Fig. 8 Photomicrograph of conglomeratic quartzite (Shawangunk) from 

 quarry near Accord; taken with nicols crossed, magnification 65 diameters. 

 Crushing, granulation, and silicification have destroyed grain outlines; 

 especially well shown by the grain in the center of the field. Mill wheels 

 (buhr stones) are made from this rock. Average grain diameter about 

 0.45 mm, disregarding the very large pebbles which are two or three centi- 

 meters in diameter, and occasionally larger. 



