Image Credit: Malcolm Southwood
Image Credit: Malcolm Southwood
Specimen Title
arsentsumebite after mimetite
Associated Minerals
cerussite; malachite
Principal Mineral
Precursor Mineral
Size
Cabinet; 98mm
Location in the Mine
First oxidation zone
Provenance
Palache, C.
Collection
MGMH; 87174
Entry Number
Specimen; TSNB676
Description
A dense matrix consisting mainly of massive cerussite and arsentsumebite; other arsenates may also be present. Several vugs in the matrix host partial replacements of arsentsumebite after mimetite (Exhibit 2). Preliminary EDS analysis (Martin Števko; Slovak Institute of Sciences, Bratislava, Slovakia) indicates that the replacing mineral is simply arsentsumebite, with no other phases associated. Minor azurite (crystals to 5 mm), malachite after azurite, and free-standing cerussite crystals (to 2 mm) are sparsely associated.
The specimen is from the collection purchased by Charles Palache during his visit to Tsumeb in December 1922, which dates it to the upper part of the first oxidation zone (i.e. 8 Level or above).
