The Collaborative International Dictionary of English v.0.48:

Granitic \Gra*nit"ic\, a. [Cf. F. granitique.]
   1. Like granite in composition, color, etc.; having the
      nature of granite; as, granitic texture.
      [1913 Webster]

   2. Consisting of granite; as, granitic mountains.
      [1913 Webster]

WordNet (r) 3.0 (2006):

granitic
    adj 1: showing unfeeling resistance to tender feelings; "his
           flinty gaze"; "the child's misery would move even the
           most obdurate heart" [syn: flinty, flint, granitic,
           obdurate, stony]
    2: hard as granite; "a granitic fist" [syn: granitic,
       granitelike, rocklike, stony]