Zhemchuzhnikovite

Zhemchuzhnikovite is an oxalate mineral of organic origin; formula NaMg(FeAl)C2O4·8H2O. It forms smokey green crystals with a vitreous lustre and is found in Russian coal mines. It is named after Yury Zhemchuzhnikov (1885–1957), a Russian clay mineralogist.