A Geoscience Digital Image Library

TitleAlkalic granite from Quincy, Massachusetts
DescriptionThis is a dark gray granular intrusive igneous rock. It is an atypical granite and consists of K-feldspar, quartz, sodic amphiboles, and pyroxene (aegirine). The dark greenish color is not typical of granites; they are generally pink to white. This sample is about 10 cm across.
ChronostratigraphyCarboniferous (Probably Mississippian)
Geologic provinceQuincy Granite
LocationUSA ▹ Massachusetts ▹ Norfolk. Near Quincy.
PhotographerDexter Perkins. 2001-01-25.
CollectionWard’s Collection of Classic North American Rocks #4.
Key wordsgranite, intrusive, igneous, Massachusetts
Tech details656 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number22