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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.〔 Mottramite is a member of the adelite-descloizite group.〔 Mottramite, which is a copper rich member, forms a series with descloizite, which is a zinc rich member.〔〔 These two minerals usually contain significant percentages of both copper and zinc and are seldom pure. Mottramite also forms a series with duftite.〔 It was discovered in 1876〔 and named for the locality, Mottram St Andrew, Cheshire, England, where ore was stockpiled, although it was probably mined from Pim Hill Mine, Shrewsbury, Shropshire, England.〔Kingsbury and Hartley (1956). New occurrences of vanadium minerals (mottramite, descloizite, (discredited) and vanadinite) in the Caldbeck area of Cumberland. Mineralogical Magazine 31:289〕〔〔 == Crystallography == Mottramite is an orthorhombic mineral belonging to the crystal class 2/m 2/m 2/m, with space group Pnma.〔〔〔 The unit cell has sides of lengths a = 7.6 to 7.7 Å, b = 9.2 to 9.5 Å and c = 6.0 to 6.1 Å.〔〔〔〔Van der Westhuizen, de Bruiyn, Tordiffe and Botha (1986). The descloizite-mottramite series of vanadates from the Otavi Mountain Land, South West Africa: an X-ray study. Mineralogical Magazine 50:137〕 There are four formula units per unit cell (Z = 4), the molar mass is 402.69 g〔 and the calculated density is 6.19 g/cm3.〔〔〔 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.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Mottramite」の詳細全文を読む スポンサード リンク
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