FIRE TESTS OF NEW YORK BUILDING STONES 



31 



7 Norite 



Keeseville, Essex co. N. Y. 



PROPERTY OF C. B. WHITE 

 See plate 13 



The quarry at this locality is not at present in operation, but 

 formerly the stone was employed as a building stone. In the 

 quarry the stone is seen to vary considerably in texture and mineral 

 composition. The samples which were tested are greenish in color, 

 rather medium to fine grained and composed of green feldspar, 

 some biotite and some form of pyroxene. A few small garnets 

 were also noted in the hand specimen. 



No thin section was cut from this rock. 



9 Granite 



Grindstone island, Jefferson co. N. Y. 



PARRY BROS. 

 See plate 14 



This is a fine grained red granite which from this particular 

 quarry has been used only for paving blocks, although from other 

 quarries on the island it has been employed as a building and 

 monumental stone. The red color is due to an excess of pink 

 feldspar. Light and smoky quartz are easily distinguished as are 

 also little scales of biotite. 



In thin section the feldspars were seen to be chiefly microcline 

 with some orthoclase and an acid plagioclase. They are both 

 cloudy and clear; the orthoclase seems to have suffered the most 

 from alteration while the microcline remained fresh. Much quartz 

 js present. Both muscovite and biotite are represented, and 

 around some of the biotite scales chlorite and epidote occur as 

 alteration products. Some apatite crystals, magnetite, hematite 

 and other ore grains are present in small amounts. 



10 Granite 



Grindstone island, Jefferson co. N. Y. 



KELLY & PACKARD 

 See plate 15 



This is a coarse grained red granite which is used as a building 

 and monumental stone. The color is due to an excess of pink 

 feldspar, some of the crystals of which reach £ inch in size. 



