THE LEOPARDITE OF NORTH CAROLINA 219 



MICROSCOPICAL DESCRIPTION. 



In thin sections the rock consists of a holocrystalline groundmass and 

 scattered small porphyritic crystals. Flow- structure is not exhibited 

 in the groundmass, and the phenocrysts indicate no orientation with 

 respect to each other. The groundmass is micro-granitic in structure, 

 though some sections show much of the micro-granophyric structure, 

 with an irregular radial, spherulitic, structure developed in greater or 



Fig. 2. — View showing approximately parallel black streaks and pencils on rock 

 surface broken parallel to the direction of the pencils. Photographed from hand 

 specimen. (One-half natural size.) 



less proportion in all of the sections studied. When they form com- 

 plete spheres, which is rarely the case, they usually exhibit somewhat 

 irregular ragged peripheries, and further show usually between cross 

 nicols a very indefinite black cross. The form of the grains in the 

 typical micro-granitic areas of the groundmass is sharp and allotrio- 

 morphic to partially idiomorphic. The principal groundmass minerals 

 are feldspar and quartz, with much light-colored mica, and an occa- 

 sional inclusion of prismatic apatite and zircon. Irregular minute 

 grains of iron oxide are scattered through the sections, and stained 



