Summary
Room-temperature Mössbauer spectra of five iron-bearing tourmalines were measured and analyzed. The Fe2+/Fe3+ ratio and the iron occupancy of the Y and Z positions could be assigned to all samples, with the help of two previously well characterized samples, from Mexico and Madagascar. Ferric or ferrous ions or both partially occupy the Z as well as the Y octahedra. This fact of observation is interpreted as the chemical response, during crystal growth, to the requirement of size matching for the edge-sharing Y and Z oxygen octahedra. It accounts for the inexistence of solid solution between the Mg and (Li, Al) tourmalines.
Zusammenfassung
Mössbauer-Spektren von fünf eisenhaltigen Turmalinen wurden gemessen und analysiert. Das Verhältnis Fe2+/Fe3+ und die Eisenverteilung konnten mit Hilfe von zwei gut identifizierten Turmalin-Kristallen von Mexiko und Madagascar für die Y-und Z-Lagen aller Exemplare bestimmt werden. Zweiwertiges sowie dreiwertiges Eisen findet sich sowohl in der Z-als auch in der Y-Lage. Da sich die Y-und Z-Oktaeder in einer gemeinsamen Kante treffen, wird diese Beobachtung als chemische Antwort des Kristalles auf die erforderte Größenanpassung der Y-und Z-Oktaeder während seines Wachstums erklärt. Die Abwesenheit der festen Lösung zwischen Dravit und Elbait kann somit erklärt werden.
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References
Barton, R., Jr., 1969: Refinement of the crystal structure of buergerite and the absolute orientation of tourmalines. Acta Cryst.B25, 1524–1533.
Buerger, M. J., C. W. Burnham, andD. R. Peacor, 1962: Assessment of the several structures proposed for tourmaline. Acta Cryst.15, 583–590.
Burns, R. G., 1972: Mixed valencies and site occupancies from iron in silicate minerals from Mössbauer spectroscopy. Canad. J. Spectr.17, 51–59.
Donnay, G., andR. Barton, Jr., 1972: Refinement of the crystal structure of elbaite and the mechanism of tourmaline solid solution. Tschermaks Min. Petr. Mitt.18, 273–286.
Frondel, C., A. Biedl, andT. Ito, 1966: New type of ferric tourmaline. Amer. Min.51, 1501–1505.
Lehrman, A., M. Stiller, andE. Hermon, 1968: Mössbauer quantitative analysis of Fe3+/Fe2+ ratios in some phosphate and oxide mixtures: possibilities and limitations. Earth Planet. Science Letters3, 409–416.
Manning, P. G., 1969: Optical absorption spectra of chromium-bearing tourmaline, black tourmaline and buergerite. Canad. Min.10, 57–70.
Mason, B., G. Donnay, andL. A. Hardie, 1964: Ferric tourmaline from Mexico. Science144, 71–73.
Smith, D. L., andJ. J. Zuckerman, 1967: Sn119m Mössbauer spectra of tin-containing minerals. J. Inorg. Nucl. Chem.29, 1203–1210.
Tippe, A., andW. C. Hamilton, 1971: A neutron-diffraction study of the ferric tourmaline buergerite. Amer. Min.56, 101–113.
Tsang, T., A. N. Thorpe, G. Donnay, andF. E. Senftle, 1971: Magnetic susceptibility and triangular exchange coupling in the tourmaline mineral group. J. Phys. Chem. Solids32, 1441–1448.
Wilkins, R. W. T., E. F. Farrel, andC. S. Naiman, 1969: The crystal field spectra and dichroism of tourmaline. J. Phys. Chem. Solids30, 43–56.
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Hermon, E., Simkin, D.J., Donnay, G. et al. The distribution of Fe2+ and Fe3+ in iron-bearing tourmalines: A Mössbauer study. TMPM Tschermaks Petr. Mitt. 19, 124–132 (1973). https://doi.org/10.1007/BF01082791
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DOI: https://doi.org/10.1007/BF01082791