Source : Webster's Revised Unabridged Dictionary (1913)

Damourite \Dam"our*ite\ (d[a^]m"[oo^]*[imac]t), n. [Ater the
   French chemist Damour.] (Min.)
   A kind of Muscovite, or potash mica, containing water.

Source : WordNet®

damourite
     n : a variety of muscovite