Janggunite
# Janggunite

Janggunite is a rare manganese oxide mineral with the chemical formula $Mn_{5−x}(Mn,Fe)_{1+x}O_8(OH)_6.$

It was first described in 1975 for an occurrence in the Janggun mine, Bonghwa-gun, Gyeongsangbuk-do, South Korea and named for the locality.

