PETROLOGY OF SOUTH CAROLINA GRANITES 739 
for general building purposes, the latter for monumental stock. ‘These 
do not differ essentially in mineralogy but bear no resemblance to 
each other in the hand specimens. 
The light-gray variety (Figs. 1 and 2) has no closely similar type, 
except mineralogically, in the South. Quartz, orthoclase (partly 
intergrown with albite as microperthite), microcline, oligoclase, 
biotite, apatite, zircon, and iron oxide, with the usual secondary 
minerals, make it up. Microperthite and micropegmatite are abun- 
Fic. 2.—Near view of a part of quarry face shown in Fig. 1. 
dant. Micropoikilitic structure (inclosures of irregular rounded 
quartz, feldspar, and quartz-feldspar intergrowths—micropegmatite) 
is rather characteristic of the larger feldspar individuals. 
_ The dark blue-gray variety of fine crystallization has many closely 
similar representatives, chief among which are the granites of the 
Excelsior Quarry in Lancaster County and near Newberry in New- 
berry County, S. C.; the Oglesby-Lexington dark blue-gray granite 
of Elbert and Oglethorpe counties, Ga.;' the Mooresville fine-grained 
1 Georgia Geological Survey, 1902, Bull. No. 9A, pp. 188-224; Amer. Geologist, 
Vol. XXVII (1901), pp. 202, 203. 
