Citation: Merkle, A. B.; Slaughter, M. (1967). The crystal structure of heulandite (Ca,Na2)[Al2Si7O18].6H2O. American Mineralogist, 52, pp. 273-276.
Formula: Al1.602 Ca H11.333 O16.002 Si4.398
List type: noninterleaving
List: 3D
Basis: (1;0;0 0;1;0 0;0;1)
Dimensionality: 3
Formula: Al36 O80 Si36 (Al9 O20 Si9)
Multiplicity: 1