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Clays and Clay Minerals

, Volume 44, Issue 6, pp 744–748 | Cite as

Crystal Structure Modeling of a Highly Disordered Potassium Birnessite

  • Kerry L. Holland
  • Jeffrey R. Walker
Article

Abstract

The structure of a highly disordered synthetic birnessite was studied by comparing powder X-ray diffraction (XRD) data with calculated patterns generated by BIRNDIF and WILDFIRE© in an attempt to describe the nature of disorder and to estimate the size of the coherent diffracting domains. The material has a turbostratic stacking sequence and coherent diffracting domains that are 25 to 30 Å on a side in the ab plane (N1 = 5 unit cells, N2 = 10 unit cells) and which average 2.5 unit cells thick parallel to c. Turbostratic stacking probably results because there are few constraints on the relationship between adjacent layers.

Key Words

Birnessite Crystal Structure Modeling Turbostratic Stacking 

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References

  1. Bish DL, Giese R. 1981. Interlayer bonding in IIb chlorite. Am Mineral 66:1216–1220.Google Scholar
  2. Burns RG, Burns VM. 1976. Mineralogy of ferromanganese nodules. In: GP Glasby, editor. Marine manganese deposits. Amsterdam: Elsevier Science 554 p.Google Scholar
  3. Giovanoli R, Stähl E, Feitknecht W. 1970. Über Oxihydroxides des vierwertigen Mangans mit Schichtengitter, 1. Mitteilung: Natiummangan(II, III)manganat(IV). Helv Chim Acta 53:209–220.CrossRefGoogle Scholar
  4. Moore JN, Walker JR, Hayes TH. 1990. Reaction scheme for the oxidation of As(III) to As(V) by birnessite. Clays Clay Miner 38:549–555.CrossRefGoogle Scholar
  5. Oscarson DW, Huang PM, Liaw WK. 1981. The role of manganese in the oxidation of arsenite by freshwater lake sediments. Clays Clay Miner 29:219–225.CrossRefGoogle Scholar
  6. Post JE, Appleman DE. 1988. Chalcophanite, ZnMn3O7·3H2O: New crystal-structure determinations. Am Mineral 73: 1401–1404.Google Scholar
  7. Post JE, Veblen DR. 1990. Crystal structure determinations of synthetic sodium, magnesium, and potassium birnessite using TEM and the Rietveld method. Am Mineral 75:477–489.Google Scholar
  8. Reynolds RC, Jr. 1985. CLAYDIF: A computer program for the calculation of one-dimensional diffraction patterns of pure clay minerals. Hanover, NH: RC Reynolds, Jr, 8 Brook Rd.Google Scholar
  9. Reynolds RC, Jr. 1993. Three-dimensional X-ray powder diffraction from disordered illite: simulation and interpretation of the diffraction patterns. In: Reynolds RC, Jr, Walker JR, editors. CMS workshop lectures, vol 5, Computer applications to X-ray powder diffraction analysis of clay minerals. Boulder, CO: The Clay Minerals Society, p 43–78.Google Scholar
  10. Reynolds RC, Jr. 1994. WILDFIRE©: A computer program for the calculation of three-dimensional X-ray diffraction patterns for mica polytypes and their disordered variations. Hanover, NH: RC Reynolds, Jr, 8 Brook Rd.Google Scholar
  11. Wadsley AD. 1955. The crystal structure of chalcophanite, ZnMn3O7·3H2O. Acta Crystallogr 8:165–172.CrossRefGoogle Scholar
  12. Wright AC. 1973. A compact representation for atomic scattering factors. Clays Clay Miner 21:489–490.CrossRefGoogle Scholar

Copyright information

© The Clay Minerals Society 1996

Authors and Affiliations

  • Kerry L. Holland
    • 1
  • Jeffrey R. Walker
    • 1
  1. 1.Department of Geology and GeographyVassar CollegePoughkeepsieUSA

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