Source : Webster's Revised Unabridged Dictionary (1913)

Zeolite \Ze"o*lite\, n. [Gr. ? to boil + -lite: cf. F.
   z['e]olithe.] (Min.)
   A term now used to designate any one of a family of minerals,
   hydrous silicates of alumina, with lime, soda, potash, or
   rarely baryta. Here are included natrolite, stilbite,
   analcime, chabazite, thomsonite, heulandite, and others.
   These species occur of secondary origin in the cavities of
   amygdaloid, basalt, and lava, also, less frequently, in
   granite and gneiss. So called because many of these species
   intumesce before the blowpipe.

   {Needle zeolite}, needlestone; natrolite.

Source : WordNet®

zeolite
     n : any of a family of glassy minerals analogous to feldspar
         containing hydrated aluminum silicates of calcium or
         sodium or potassium; formed in cavities in lava flows and
         in plutonic rocks