Fig. 3 Poughquag quartzite, Peekskill area; taken in polarized light 

 (nicols crossed), magnification 65 diameters. The quartz grains are fairly 

 free from included matter, and are firmly interlocked ; the large crystal 

 near the center of the field is a zircon of unusual size. No trace of the 

 original rounded grains remains because of the complete reorganization of 

 the rock. 



