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Diffuse reflectance spectra and optical properties of some iron and titanium oxides and oxyhydroxides

Published online by Cambridge University Press:  05 July 2018

R. G. J. Strens  and
B. J. Wood
R. G. J. Strens
Affiliation:
School of Physics, The University, Newcastle upon Tyne NE1 7RU
B. J. Wood
Affiliation:
Department of Geology, The University, Manchester M13 9PL
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Summary

The reliability and utility of diffuse reflectance spectra are briefly but critically reviewed. The results of measurements of diffuse reflectance over the wavelength range 200 < λ < 2500 nm are reported for wüstite, magnetite, hematite, maghemite, ilmenite, ulvöspinel, and α-FeO · OH (goethite), β-FeO 7sd OH, γ-FeO · OH (lepidocrocite), and δ-FeO · OH. The spectra have been assigned by reference to simplified molecular-orbital energy-level diagrams derived from recent SCF-Xα calculations.

The specular reflectances reported in the Quantitative Data File (Henry, 1977) are related to the diffuse reflectance spectra in a rational way. Minerals that absorb strongly throughout the visible display little dispersion of specular reflectance, and their powders are dark (wüstite, magnetite, ilmenite, ulvöspinel); those that absorb much more strongly in the near ultraviolet than in the visible have specular reflectances that decrease monotonically from blue to red according to a simple dispersion relation derived by combining the Sellmeier dispersion and Fresnel reflexion equations; their powders are strongly coloured (hematite, maghemite, lepidocrocite, goethite) and their optical anisotropy is closely related to crystal structure.

Type
Research Article
Information
Mineralogical Magazine , Volume 43 , Issue 327 , September 1979 , pp. 347 - 354
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1979

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Footnotes

1

Present address: Department of Mineralogy and Petrology, Downing Place, Cambridge CB2 3EW.

References

Henry, (N. F. M.), ed., 1977. Quantitative Data File of the IMA-COM. McCrone, London.Google Scholar
Koritnig, (S.), 1962. In Landolt-Börnstein Zahlenwerte und Funktionen, lI Band, 8 Teil (Optische Konstanten). Springer-Verlag, Berlin.Google Scholar
Smith, (G.), 1978. Phys. Chem. Minerals. 3, 375.CrossRefGoogle Scholar
Smith, (G.) and Strens, (R. G. J.), 1976. In Strens, (R. G. J.), ed. The Physics and Chemistry of Minerals and Rocks. Wiley, London and New York.Google Scholar
Strens, (R. G. J.) and Freer, (R.), 1978. Mineral. Mag. 42, 19.Google Scholar
Tossell, (J. A.), 1978. Phys. Rev. B. 17, 484.CrossRefGoogle Scholar
Tossell, (J. A.) Vaughan, (D. J.), and Johnson, (K. J.), 1973. Nature Phys. Sci. 244, 42.CrossRefGoogle Scholar
Tossell, (J. A.) Vaughan, (D. J.), and Johnson, (K. J.) 1974. Am. Mineral. 59, 319.Google Scholar
Wendlandt, (W. W.) and Hecht, (H. G.), 1966. Reflectance Spectroscopy. Wiley, London and New York.Google Scholar
Wood, (B. J.), 1971. Ph.D. thesis, University of Newcastle upon Tyne.Google Scholar
Wood, (B. J.) and Strens, (R. G. J.), 1970. Abstracts, IMA-IAGOD Meeting (Tokyo), 116.Google Scholar