mottramite

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.

Key facts

Mineral.name: Mottramite
Mineral.image: Mottramite-174237.jpg
Mineral.imagesize: 260px
Mineral.category: Vanadate minerals
Mineral.formula: PbCu(VO4)(OH)
Mineral.IMAsymbol: Mott
Mineral.molweight: 402.69 g/mol
Mineral.strunz: 8.BH.40
Mineral.dana: 41.5.2.2
Mineral.system: Orthorhombic
Mineral.class: Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Mineral.symmetry: Pnma
Mineral.unit cell: a = 7.68 Å, b = 9.27 Å, c = 6.03 Å; Z = 4
Mineral.colour: Grass-green, olive-green, yellow-green, siskin-green, blackish brown, nearly black
Mineral.habit: Encrustations, aggregates of plume-like forms and radial crystals
Mineral.cleavage: None observed
Mineral.fracture: Irregular/uneven, sub-conchoidal
Mineral.tenacity: Brittle

via Wikipedia infobox

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Encyclopedic overview

7 sections

Contents

Crystallography
Appearance
Physical properties
Optical properties
Occurrence
Localities
References

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.

Excerpted from Wikipedia’s “mottramite” article, available under the CC BY-SA 4.0 licence.