Two new mixed-valence iron phosphates, with crystal structures similar to that of the well known synthetic compound Fe7(PO4)6, have been synthesized hydrothermally at 973 K and 0.1 GPa. The structures are characterized by edge-sharing Fe polyhedra forming chains parallel to the  direction. These chains are connected together by Fe3 octahedra and PO4 tetrahedra. FeIII is located in the Fe1 and Fe2 octahedra. Fe3 occurs in a five-coordinated environment and is occupied by FeII, whereas the Fe4 octahedra are occupied by FeII and vacancies.