The Collaborative International Dictionary of English v.0.48:

Albite \Al"bite\, n. [L. albus white.] (Min.)
   A mineral of the feldspar family, triclinic in
   crystallization, and in composition a silicate of alumina and
   soda. It is a common constituent of granite and of various
   igneous rocks. See Feldspar.
   [1913 Webster]

WordNet (r) 3.0 (2006):

albite
    n 1: a widely distributed feldspar that forms rocks [syn:
         albite, white feldspar]