Mineralpedia Details for Tsumcorite
Named for The Tsumeb Corporation for their contributions to investigations of the Tsumeb orebody in Namibia, and quite possibly named after the Tsumcorp mine from which Tsumcorite gets its type locality. It is a rare secondary mineral in some arsenic-bearing, hydrothermal, leas-zinc deposits and occurs in the oxidized zones of these deposits. It can be found in a few localities in North America, Europe, and Africa.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/tsumcorite.pdf
Tsumcorite from Tsumeb mine, Tsumeb, Namibia
Thousands of mustard yellow, bowtie-like sprays of Tsumcorite. Tsumeb is the standard for this species. These are from the 2nd oxidation zone in the Tsumeb mine.
Also a specimen with well-defined Tsumcorite as singles and clusters gracing the the Wulfenite crystals.