molybdofornacite (w. dioptase)

calcite; dioptase; duftite; goethite; quartz

A siliceous but cavernous matrix, quite heavily iron-stained, is richly encrusted with bluish-green dioptase crystals (to circa 5 mm). Molybdofornacite occurs as localised aggregates of twinned, lath-shaped microcrystals (to circa 1.5 mm), highly translucent and bright lime-green in colour (Exhibit 2). Iron-stained calcite, goethite and a little pistachio-green duftite are also present as accessory minerals.

This specimen was collected by Tsumeb Corporation mineralogist John Innes in the early 1980s and is number JI-182 in the unpublished catalogue of the Innes collection prepared by Ernie Nickel in the early 1990s. Nickel confirmed the molybdofornacite by XRD at the CSIRO laboratories in Perth, Western Australia, analysis number A10376, which appears in both the catalogue and on the label of its subsequent owners, Balir and Robyn Gartrell (Exhibit 3). Following Gartrell's untimely death in 1994, the specimen passed to Australian dealer Rob Sielecki from whom it was purchased by the late Bill Pinch. The Pinch Collection label (Exhibit 4) records the location in the mine as 30 Level, South 110 which is consistent with that given for similar specimens from the Innes Collection but, unfortunately, the original Innes label appears to have been misplaced.