Where it forms, where it's found
- Geological setting
Subsurface horizon of a Gleysol soil. Partial oxidation and hydrolysis of aqueous Fe2+.
- Type locality
- Fougères Forest
- Fougères
- Fougères-Vitré
- Ille-et-Vilaine
- Brittany
- France
48.3950°, -1.1633°
25recorded occurrences
Physical
- Transparency
- Opaque
- Colour
- Bluish green · green · green-black · blackish
Only when fresh; alters within hours and days
Optical
- UV response
- Not fluorescent.
Crystallography
- Space group
- #99
- Cell parameters
- a = 3.125 Å · c = 22.5 Å
- Type-locality form
Small crystals (400-500 nm) in the form of hexagonal plates.
Crystal structure
Chemical composition
Synonyms
- Fougèriet
- Green Rust
- IMA2003-057
In other languages
- French
- Fougérite · rouille verte
- German
- Fougèrit
- Italian
- fougèrite
- Chinese
- Fe3(OH)8 · 绿锈
Classification
Strunz
10th ed.4.FL.05
- 4OxidesClass
- 4.FHydroxides (without V or U)Division
- 4.FLHydroxides with H2O +- (OH); sheets of edge-sharing octahedraGroup
- 4.FL.05FougèriteSpecies
Dana
8th ed.06.04.06.02
- 06Hydroxides and Oxides Containing HydroxylClass
- 06.04MiscellaneousType
- 06.04.06— unnamed intermediate level —Group
- 06.04.06.02FougèriteSpecies
Group, growth & confusion
Literature, links & citation
Citations
- 1985Nieding, E. (1985) Rezente Mineralbildungen in urzeitlichen Kupferschlacken aus Österreich. Aufschluss: 36: 313–318. (in German)
- 1986Nieding, E. (1986) Pseudohexagonaler Goethit aus einer Schlacke von Lölling/Kärnten. Carinthia II: 176(96): 57–59. (in German)
- 1996Trolard, F., Abdelmoula, M., Bourrie, G., Humbert, B., Genin, J. (1996) Evidence of the occurrence of a 'green rusts' component in hydromorphic soils. Proposed existence of a new mineral fougerite. CRAS (Paris), serie IIa: 232: 1015-1022.
- 1997Blaß, G., Graf, H.-W., Pichler, A. (1997) Sekundäre Neubildungen in Schlacken von St. Martin am Silberberg in Kärnten (2). Mineralien-Welt: 8(6): 54-55. (in German)
- 1997Trolard, F.; Génin, J.-M.R.; Abdelmoula, M.; Bourrié, G.; Humbert, B.; Herbillon, A. (1997) Identification of a green rust mineral in a reductomorphic soil by Mössbauer and Raman spectroscopies. Geochimica et Cosmochimica Acta, 61 (5). 1107-1111 doi:10.1016/s0016-7037(96)00381-xDOI: 10.1016/s0016-7037(96)00381-x
Cite this entry
@misc{mineral2026,
author = {Mineral Index editorial board},
title = {Fougèrite — Mineral Index},
year = {2026},
url = {https://mineralindex.org/minerals/fougerite-27543},
note = {Accessed 2026-05-11}
}