Mottramite is an orthorhombic anhydrous vanadate hydroxide mineral, PbCu(VO4)(OH), at the copper end of the descloizite subgroup.

It was formerly called cuprodescloizite or psittacinite (this mineral characterized in 1868 by Frederick Augustus Genth).

Duhamelite is a calcium- and bismuth-bearing variety of mottramite, typically with acicular habit.

[3][5][7] Mottramite is an orthorhombic mineral belonging to the crystal class 2/m 2/m 2/m, with space group Pnma.

[3][4][5] The structure is composed of chains of edge-sharing CuO6 octahedra and very distorted Pb(O,OH)8 polyhedra linked through VO4 groups into a tight three-dimensional network.

[4] Drusy crusts of tiny intergrown crystals are common, also encrustations and mammillary or botryoidal surfaces.

[3] The streak is yellowish green,[3][5] or yellow,[7] and the crystals are transparent to opaque,[3][4][5] with a greasy lustre.

[3][5] Mottramite is a secondary, supergene mineral found principally in the oxidized zones of vanadium bearing base metal deposits,[3][4][5] especially sandstones.

[4] Associated minerals are descloizite, duftite, mimetite, wulfenite, cerussite, azurite and dioptase.