Synthetic mansfieldite,AlAsO4·2H2O

Hydro­thermally prepared mansfieldite, AlAsO₄·2H₂O (aluminium arsenate dihydrate), contains a vertex‐sharing three‐dimensional network of cis‐AlO₄(H₂O)₂ octahedra and AsO₄ tetrahedra d_av(Al—O) = 1.907 (2) Å, d_av(As—O) = 1.685 (2) Å and θ_av(Al—O—As) = 134.5 (1)°].