The hureaulite group includes: hureaulite: Mn2+5(PO3OH)2(PO4)2.4H2O sainfeldite: Ca5(AsO4)2(AsO3OH)2.4H2O villyaellenite: (Mn,Ca)Mn2Ca2(AsO3OH)2(AsO4)2.4H2O Back to Minerals