ojuelaite (w. schneiderhöhnite, scorodite etc.)

Partly oxidised sulphide mineralisation with quartz and siderite in altered dolostone (?). The mineralised portion of the rock is vuggy and hosts a complex paragenesis.

The major vug hosts crystals of transparent yellow siderite, partly encrusted by goethite. The siderite appears to be post-dated by scorodite (blue) and platy black schneiderhöhnite. Ojuelaite (XRD verified) occurs as a < 1 mm sub-spheical radiating spray of acicular yellowish to olive-green crystals associated with gemmy blue scorodite and elsewhere as sub-parallel groups of acicular crystals (Exhibit 2). A rash of minute yellow "spots" on the schneiderhöhnite may also be ojuelaite but this has not been confirmed. Arseniosiderite occurs as buff-coloured coatings on quartz (?) and siderite (?).

A little leiteite and ludlockite are locally developed on a parting in the sulphide mineralisation but not directly associated with the other secondary minerals.

The location in the mine is not recorded but the paragenesis is strongly indicative of the second oxidation zone.

The specimen was number 2834 in the collection of Austrian collector Franz Lammer (1914-1997) who purchased it from Peter Rath, in Tsumeb, in 1984. The Lammer Collection was dispersed by Ian Bruce (Crystal Classics) in 2015. The specimen  is accompanied by two Lammer labels (exhibits 3 and 4) and by a note indicating that the scorodite was verified by XRD at the Landesmuseum Joanneum, in Graz, Austria (Exhibit 5).

arseniosiderite; goethite; hematite; leiteite; ludlockite; quartz; schneiderhöhnite; scorodite; siderite