FIRE TESTS OF NEW YORK BUILDING STONES 35 



dolomite in a cement of fine grained calcareous material and 

 limonite. Rounded quartz grains are scattered through the section, 

 thus giving the rock a silicious character. 



13 Limestone 



Palatine Bridge, Montgomery co. N.Y. 



MOHAWK STONE CO. 

 See plate 24 



This limestone has been used for building purposes, but at present 

 it is being quarried for railroad ballast. It is grayish blue in color, 

 quite compact and hard. For the most part it is quite fine in 

 texture, though it varies to a coarser grain. 



In the thin section were seen good calcite crystals, some small 

 grains of quartz and a few pieces of plagioclase changing to calcite, 

 all in a fine grained material which is probably calcite mixed with 

 more or less clay. A few magnetite grains were also seen in the 

 section. 



15 Limestone 



Amsterdam, Montgomery co. N.Y. 



D. C. HEWITT 

 See plate 2 5 



The stone from this locality is extremely variable. The good 

 stone, employed for building purposes, is dark gray, fine grained 

 and fairly even in texture. However, in it are coarser layers. 

 The poorer stone is rather black, loose, earthy and coarse. This 

 is used for road metal. 



The thin section shows the stone to be made up largely of calcite 

 crystals in a fine cloudy material which is probably a calcareous 

 material mixed with some clay. Some angular quartz grains and 

 a few plagioclase grains changing to calcite were also noted. The 

 texture is variable and there are some pore spaces. A few ore 

 grains are scattered through the mass. 



35 Marble 



Gouverneur, St Lawrence co. N.Y. 



ST LAWRENCE MARBLE CO. 

 See plate 26 



This is a fairly coarse grained stone of a bluish color, varying to 

 a lighter tint, used extensively for building and decorative pur- 



