The Collaborative International Dictionary of English v.0.48:
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. [1913 Webster]WordNet (r) 3.0 (2006):
pyrophyllite n 1: a white or greenish aluminum silicate mineral (resembles talc)