Schmiederite

Schmiederite is a secondary mineral in the oxidized zone of selenium-bearing hydrothermal base metal deposits. Its chemical formula is Pb₂Cu₂(SeO₃)(SeO₄)(OH)₄.

It was first described in 1962 for an occurrence in the Cóndor mine, Los Llantenes district, Sierra de Cacheuta, La Rioja Province, Argentina (type locality). It was named for Oscar Schmieder (1891–1980), German geographer.