QUARRY MATERIALS OF NEW YORK 201 



towns along the Hudson river. There are several quarries, now 

 abandoned, of which those formerly worked by the Snowflake 

 Marble Co. have been the principal sources of architectural marble. 

 The beds of the best quality measure about ioo feet thick and stand 

 in vertical position; they are pure white, with very little foreign 

 matter. The grain is extremely coarse, so that on a fractured sur- 

 face the cleavage planes of the dolomite appear as large rhombic 

 mirrorlike faces. A specimen in the State Museum collections has 

 an average grain diameter of 8-10 mm. The texture is close and 

 well knit, the dry stone absorbing only .15 per cent of water, ac- 

 cording to Smock. The specific gravity is 2.87 and the weight 179 

 pounds to the cubic foot. Determinations of crushing strength by 

 General Gilmore gave a maximum of 24,825 and a minimum of 

 18,750 pounds to the square inch from six tests. The following 

 analyses illustrate the chemical composition of the marble: 



3 



S1O2 2.31 .10 .29 



A1 2 3 

 Fe 2 3 



MgCOs 36.80 45.04 43-H 



CaC0 3 59-84 54-12 54-8o 



I 



2 



2.31 



.10 



.40 



.0/ 



.25 



.11 



36.80 



45.04 



59.84 



54-12 



Total 99.60 99-44 



Analysis no. 1 is by H. Ries ; x no. 2 by C. F. Chandler ; 2 and 

 no. 3 by F. A. Wilber. 3 



The stone is too coarse for sawed or polished work. Its archi- 

 tectural quality may be observed in St Patrick's Cathedral (lower 

 walls) in New York and the Methodist Episcopal Church in 

 Ossining. 



TUCKAHOE, WESTCHESTER COUNTY 



A very active quarry industry was centered a few years ago at 

 Tuckahoe. There are several openings in a narrow belt of dolomitic 

 marble which extends in a north-northeast direction and is inclosed 

 by Fordham gneiss on the west and the Manhattan schist on the 

 east. The marble beds range from 40 or 50 feet to 100 feet or more 

 in width. Their outcrop is marked by a surface depression between 

 the ridges of harder rocks. 



1 N. Y. State Museum Bui. 44, 1901. p. 832. 



2 U. S. Geol. Surv. 20th Annual Rep't, pt VI, 1899, p. 423. 



3 N. Y. State Museum Bui. 10, 1890, table facing p. 358. 



