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Pyrophanite from Chvaletice (Bohemia)

Published online by Cambridge University Press:  05 July 2018

L. Žák
L. Žák*
Affiliation:
Department of mineralogy, geochemistry, and crystallography, Charles University, Prague, Czechoslovakia
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Summary

Pyrophanite was found in quartz-rhodochrosite veins in hornstones of Algonkian pyritemanganese ores. Photometric reflectance falls from R0 24 and RE′ 19 at 405 mµ to R0 18 and RE′ 15% at 656 mµ (in air). Vickers microhardness (100 g load) demonstrates directional anisotropy, the average value is 611 kg/mm2. Besides the main constituents, subordinate to trace quantities of Mg, Si, Al, Ca, and Cu were recorded by a spectrographic analysis. Unit-cell dimensions are a = 5·131 and c = 14·27 Å. Electron-microprobe analysis gave MnO 43·3, FeO 3·8, MgO 0·05, TiO2 52·9, SiO2 0·1, total 100·15%. The origin of the Chvaletice pyrophanite was most probably connected with a hydrothermal metamorphism of an Alpine-paragenesis type. The source of elements was older sedimentary, basic volcanic, and metamorphic mineral assemblages.

Type
Research Article
Information
Mineralogical Magazine , Volume 38 , Issue 295 , September 1971 , pp. 312 - 316
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1971

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References

Birks, (L.S.), 1963. Electron Probe Microanalysis. New York and London.Google Scholar
[Chukhrov, (F. V.) and Bonshtedt-Kupletskaya, (E. M.)] (Minerals), 2, no. 3, 275-8.Google Scholar
Gomes, (C. DE BARROS), 1969. Amer. Min. 54, 1654-61.Google Scholar
Hamberg, (A.), 1890. Geol. För. Förh. 12, 598-604.Google Scholar
Hartman, (P.), 1969. Min. Mag. 37, 366-9 [M.A. 20-310].CrossRefGoogle Scholar
Ishikawa, (Y.) and Akimoto, (S.), 1958. Journ. Phys. Soc. Japan, 13, 1110-18.CrossRefGoogle Scholar
Lee, (D.S.), 1955. Amer. Min. 40, 32–40 [M.A. 13-596].Google Scholar
Neumann, (H.) and Bergstol, (S.), 1964. Norsk Geol. Tidsskr. 44, 39–42 [M.A. 16-643 ].Google Scholar
Posnjak, (E.) and BARTH (T. F. W.), 1934. Zeits. Krist. 88, 271-80 [M.A. 6-45 ].Google Scholar
Portnov, (A. M.)] (Compt. Rend. Aead. Sci. URSS), 153, 187-9 [M.A. 18-201].Google Scholar
Shirane, (G.), Pickart, (S.J.), and Ishikawa, (Y.), 1959. [Journ. Phys. Soc. Japan, 14, 1352]; abstr. in WYCKOFF (R. G. W.), 1964, Crystal Structures, 2, 422. New York, London, and Sydney.Google Scholar
Smith, (W. CAMPBELL) and CLARINGBULL, (G.F.), 1947. Min. Mag. 28, 108-10.Google Scholar
Springer, (G.), 1966. Neues Jahrb. Min. Montash. 113-25 [M.A. 18-77].Google Scholar
Springer, (G.), 1967. Fortschr. Min. 45, 103-24 [M.A. 20-6].Google Scholar
Svoboda, (J.) and Fiala, (F.), 1951. véstnik Ústřed. úst. geol. 26, 114-20.Google Scholar
Žák, (L.), 1965. Cas. Min. Geol 10,495.Google Scholar
Žák, (L.), 1967. Ibid. 12, 451-2.Google Scholar