK STATE MUSEUM 



work at a new place, on lands owned by Raymond Moore, just 

 south of the King quarries. The granite is of light gray color, 

 medium to fine in grain, and belongs to the biotite variety. A 

 characteristic component is red garnet in small but plainly visible 

 grains or crystals disseminated through the body of the rock. Like 

 the Peekskill granite it belongs rather to the basic class allied to 

 the diorites and may be an offshoot of the Cortlandt intrusion. The 

 granite has been employed mainly in buildings in the towns along 

 the river. The guard house at West Point is a specimen structure. 



Yonkers gneiss. There are only a few quarries now active in 

 the Yonkers gneiss, though a considerable number are listed by 

 Eckel 1 as having been worked at the time of his report and the few 

 preceding years. The principal area of the gneiss is a belt that ex- 

 tends from near Van Cortlandt Park to Scarsdale in southern 

 Westchester county and that forms the ridge west of the Bronx 

 river. It also occurs in a considerable area between White Plains 

 and Kensico to the east of the Harlem railroad. There are dif- 

 ferent color varieties of the gneiss and Eckel states that the red 

 varieties are more open to decay than the blue, though for what 

 reason he does not explain. 



One of the large quarries in the Yonkers gneiss is that of Hackett 

 Brothers situated at the junction of Midland and Central avenues, 

 Dunwoodie. It is opened for a distance of 800 feet and has a 

 working face 40 feet high. The stone in the quarry has a bluish 

 appearance, but the hand specimens have a decided pink tinge from 

 the prevailing color of the feldspar. The grain is fine and the ar- 

 rangement somewhat foliated owing to the regular distribution of 

 the biotite in parallel bands. The jointing is not so close as to pre- 

 clude the extraction of large-sized blocks. Most of the output is 

 dimension stock. Good examples of the stone from the quarries 

 are found in many of the buildings in Yonkers, including St John's 

 and St Joseph's hospitals and several of the public schools. 



In the same vicinity is the quarry worked by John Russo. It pro- 

 duces building stone in small quantity for local sale. In character 

 and appearance the gneiss is similar to that obtained at the Hackett' 

 quarry, but the jointing is more closely spaced, permitting the ex- 

 traction of few large blocks. 



The quarry of Louis Perri lies a little east of the Hackett quarry. 



1 The Quarry Industry in Southeastern New York. Ann. Report State Geojc 

 gist 20, 1902. Also published separately. 



