Wulfenite, (w. Anglesite)

Mineral: Wulfenite, Anglesite
Chemistry: PbMoO4
Size: 36 mm
Owner: Crystal Classics
Photographer: Crystal Classics

Steeply pyramidal crystals of blue-black wulfenite (to 10 mm) associated with white to pale-green anglesite.  The local green colouration in the anglesite appears to be due to inclusions of an unidentified copper secondary mineral, a small remnant of which adheres to one surface of the specimen (Photograph 3).  (The vertical FOV for the two close-up images is c. 15 mm.)

This is an unusual habit of wulfenite, that is sometimes described by the varietal name of chillagite, a tungstate-rich variety of the mineral first described from Chillago, in Queensland, Australia.  However, Embrey et al. (1977) point out that the habit of the Tsumeb material is different, and that the WO3 content is much lower than the Australian material.