Citation: Burns, P. C.; Hawthorne, F. C. (1995). The crystal structure of sinkankasite, a complex heteropolyhedral sheet mineral Locality: Barker pegmatite, near Keystone, Pennington County, South Dakota, USA. American Mineralogist, 80, pp. 620-627.
Formula: Al H15 Mn O15 P2
List type: noninterleaving
List: 2D
Basis: (0;1;0 0;0;1)
Dimensionality: 2
Formula: Al2 H22 Mn2 O26 P4 (Al H11 Mn O13 P2)
Multiplicity: 1