Source : Webster's Revised Unabridged Dictionary (1913)

Pyrophyllite \Py*roph"yl*lite\, n. [Pyro- + Gr. ? leaf.] (Min.)
   A mineral, usually of a white or greenish color and pearly
   luster, consisting chiefly of the hydrous silicate of
   alumina.

Source : WordNet®

pyrophyllite
     n : a white or greenish aluminum silicate mineral (resembles
         talc)