QUARRY MATERIALS OF NEW YORK 7I 



according to locality, but in general it may be said that red feldspar 

 constitutes about three- fourths of the whole, while quartz and 

 biotite are next in abundance. The feldspar consists of microcline, 

 microperthite, and oligoclase and shows some alteration. The 

 quartz has a bluish or opaque white color. Along with the biotite 

 there is some chlorite, evidently from alteration, and hornblende. 

 The minor ingredients include magnetite, titanite, pyrite, zircon and 

 apatite. The feldspar shows incipient decay, but is not materially 

 softened. 



The following chemical analysis is taken from Cushing's 

 " Geology of the Thousand Islands Region." It is based on a 

 sample from a quarry described as i mile southeast of Grindstone, 

 perhaps referring to the Gordon quarry. The analysis is by E. W. 

 Morley. 



SiO. 66.59 



AI2O3 14.54 



Fe203 2 . 42 



FeO 2.43 



MgO 1. 18 



CaO 2. IS 



NasO ;.. 3-o8 



K2O 5.62 



H2O 46 



TiO.o 81 



P2O5 40 



CI 03 



F 06 



S 08 



MnO ; 23 



BaO 17 



100.25 



Laboratory tests. Acording to Smock, a representative specimen 

 of the granite showed a specific gravity of 2.713, equivalent to a 

 weight of 169 pounds to the cubic foot. The absorption was 1.55 

 per cent of water. When subjected to a dilute solution of sulphuric 

 acid, the loss was .13 per cent. No apparent change was caused 

 by freezing and thawing, but exposure to a temperature of 1200°- 

 1400° F. caused vitrification, destruction of color and impaired the 

 strength. 



A more elaborate test of the fire-resisting qualities of the granite 

 was carried out by Mr W. E. McCourt. Two cubes tested to 550° 

 C. with slow cooling remained unchanged, but one developed a few 



