page_title: Mottramite
section_title: Appearance
hierarchical_section_title: Mottramite / Appearance
caption_attribution_description: English: Calcite Locality: Tsumeb Mine (Tsumcorp Mine), Tsumeb, Otjikoto (Oshikoto) Region, Namibia (Locality at mindat.org) A unique specimen, so richly included with dendritic mottramite that there might even be more mottramite than calcite inside of it! I think the pics pretty much show how interesting, colorful, and dramatic it is...both sides are pristine, and shown in the images. Moreover, it is a floater. 5 x 4.5 x 3 cm Deutsch: Calcit Fundort: Tsumeb Mine (Tsumcorp Mine), Tsumeb, Region Otjikoto (Oshikoto), Namibia (Fundort bei mindat.org)
context_page_description: Mottramite is an orthorhombic anhydrous vanadate hydroxide mineral, PbCu, at the copper end of the descloizite subgroup. It was formerly called cuprodescloizite or psittacinite. 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.
context_section_description: Drusy crusts of tiny intergrown crystals are common, also encrustations and mammillary or botryoidal surfaces.  The crystals are equant dipyramids or prisms parallel to the c crystal axis, but always microscopic.  The colour is various shades of green, yellow-green, blackish brown or nearly black. Crystals often grow step by step, with the different steps or zones having different colours.  The streak is yellowish green, or yellow, and the crystals are transparent to opaque, with a greasy lustre.
caption: Calcite (white) covered by green mottramite from Tsumeb, Namibia
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