QUARRY MATERIALS OF NEW YORK 13I 



reddish grains, of irregular form, scattered through the ground- 

 mass ; the grains are not conspicuous as they are seldom over 5 mm 

 in diameter. 



The color of the diorite is dark gray, with a bluish tint. The 

 hammered surface, which is the usual finish, shows lighter and is 

 quite attractive. 



Faillace quarry 



The quarry operated by Faillace Brothers, of Mamaroneck, is on 

 the north side of the New Haven Railroad, and a little west of the 

 village. It is in the western of the two parallel belts. In the spring 

 of 1912, it was the only active quarry in the diorite. 



The quarry is situated on the side of a low ridge, which has 

 a northeasterly trend parallel to the general strike of the country 

 rocks. The face is about 200 feet long, falling to 30 feet at either 

 end. There is no sheet structure, but a system of discontinuous 

 joints, 6 or 8 feet apart, dips at a low angle to the south, parallel 

 to the surface. The principal jointing strikes and dips with the 

 foliation, that is, strikes northeast and dips northwest at an angle 

 of 65 °. There are also cross-fractures, but they maintain no 

 regularity. 



The rock is a dark, very biotitic variety of the diorite, but rather 

 more uniform in appearance than the average rock, and fairly 

 free of knots or streaks of any kind. It carries porphyritic feld- 

 spars, which are usually compressed into lenses, or completely 

 granulated, and which may reach an inch in maximum diameter. 

 The uncrushed individuals show simple twinning after the Carlsbad 

 law. The body of the rock has a fine grain, the quartz and feldspar 

 averaging about 2.5 mm across. Pink garnet is usually present in 

 small scattered granular aggregates that are noticeable but not 

 conspicuous. The rock has a fresh appearance which is confirmed 

 by negative tests for carbonates with dilute hydrochloric acid. 



The quarry is equipped with two derricks. There is a crusher 

 for using the waste. The principal product is rough and dressed 

 blocks for building purposes, foundations, walls etc. The dressed 

 material, for the most part, is finished with the patent-hammer. 

 The stone is well suited for practically all purposes that do not 

 require a light color or a fine finish. It is not susceptible, of course, 

 to polishing. The waste is sold for riprap or crushed at the 

 quarries. 



Campbell quarry 



The Campbell quarry, which is the only one in the vicinity men- 

 tioned by Eckel, has not been worked in the last four years. It is 



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