A new Fe(III) oxyhydroxynitrate (FeO(OH)(1-x)(NO3)(x) with 0.2 < x < 0.3) was synthesized which, based on X-ray diffraction, FTIR, and Mossbauer spectroscopy, is considered to have an akaganeite (beta-FeOOH)-like tunnel structure in which nitrate occupies the tunnel. (C) 1996 Academic Press, Inc.