paragonite

from WordNet (r) 3.0 (2006)

paragonite
    n 1: a colorless or pale brown mica with sodium

from The Collaborative International Dictionary of English v.0.48

Paragonite \Pa*rag"o*nite\, n. [From Gr. ?, p. pr. of ? to
   mislead.] (Min.)
   A kind of mica related to muscovite, but containing soda
   instead of potash. It is characteristic of the paragonite
   schist of the Alps.
   [1913 Webster]