[Al(H(2)O)(6)][Cr(OH)(6)Mo(6)O(18)]·10H(2)O

The title compound, [Al(H(2)O)(6)][Cr(OH)(6)Mo(6)O(18)]·10H(2)O, hexa­aqua­aluminium hexa­hydroxidoocta­deca­oxido­molybdo­chromate(III) deca­hydrate, crystallizes isotypically with its gallium analogue [Ga(H(2)O)(6)][Cr(OH)(6)Mo(6)O(18)].10H(2)O. In the structure of the title compound, both the [Al(H(2)O)(6)](3+) cation and the Anderson-type [Cr(OH)(6)Mo(6)O(18)](3−) anion lie on centres of inversion. The anion is composed of seven edge-sharing octa­hedra, six of which are MoO(6) octa­hedra that are arranged hexa­gonally around the central Cr(OH)(6) octa­hedron. The anions are linked to each other by O—H⋯O hydrogen bonds into infinite chains along [100]. These chains are further connected with the [Al(H(2)O)(6)](3+) cations through O—H⋯O hydrogen bonds into sheets parallel to (01[Image: see text]). O—H⋯O hydrogen bonds involving all the lattice water mol­ecules finally link the sheets into a three-dimensional network.