Citation: Giuseppetti, G.; Mazzi, F.; Tadini, C. (1977). The crystal structure of harkerite. American Mineralogist, 62, pp. 263-272.
Formula: C8 H Al2 B8 Ca24 Cl Mg8 O81 Si8
List type: noninterleaving
List: 3D
Basis: (1;0;0 0;1;0 0;0;1)
Dimensionality: 3
Formula: Al2 B8 Mg8 O56 Si8 (Al B4 Mg4 O28 Si4)
Multiplicity: 1
Coordination sequences: