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granitite

American  
[gran-i-tahyt] / ˈgræn ɪˌtaɪt /

noun

  1. a granite rich in biotite.


granitite British  
/ ˈɡrænɪˌtaɪt /

noun

  1. any granite with a high content of biotite

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of granitite

First recorded in 1870–75; granite + -ite 1