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Konferencja
Proceedings of the All-Polish Seminar on Mössbauer Spectroscopy OSSM'04
Języki publikacji
Abstrakty
This paper reports the results of 57Fe Mössbauer study of stilpnomelane K0.6Fe6(Si8Al)(O,OH)27 .2H2O from Żółkiewka (Lower Silesia, Poland). Stilpnomelane in paragenesis with chlorite, tourmaline, claevelandite and zeolites has been found in granite pegmatites in quarries at Żółkiewka. The samples of naturally weathered stilpnomelane and chlorite from the same fragment of rock were also studied. The Mössbauer spectrum of an untreated sample could be fitted to two Fe2+ doublets and two Fe3+ doublets. The Fe2+ doublets have similar isomer shifts, but they distinctly differ in values of quadrupole splittings. Ferric iron, octahedrally coordinated occurs in three different environments represented by two doublets. The first of them, assigned to combined M1 + M2 positions and the second one assigned to M3 site with parameters IS = 0.36 mm/s and QS = 2.07 mm/s is visible in the spectra up to 880°C. This doublet is characteristic of stilpnomelane and can be regarded as a "fingerprint" of this mineral. After heating at 200°C, the relative content of Fe2+, ÓFe2+/ÓFe, decreases to 0.22 what means a 50% decrease in comparison to the initial value observed in the untreated sample. At about 1000°C, complete breakdown of the stilpnomelane structure takes place and the Mössbauer spectrum consists of two sextets and two ferric doublets. Abnormally high content of Fe2+ in naturally weathered stilpnomelane (0.70) comparing to the untreated sample of stilpnomelane (0.45) indicates that the sample had to be subjected to hydrothermal processes operating locally. Almost the same contents of divalent iron and hyperfine parameters of Fe2+ and Fe3+ doublets in weathered stilpnomelane and associated chlorite suggest that the process of chlorite transformation into stilpnomelane seems to be very probable.
Słowa kluczowe
Czasopismo
Rocznik
Tom
Strony
43--48
Opis fizyczny
Bibliogr. 13 poz., rys.
Twórcy
autor
- Faculty of Earth Sciences, University of Silesia, 60 Będzińska Str., 41-200 Sosnowiec, Poland, Tel.: +48 32/ 368 93 70, Fax: +48 32/ 291 58 65
autor
- Institute of Physics, University of Silesia, 4 Uniwersytecka Str., 40-007 Katowice, Poland
autor
- Faculty of Earth Sciences, University of Silesia, 60 Będzińska Str., 41-200 Sosnowiec, Poland, Tel.: +48 32/ 368 93 70, Fax: +48 32/ 291 58 65
Bibliografia
- 1. Bolewski A, Manecki A (1993) Specific character of mineralogy. Wydawnicwo PAE, Warszawa (in Polish)
- 2. Crawford ES, Jefferson DA, Thomas JM (1977) Electronmicroscope and diffraction studies of polytypism in stilpnomelane. Acta Cryst A 33:548−553
- 3. Dollase WA (1973) Mössbauer spectra and iron distribution in the epidote-group minerals. Z Kristallogr 138:41−63
- 4. Eggleton RA (1972) The crystal structure of stilpnomelane. Part II. The full cell. Mineral Mag 38:693−711
- 5. Eggleton RA, Bailey SW (1966) The crystal structure of stilpnomelane. Part I. The subcell. Clays Clay Miner 13:49−63
- 6. Eggleton RA, Chappell BW (1978) The crystal structure of stilpnomelane. Part III. Chemistry and physical properties. Mineral Mag 42:361−368
- 7. Ito J, Hafner SS (1974) Synthesis and study of gadolinites. Am Mineral 59:700−708
- 8. Malczewski D, Janeczek J, Popiel E (1998) Mössbauer studies of fully metamict gadolinite annealed in air. Mol Phys Reports 22:111−116
- 9. Rancourt DG, Dang MZ, Lalonde AE (1992) Mössbauer spectroscopy of tetrahedral Fe3+ in trioctahedral micas. Am Mineral 77:34−43
- 10. Sachanbiński M, Janeczek J (1977) Stilpnomelane from granite pegmatites of the Strzegom-Sobótka Massif. Miner Polon 8;1:3−12
- 11. Taylor GL, Ruotsala AP, Keeling RO (1968) Analysis of iron in layer silicates by Mössbauer spectroscopy. Clays Clay Miner 16:381−391
- 12. Vedder W, Wilkins RWT (1969) Dehydroxylation and rehydroxylation oxidation and reduction of micas. Am Mineral 54:482−509
- 13. Żabiński W, Kraczka J, Pieczka A (1997) Mössbauer studies of Polish axinites. In: Proc of the V School of Minerals Physics. Use of spectroscopic methods in mineralogy and gemmology, Wrocław-Sobótka, 26−28 September 1997.
Typ dokumentu
Bibliografia
Identyfikator YADDA
bwmeta1.element.baztech-article-BUJ6-0006-0010