Source : Webster's Revised Unabridged Dictionary (1913)

Crystallography \Crys`tal*log"ra*phy\ (kr?s`tal-l?g"r?-f?), n.
   [Gr. kry`stallos crystal + -graphy: cf. F. cristallographie.
   See {Crystal}.]
   1. The doctrine or science of crystallization, teaching the
      system of forms among crystals, their structure, and their
      methods of formation.

   2. A discourse or treatise on crystallization.

Source : WordNet®

crystallography
     n : the branch of science that studies the formation and
         structure of crystals