Found in metamorphosed exhalative sedimentary rocks (banded iron-formations) enclosing the massive Pb-Zn-Cu-Ag sulfide orebodies. The polytype in the type material is 1M. A member o f the Brittle Mica group.
Approved IMA 1999 (Dana # Added)
Broken Hill mine, near Aggeneys, northern Cape Province, South Africa. Link to MinDat.org Location Data.
The name reflects the mineral�s iron content and relationship to kinoshitalite.