Geographical Distribution. 11 



are rare and nearly all of the granite and syenite can be cleft in one way 

 more readily than in another, that is, the stone is said to have a grain to 

 it. The durability also is affected by the nature of the minerals. Thus, 

 pyrite may occur, and by its decomposition cause deca}^. Or there 

 may be a more easily decomposing feldspar which by its decay will 

 make the mass to crumble. Or by an excess of mica the stone may 

 be particularly liable to split or scale off, when exposed to the action 

 of freezing weather. Owing to these almost infinite variations in 

 composition and, consequently, in structure and texture no general 

 description will cover all the forms and varieties. But it may be 

 said here that there is comparatively little of the massive and 

 unstratified (granites and syenites) varieties. The greater part of the 

 crystalline rocks, particularly in the south-eastern part of the State, 

 occurs in beds as schistose gneisses and granitoid and syenite gneisses. 

 The stratified condition is predominant in all the border of the 

 Adirondack region also. 



The term granite is applied to rocks found in great masses and 

 outcrops over large areas in the central and eastern portions of the 

 Adirondack region, which are not strictly such. Instead of potash 

 feldspar they have a lime feldspar (labradorite) and with it quartz 

 and hornblende. 



Granites, syenites, gneisses and mica schist occur in the counties 

 of Rockland, Orange, Westchester, Putnam and Dutchess and on 

 New York island. For constructive material quarries have been 

 opened at many points, generally near railway lines or on the Hudson 

 river. The Breakneck and Storm King mountain granite quarries 

 were opened many years ago, and described in Mather's report on 

 the First District of the State. Gneiss has been quarried at Spuy- 

 ten Duyvill ; near Hastings ; at Valentine's, east of Yonkers ; at Ford- 

 ham ; near Hartsdale ; at Kensico ; at Tarrytown, in Westchester 

 county ; at Ganung's quarry, west of Croton Falls ; at Cold Spring 

 and near Anthony's Nose, north-west of Peekskill in Putnam county; 

 at Ramapo, in Rockland county; and in Orange county, at West 

 Point, Cozzens and Fort Montgomery. There are many other locali- 

 ties where stone has been quarried for local use, which are not worked 

 for export, or steadily as quarries. The outcrops of gneissic rocks 

 are so numerous and so extensive that the supply is inexhaustible, 

 and the number of quarries which can be opened is equalled only by 

 the area of territory covered by these outcrops. Particularly ad- 

 vantageous locations are to be seen along the Hudson river from 



