zinnwaldite

from WordNet (r) 3.0 (2006)

zinnwaldite
    n 1: a mica containing iron and lithium

from The Collaborative International Dictionary of English v.0.48

Zinnwaldite \Zinn"wald*ite\, n. [So called after Zinnwald, in
   Bohemia, where it occurs.] (Min.)
   A kind of mica containing lithium, often associated with tin
   ore.
   [1913 Webster]