Chemistry: BaSO4
Size: 80 mm
Owner: Mark Feinglos
Photographer: Steven Conlon (DUMC Photopath)

Colourless, modified rhombs of smithsonite (to 7 mm), and sparse, tabular orange-brown crystals of baryte (to 4 mm), on a plate of anhedral, yet well-crystallised quartz. Under magnification (see close-up) the quartz shows what appears to be a semi-regular arrangement of growth plates.

Baryte is an uncommon mineral at Tsumeb, although it is well-documented from the first oxidation zone, where it is typically associated with quartz or smithsonite; however, it is somewhat unusual to find both of these associates on the same specimen. The handwritten label (in German) confirms that this is an old specimen which, at the time, was more highly prized for the smithsonite than for the much rarer baryte.