Feroxyhyte, a new modification of FeOOH

Two modifications of the delta-hydroxide of iron have been synthesized under laboratory conditions. Both are formed topotactically by the rapid course of the abiogenic reaction of the oxidation of Fe+2 at the expense of Fe(OH)2. Natural δ'-FeOOH, for which the authors propose the name "feroxyhyte," was found as yellowish-brown deposits in iron-manganese nodules from the bottom of the Pacific Ocean, Baltic, White, and Kara seas, and in gley soils. Feroxyhyte is an unstable hydrous oxide of iron, apparently transformed spontaneously into goethite, the stable modification of FeOOH. Its theoretical composition is Fe2O3 - 89.86, H2O - 10. 147%.