Abstract
Particularly interesting chemical variability in the U4+ phosphate mineral vyacheslavite from Menzenschwand (Germany) has been discovered and investigated by means of electron-diffraction and micro-chemical methods. Suggested variability comprises the elevated contents of calcium and rare-earth elements (REEs or Ln). Based on the crystal structure refinement from 3D electron diffraction data, the structural formula of Ca-rich vyacheslavite studied is U0.895Ca0.105 PO4(OH)0.790(H2O)0.210. In general, such compositional variability involving Ca2+ can be expressed as U1–x CaxPO4(OH)1–2x(H2O)2x. Based on detailed electron-probe microanalysis, regions extremely enriched in Y and Ln have been discovered, characterized by the contents up to 11 wt% of Y2O3 and ~4.5 wt% of Ln2O3. In addition to the above-mentioned substitution mechanism, substitution involving Y and Ln can be expressed as U4+ + OH– → REE3+ + H2O. Although the structure refinement has not provided direct evidence of H2O in the studied nano-fragments of vyacheslavite, the presence of H2O and its substitution at OH– sites is a reasonable and necessary charge-balancing mechanism. One H atom site was located during structure refinements; however, an additional H-site is only partially occupied and thus was not revealed from the refinement despite the high-quality data. Substitutional trends observed here suggest possible miscibility or structural relationship between vyacheslavite, rhabdophane, and ningyoite that may depend strongly on OH/H2O content, considering that all crystallize under similar paragenetic conditions.
Funding statement: This study was funded by the Czech Science Foundation (GACR 20-11949S to G.S. and J.P.), and by OP VVV project (Geobarr CZ.02.1.01/0.0/0.0/16_026/ 0008459 to R.S.)
Acknowledgments
We express our thanks to Stephan Wolfsried (Waiblingen, Germany) and Carsten Slotta (Hausach, Germany) for their kind cooperation in providing us with the specimens used in this research project. The earlier version of the manuscript greatly benefited from the constructive reviews of an anonymous referee and Travis Olds.
References cited
Alexandre, P., Kyser, K., Layton-Matthews, D., Joy, B., and Uvarova, Y. (2015) Chemical compositions of natural uraninite. Canadian Mineralogist, 53, 595–622.10.3749/canmin.1500017Search in Google Scholar
Belova, L.N., Gorshkov, A.I., Ivanova, O.A., Sivtsov, A.V., Lizorkina, L.I., and Voronikhin, V.A. (1984) Vyacheslavite U4+(PO4)(OH)·nH2O—A new uranium phosphate. Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva, 113, 360–365.Search in Google Scholar
Burns, P.C., Finch, R.J., Hawthorne, F.C., Miller, M.L., and Ewing, R.C. (1997) The crystal structure of ianthinite,
Deditius, A.P., Utsunomiya, S., and Ewing, R.C. (2008) The chemical stability of coffinite, USiO4·nH2O; 0 < n < 2, associated with organic matter: A case study from Grants uranium region, New Mexico, U.S.A. Chemical Geology, 251, 33–49.10.1016/j.chemgeo.2008.02.009Search in Google Scholar
Deditius, A.P., Utsunomiya, S., Wall, M.A., Pointeau, V., and Ewing, R.C. (2009) Crystal chemistry and radiation-induced amorphization of P-coffinite from the natural fission reactor at Bangombé, Gabon. American Mineralogist, 94, 827–837.10.2138/am.2009.3114Search in Google Scholar
Doinikova, O.A. (2007) Uranium deposits with a new phosphate type of blacks. Geology of Ore Deposits, 49, 80–86.10.1134/S1075701507010047Search in Google Scholar
Gemmi, M., and Lanza, A.E. (2019) 3D electron diffraction techniques. Acta Crystallographica, B75, 495–504.10.1107/S2052520619007510Search in Google Scholar PubMed
Gemmi, M., Mugnaioli, E., Gorelik, T.E., Kolb, U., Palatinus, L., Boullay, P., Hovmöller, S., and Abrahams, J.P. (2019) 3D electron diffraction: The nano-crystallography revolution. ACS Central Science, 5, 1315–1329.10.1021/acscentsci.9b00394Search in Google Scholar PubMed PubMed Central
Göb, S., Wenzel, T., Bau, M., Jacob, D.E., Loges, A., and Markl, G. (2011) The redistribution of rare-earth elements in secondary minerals of hydrothermal veins, Schwarzwald, southwestern Germany. Canadian Mineralogist, 49, 1305–1333.10.3749/canmin.49.5.1305Search in Google Scholar
Göb, S., Guhring, J.E., Bau, M., and Markl, G. (2013) Remobilization of U and REE and the formation of secondary minerals in oxidized U deposits. American Mineralogist, 98, 530–548.10.2138/am.2013.4275Search in Google Scholar
Hofmann, B. (1989) Genese, Alteration und rezentes Fliess- System der Uranlagerstätte Krunkelbach (Menzenschwand, Südschwarzwald), 195 p. Dissertation, Switzerland, Universität Bern.Search in Google Scholar
Hofmann, B., and Eikenberg, J. (1991) The Krunkelbach uranium deposit, Schwarzwald, Germany; correlation of radiometric ages (U-Pb, U-Xe-Kr, K-Ar, 230Th–234U). Economic Geology, 86, 1031–1049.10.2113/gsecongeo.86.5.1031Search in Google Scholar
Janeczek, J., and Ewing, R.C. (1992) Structural formula of uraninite. Journal of Nuclear Materials, 190, 128–132.10.1016/0022-3115(92)90082-VSearch in Google Scholar
Janeczek, J., and Ewing, R.C. (1996) Phosphatian coffinite with rare earth elements and Ce-rich françoisite-(Nd) from sandstone beneath a natural fission reactor at Bangombé, Gabon. Mineralogical Magazine, 60, 665–669.10.1180/minmag.1996.060.401.14Search in Google Scholar
Kohlmann, M., Sowa, H., Reithmayer, K., Schulz, H., Krüger, R.R., and Abriel, W. (1994) Structure of a Y1–x(Gd,Dy,Er)xPO4·2H2O microcrystal using synchrotron radiation. Acta Crystallographica, C50, 1651–1652.Search in Google Scholar
Kolb, U., Gorelik, T., Kübel, C., Otten, M.T., and Hubert, D. (2007) Towards automated diffraction tomography: Part I—Data acquisition. Ultramicroscopy, 107, 507–513.10.1016/j.ultramic.2006.10.007Search in Google Scholar
Kolb, U., Gorelik, T., and Otten, M.T. (2008) Towards automated diffraction tomography. Part II—Cell parameter determination. Ultramicroscopy, 108, 763–772.10.1016/j.ultramic.2007.12.002Search in Google Scholar
Markl, G., and Wolfsried, S. (2011) Das Uran von Menzenschwand, 143 p. München, Christian Weise Verlag.Search in Google Scholar
McLennan, S.M. (1989) Rare earth elements in sedimentary rocks: Influence of provenance and sedimentary processes. Reviews in Mineralogy and Geochemistry, 21, 169–200.10.1515/9781501509032-010Search in Google Scholar
Melkov, V.G., Belova, L.N., Gorshkov, A.I., Ivanova, O.A., Sivtsov, V.A., and Boronnikhin, V.A. (1983) New data on lermontovite. Mineralogiceskij Zhurnal, 5, 82–87.Search in Google Scholar
Merlet, C. (1994) An accurate computer correction program for quantitative electron probe microanalysis. Mikrochimica Acta, 114-115, 363–376.10.1007/BF01244563Search in Google Scholar
Meshik, A.P., Lippolt, H.J., and Dymkov, Y.M. (2000) Xenon geochronology of Schwarzwald pitchblendes. Mineralium Deposita, 35, 190–205.10.1007/s001260050015Search in Google Scholar
Montel, J.-M., Foret, S., Veschambre, M., Nicollet, C., and Provost, A. (1996) Electron microprobe dating of monazite. Chemical Geology, 131, 37–53.10.1016/0009-2541(96)00024-1Search in Google Scholar
Mooney, R.C.L. (1950) X-ray diffraction study of cerous phosphate and related crystals. I. Hexagonal modification. Acta Crystallographica, 3, 337–340.10.1107/S0365110X50000963Search in Google Scholar
Palatinus, L., and Chapuis, G. (2007) SUPERFLIP—A computer program for the solution of crystal structures by charge flipping in arbitrary dimensions. Journal of Applied Crystallography, 40, 786–790.10.1107/S0021889807029238Search in Google Scholar
Palatinus, L., Petříček, V., and Corrêa, C.A. (2015a) Structure refinement using precession electron diffraction tomography and dynamical diffraction: theory and implementation. Acta Crystallographica, A71, 235–244.10.1107/S2053273315001266Search in Google Scholar
Palatinus, L., Corrêa, C.A., Steciuk, G., Jacob, D., Roussel, P., Boullay, P., Kl-ementová, M., Gemmi, M., Kopeček, J., Domeneghetti, M.C., Cámara, F., and Petříček, V. (2015b) Structure refinement using precession electron diffraction tomography and dynamical diffraction: tests on experimental data. Acta Crystallographica, B71, 740–751.10.1107/S2052520615017023Search in Google Scholar
Palatinus, L., Brázda, P., Jelínek, M., Hrdá, J., Steciuk, G., and Klementová, M. (2019) Specifics of the data processing of precession electron diffraction tomography data and their implementation in the program PETS2.0. Acta Crystallographica, B75, 512–522.10.1107/S2052520619007534Search in Google Scholar
Petříček, V., Dušek, M., and Palatinus, L. (2014) Crystallographic Computing System Jana 2006: general features. Zeitschrift Für Kristallographie—Crystalline Materials, 229, 345–352.10.1515/zkri-2014-1737Search in Google Scholar
Pfaff, K., Romer, R.L., and Markl, G. (2009) U–Pb ages of ferberite, chalcedony, agate, ‘U-mica’ and pitchblende: constraints on the mineralization history of the Schwarzwald ore district. European Journal of Mineralogy, 21, 817–836.10.1127/0935-1221/2009/0021-1944Search in Google Scholar
René, M., Dolníček, Z., Sejkora, J., Škácha, P., and Šrein, V. (2019) Uraninite, coffinite and ninöyoite from vein-type uranium deposits of the Bohemian Massif (Central European Variscan Belt). Minerals, 9, 123.10.3390/min9020123Search in Google Scholar
Scharmová, M., and Scharm, B. (1994) Rhabdophane group minerals in the uranium ore district of northern Bohemia (Czech Republic). Journal of the Czech Geological Society, 39, 267.Search in Google Scholar
Škácha, P., Goliáš, V., Sejkora, J., Plášil, J., Strnad, L., Škoda, R., and Ježek, J. (2009) Hydrothermal uranium-base metal mineralization of the Jánská vein, Březové Hory, Příbram, Czech Republic: Lead isotopes and chemical dating of uraninite. Journal of Geosciences, 54, 15–56.10.3190/jgeosci.030Search in Google Scholar
Steciuk, G., Ghazisaeed, S., Kiefer, B., and Plášil, J. (2019) Crystal structure of vyacheslavite, U(PO4)(OH), solved from natural nanocrystal: a precession electron diffraction tomography (PEDT) study and DFT calculations. RSC Advances, 9, 19657–19661.10.1039/C9RA03694FSearch in Google Scholar
Utsunomiya, S., Deditius, A.P., Pointeau, V., and Ewing, R.C. (2008) Coffinite and ningyoite from the natural nuclear reactor at Bangombe, Gabon. Geochimica et Cosmochimica Acta, 72, A968.Search in Google Scholar
Vincent, R., and Midgley, P.A. (1994) Double conical beam-rocking system for measurement of integrated electron diffraction intensities. Ultramicroscopy, 53, 271–282.10.1016/0304-3991(94)90039-6Search in Google Scholar
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