Arsentsumebite Pseudo. After Mimetite
Tsumeb Mine, Namibia, Africa
Miniature, 5.6 x 4.3 x 2.9 cm
Ex. Dr. Gary Hansen

An exceptionally rare and rich, very old-time specimen! When I got it in the Hansen collection labeled as a pyro (but never checked by analysis), it had me puzzled. Pyromorphite is not reported in crystalline form of any quality from Tsumeb and this would have been a miraculous piece. Further study has confirmed it is actually arsentsumebite pseudomorph after mimetite, which makes more sense mineralogically as well as in terms of the crystal form present (which wasn't hexagonal). The piece is exceedingly rich, then, for this very rare species. Despite a few broken crystals, it is also very showy and displayable. Specimens of this type were reported to have been found in the upper oxidation zone, and so it most likely dates to 75 years or more in age. Significant and rare! Just not a pyro...