'Heulandite' definitions:

Definition of 'heulandite'

From: WordNet
noun
A group of minerals of the zeolite family consisting of a hydrous aluminum silicate of sodium and calcium

Definition of 'Heulandite'

From: GCIDE
  • Heulandite \Heu"land*ite\, n. [After Heuland, an English mineralogist.] (Min.) A mineral of the Zeolite family, often occurring in amygdaloid, in foliated masses, and also in monoclinic crystals with pearly luster on the cleavage face. It is a hydrous silicate of alumina and lime. [1913 Webster]