Arsentsumebite (illustrated as Tsumebite)
Tsumeb mine, Tsumeb, Otjikoto region, , Namibia
Miniature, 3.7 x 2.9 x 2.6 cm
Ex. F. John Barlow
A rich specimen of dark emerald-green arsentsumebite from the type locality. A corner of the piece contains a clustering of numerous <0.5mm scintillating crystals with the remainder of the piece complimented by rich coatings and veinlets of this lead copper arsenate-sulfate. The color is so dark, that it is easy to see why it was assumed to be tsumebite, 30 years ago. This piece was featured in "The F. John Barlow Mineral Collection" as tsumebite (illustrated on page 307!); however, subsequent analysis upon our acquisition of the piece revealed it to be arsentsumebite. An important (mis)figured specimen of a very rare species.