Wulfenite (w. tsumcorite (?))

goethite; quartz; tsumcorite (?); undetermined

A vuggy matrix of partly oxidised massive sulphide. All vugs are lined with goethite and some of them host etched-looking quartz crystals, crusts of bright yellow tsumcorite (?) and thick, tabular crystals (to 7 mm) of butterscotch-coloured wulfenite (Exhibit 2). Minute acicular crystals of an undetermined green mineral are also present (though not discernible in these photographs).

XRD analysis (Mintek; Randburg, South Africa, 1984) confirms that the yellow mineral is a member of the tsumcorite group; its composition has not been determined, but the colour, habit and paragenesis are consistent with tsumcorite (?).

The specimen was purchased from Klaus Rühland in Windhoek, Namibia, in 1984. The location in the mine is not recorded but the paragenesis is strongly indicative of the second oxidation zone.