What is "tsumcorite"

n. (context mineralogy English) A monoclinic-prismatic mineral containing arsenic, hydrogen, iron, lead, oxygen, and zinc.

Tsumcorite is a rare hydrated lead arsenate mineral that was discovered in 1971, and reported by Geier, Kautz and Muller. It was named after the TSUMeb CORporation mine at Tsumeb, in Namibia, in recognition of the Corporation’s support for mineralogical investigations of the orebody at its Mineral Research Laboratory.