granitite

plural granitites

1. countableuncountableAny of various types of granite containing a high percentage of biotite.

   For some time the presence of the diorite was unperceived, and it was considered a mere fine grained variation of the Cape Ann granitite.

   1890, Nathaniel Southgate Shaler, The Geology of Cape Ann, Massachusetts, page 606

   2 more examples

   In several places, notably on the road to Coffin's Beach, and in the vicinity of Bond's Hill, on the west side of Squam River, opposite the city of Gloucester, the diorite is in such a position as to indicate that it is included in the granitite.

   1889, J.W. Powell, Ninth Annual Report of the United States Geological Survey to the Secretary of the Interior, page 603

   Microscopically the muscovite granites exhibit an absence of biotite, and generally less magnetite and more quartz than the true granites. The granitites in the hand-specimen are somewhat darker in colour than the true granites,

   1906, James Mackintosh Bell, Colin Fraser, The Geology of the Hokitika Sheet, North Westland Quadrangle