U. S. GEOLOGICAL SURVEY 
BULLETIN NO. 182 PL. IX 
i ,- - c- 
Cr 
B. Sunnyside lode. 
NORMAL VEIN-QUARTZ STRUCTURE. 
Magnified 1 7 diameters ; nicols crossed ; black areas, chalcopyrite ; Q, quartz: C, chlorite; G, galena: 
S, sphalerite. 
