Steinmetzite is a very rare
phosphate mineral with formula Zn2Fe(PO4)2(OH)•3H2O. It was discovered among pegmatites of
Hagendorf in Germany,[2][3] that are famous for rare phosphate minerals.[4] Steinmetzite is chemically related to
phosphophyllite and other
zinciron phosphates, namely
plimerite and
zinclipscombite.[5][6]