Structure of fougerite and green rusts and a thermodynamic model for their stabilities

Fabienne Trolard (1) , Guilhem Bourrie (1)

1 URGSE - Unité de recherche Géochimie des Sols et des Eaux

Fougerite is a new iron oxide, a mixed M(II)–M(III) hydroxide, a member of the green rust group. Its structure consists of a brucitic layer of Fe(III)–Fe(II)–Mg(II), where the excess of the positive charge due to Fe3+ is compensated in the interlayer by anions. The limits of composition are structurally and geochemically constrained, and the stabilities of the mineral and green rusts are obtained by a thermodynamic model of a regular solid solution, for different compensating anions and for any allowed composition of the brucitic layer

Mots clés: FE; GREEN RUSTS; THERMODYNAMICS; GEOCHIMIE

Mots clés: IRON OXIDE; MINERALOGIE

Domaines: Géochimie

Fabienne Trolard, Guilhem Bourrie. Structure of fougerite and green rusts and a thermodynamic model for their stabilities. Journal of Geochemical Exploration, 2006, 88 (1-3), pp.249-251. ⟨10.1016/j.gexplo.2005.08.048⟩. ⟨hal-02667649⟩