Source : Webster's Revised Unabridged Dictionary (1913)

Phillipsite \Phil"lips*ite\, n. [So named after John Phillips,
   an English mineralogist.] (Min.)
   (a) A hydrous silicate of aluminia, lime, and soda, a
       zeolitic mineral commonly occurring in complex twin
       crystals, often cruciform in shape; -- called also
       {christianite}.

Source : WordNet®

phillipsite
     n : a group of white or reddish crystalline minerals of the
         zeolite family consisting of a hydrous silicate of
         calcium and potassium and aluminum