Stanfieldite: a new phosphate mineral from stony-iron meteorites

A new mineral, stanfieldite, Ca(4)(Mg,Fe)(5)(PO(4))(6), has been found in the Estherville mesosiderite and several pallasites: Santa Rosalia, Albin, Finmarken, Imilac, Mount Vernon, and Newport. The atom ratio Mg:Fe of this mineral varies from 1.5 in Estherville to a constant ratio of about 15 in the pallasites. X-ray, optical, and chemical data for the mineral resemble those for the only intermediate compound in the system Mg(3)(PO(4))(2)-Ca(3)(PO(4))(2).