Chemistry: [Ca2(H2O)17Ca(H2O)6][Mo8As2Fe3+3O36(OH)]
Size: 35 mm
Owner: W.W. (Bill) Pinch
Photographer: John Schneider

Tsumeb mineralogist John Innes collected this specimen of betpakdalite from the E9 Stope on 30 Level, in the second oxidation zone, on July 19, 1984.

A bright yellow, microcrystalline crust of betpakdalite-CaCa (analytically confirmed) partly encrusts a matrix consisting largely of tennantite and quartz. 

The label history accompanying this specimen is interesting because it documents a route followed by much of the Innes collection material.  John Innes died in Western Australia in 1992.  Some of the more aesthetic specimens from his collection were cherry-picked by two major dealers, but the blance was sold to Australian collector Blair Gartrell, of the (privately owned) Westaus Mineral Museum.  After Gartrell's death in 1996, much of the material was acquired by Rob Sielecki (of Ausrocks) who dispersed it to the wider mineral community.  This specimen is now in the collection of Bill Pinch and, importantly, the preservation of John Innes' hand-written label allows us to see exactly when and where it was collected.