MICROSCOPIC STRUCTURE OF MINERALS AND ROCKS. 
PLATE VIII. 

Ue 
Banded Obsidian. 
Fluxion structure in Pitchstone. 
Pegmatitic structure: intergrowth of Quartz and Felspar. 
Graphic Granite. 
Ophitic structure: lath-shaped crystals of Felspar enclosed in a large plate of Augite, which 
shows parallel cleavage. 
Diabase. 
[To face page 32. 
