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Clays and Clay Minerals

, Volume 35, Issue 1, pp 29–37 | Cite as

Noncrystalline Fe-Si-Al-Oxyhydroxides

  • Richard A. Eggleton
Article

Abstract

High-resolution transmission electron microscopy of noncrystalline Fe-Si-Al-oxyhydroxide gels shows a common structure of hollow packed spheres having external diameters ranging from 50 to 1000 Å. Some sphere walls display a concentric structure, particularly if the gel composition is close to that of a crystalline clay mineral (e.g., smectite, kaolin). The spheres probably formed by expansion of void space (bubbles) as the surrounding gel contracted 5–10% because of partial ordering of the Fe-Si-Al-oxygen network. Much of the water contained in such noncrystalline minerals is incorporated within the bubbles.

Key Words

Gels High-resolution transmission electron microscopy Iron Morphology Noncrystalline oxyhydroxides 

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Copyright information

© The Clay Minerals Society 1987

Authors and Affiliations

  • Richard A. Eggleton
    • 1
  1. 1.Department of GeologyAustralian National UniversityCanberraAustralia

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