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Štěpite, U(AsO3OH)2·4H2O, from Jáchymov, Czech Republic: the first natural arsenate of tetravalent uranium

Published online by Cambridge University Press:  05 July 2018

J. Plášil ,
K. Fejfarová ,
J. Hloušek ,
R. Škoda ,
M. Novák ,
J. Sejkora ,
J. Čejka ,
M. Dušek ,
F. Veselovský  and
P. Ondruš
...Show all authors
J. Plášil*
Affiliation:
Institute of Physics ASCR, v.v.i., Na Slovance 2, Prague 8, 182 21, Czech Republic
K. Fejfarová
Affiliation:
Institute of Physics ASCR, v.v.i., Na Slovance 2, Prague 8, 182 21, Czech Republic
J. Hloušek
Affiliation:
U Roháčových kasáren 24, CZ-100 00, Prague 10, Czech Republic
R. Škoda
Affiliation:
Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37, Brno, Czech Republic
M. Novák
Affiliation:
Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37, Brno, Czech Republic
J. Sejkora
Affiliation:
Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, CZ-193 00, Prague 9, Czech Republic
J. Čejka
Affiliation:
Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, CZ-193 00, Prague 9, Czech Republic
M. Dušek
Affiliation:
Institute of Physics ASCR, v.v.i., Na Slovance 2, Prague 8, 182 21, Czech Republic
F. Veselovský
Affiliation:
Czech Geological Survey, Geologická 6, CZ-152 00, Praha 5, Czech Republic
P. Ondruš
Affiliation:
Biskupský dvůr 2, CZ-110 00, Prague 1, Czech Republic
J. Majzlan
Affiliation:
Institute of Geosciences, Friedrich-Schiller University, Burgweg 11, D-07749 Jena, Germany
*
* E-mail: [email protected]
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Abstract

Štěpite, tetragonal U(AsO3 OH)2(H2O)4 (IMA 2012-006), is the first natural arsenate of tetravalent uranium. It occurs in the Geschieber vein, Jáchymov ore district, Western Bohemia, Czech Republic, as emerald-green crystalline crusts on altered arsenic. Associated minerals include arsenolite, běhounekite, claudetite, gypsum, kaatialaite, the new mineral vysokýite (IMA 2012-067) and a partially characterized phase with the formula (H3O)+2(UO2)2(AsO4)2˙6H2O. Štěpite typically forms tabular crystals with prominent {001} and {010} faces, up to 0.6 mm in size. The crystals have a vitreous lustre and a grey to greenish grey streak. They are brittle with an uneven fracture and a very good cleavage on (001). Their Mohs hardness is about 2. Štěpite is not fluorescent in either short-wave or long-wave ultraviolet light. It is biaxial (–) with refractive indices (at 590 nm) of α = 1.636(2), β = 1.667(3), γ = 1.672(2) and 2Vobs < ~5°, anomalous greyish to pale yellow interference colours, and no pleochroism. The composition is as follows: 0.12Na2O, 50.19 UO2, 0.04SiO4, 0.09 P2O5, 0.93 As2O5, 1.95 SO3, 16.41 H2O; total 107.90 wt.%, yielding an empirical formula (based on 12 O a. p. f. u.) of (U1.01Na0.02)Σ1.03[(AsO3OH)1.82 (PO3OH)0.04(SO4)0.13(SiO4)0.01]Σ 2.00˙4H2O. Štěpite is tetragonal, crystallizing in space group I41/acd, with a = 10.9894(1), c = 32.9109(6) Å, V = 3974.5(1) Å3, Z = 16 and Dcalc = 3.90 g cm-3. The six strongest peaks in the X-ray powder-diffraction pattern [dobs in Å (I) (hkl)] are as follows: 8.190(100)(004), 7.008(43)(112), 5.475(18)(200), 4.111(16)(008), 3.395(20)(312,217), 2.1543(25)(419). The crystal structure of šteěpite has been solved from singlecrystal X-ray diffraction data by the charge-flipping method and refined to R1 = 0.0353 based on 1434 unique observed reflections, and to wR2 = 0.1488 for all 1523 unique reflections. The crystal structure of štšpite consists of sheets perpendicular to [001], made up of eight-coordinate uranium atoms and hydroxyarsenate 'tetrahedra'. The ligands surrounding the uranium atom consist of six oxygen atoms which belong to the hydroxyarsenate groups and two oxygen atoms which belong to interlayer H2 O molecules. Each UO8 polyhedron is connected to five other U polyhedra via six AsO3OH groups. Adjacent electroneutral sheets, of composition [U4+(AsO3OH)22-]0, are linked by hydrogen bonds involving H2 O molecules in the interlayers and OH groups in the sheets. The new mineral is named in honour of Josef Štěp (1863–1926), a Czech mining engineer and 'father' of the world's first radioactive spa at Jáchymov.

Keywords

štěpitenew mineraluranium(IV) bis(hydrogenarsenate) tetrahydratecrystal structurechemical compositionoxidation zoneJáchymovCzech Republic
Type
Letter
Information
Mineralogical Magazine , Volume 77 , Issue 1 , February 2013 , pp. 137 - 152
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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Footnotes

†

Zdeněk Mrázek (15th February 1952–15th April 1984) was a well known Czech chemical mineralogist who worked at the Institute of Chemical Technology in Prague. Zdeněk was the first person to investigate štěpite, more than 30 years ago. He attempted to synthesize U(AsO3OH)2(H2O)4 with the aim of comparing the natural and synthetic phases. This research was terminated by his tragic and untimely death. The mineral mrázekite was named in his honour (Řídkošil et al., 1992; Effenberger et al., 1994).

References

Becker, P.J. and Coppens, P. (1974) Extinction within the limit of validity of the Darwin transfer equations. I. General formalism for primary and secondary extinction and their applications to spherical crystals. Acta Crystallographica, A30, 129–147.CrossRefGoogle 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 Vsesoyuznego Mineralogicheskego Obshchestva, 113, 360–365. [in Russian].Google Scholar
Brandenburg, K. and Putz, H. (2005) DIAMOND Version 3. Crystal Impact GbR, Postfach 1251, D- 53002 Bonn, Germany.Google Scholar
Brese, N.E. and O’Keeffe, M. (1991) Bond-valence parameters for solids. Acta Crystallographica, B47, 192–197.CrossRefGoogle Scholar
Brown, I.D. (1981) The bond-valence method: an empirical approach to chemical structure and bonding. Pp. 1–30. in: Structure and Bonding in Crystals II (M. O’Keeffe and A. Navrotsky, editors). Academic Press, New York.Google Scholar
Brown, I.D. (2002) The Chemical Bond in Inorganic Chemistry. The Bond Valence Model. Oxford University Press, Oxford, UK.Google Scholar
Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Acta Crystallographica, B41, 244–248.CrossRefGoogle Scholar
Burns, P.C., Finch, R.J., Hawthorne, F.C., Miller, M.L. and Ewing, R.C. (1997) The crystal structure of ianthinite, [U4+(UO2)4.6(OH)4(H2O)4](H2O)5: a possible phase for Pu4+ incorporation during the oxidation of spent nuclear fuel. Journal of Nuclear Materials, 249, 199–206.CrossRefGoogle Scholar
Chernorukov, N.G., Korshunov, I.A. and Voinova L.I. (1985) New uranium compounds. U(HAsO4)2.4H2O. Radiokhimiya, 27, 676–679.Google Scholar
Clark, R.C. and Reid, J.S. (1995) The analytical calculation of absorption in multifaceted crystals. Acta Crystallographica, A51, 887–897.CrossRefGoogle Scholar
Dardenne, K., Brendebach, B., Denecke, M.A., Liu, X., Rothe, J. and Vitova, T. (2009) New developments at the INE-beamline for actinide research at ANKA. Journal of Physics: Conference Series, 190, http:// dx.doi.org/10.1088/1742-6596/190/1/012037.Google Scholar
Effenberger, H., Krause, W., Belendorff, K., Bernhardt, H.J., Medenbach, O., Hybler, J. and Petříček, V. (1994) Revision of the crystal structure of mrázekite, Bi2Cu3(OH)2.2(PO4)2.2H2O. The Canadian Mineralogist, 32, 365–372.Google Scholar
Finch, R. and Murakami, T. (1999) Systematics and paragenesis of uranium minerals. Pp. 91–179. in: Uranium: Mineralogy, Geochemistry and the Environment (P.C. Burns and R.C. Ewing editors). Reviews in Mineralogy, 38. Mineralogical Society of America, Washington DC.Google Scholar
Holland, T. and Redfern, S.A.T. (1997) Unit cell refinement from powder diffraction data: the use of regression diagnostics. Mineralogical Magazine, 61, 65–77.CrossRefGoogle Scholar
Keller, P. (1971) Die Kristallchemie der Phosphat- und Arsenatminerale unter besonderer Berücksichtigung der Kationen-Koordinationspolyeder und des Kristallwassers. Teil I: Die Anionen der Phosphatund Arsenatminerale. Neues Jahrbuch fü r Mineralogie, Monatshefte, 1971, 491–510.Google Scholar
Kierkegaard, P. (1956) The crystal structure of U(SO4)2(H2O)4 . Acta Chemica Scandinavica, 10, 599–616.CrossRefGoogle Scholar
Krivovichev, S.V. and Burns, P.C. (2004) g-UMo2O8 as a new polymorph of uranium dimolybdate containing tetravalent uranium. Doklady Physics, 49, 76–77.CrossRefGoogle Scholar
Langmuir, D. (1978) Uranium solution-mineral equilibria at low temperatures with applications to sedimentary ore deposits. Geochimica et Cosmochimica Acta, 42, 547–569.CrossRefGoogle Scholar
Libowitzky, E. (1999) Correlation of O–H stretching frequencies and O–H···O hydrogen bond lengths in minerals. Monatshefte für Chemie, 130, 1047–1059.CrossRefGoogle Scholar
Mache, H. and Meyer, S. (1905) U¨ ber die Radioaktivität der Quellen der böhmischen Bädergruppe: Karlsbad, Marienbad, Teplitz-Schönau-Dux, Franzensbad sowie von St Joachimsthal. Sitzungsberichten der kaiserliche Akademie der Wissenschaften in Wien. Mathematisch - naturwissenschaftliche Klasse, 114, 1–30.Google Scholar
Mandarino, J.A. (1981) The Gladstone–Dale relationship: part IV. The compatibility concept and its application. The Canadian Mineralogist, 19, 441–450.Google Scholar
Melkov, V.G., Belova, L.N., Gorshkov, A.I., Ivanova, O.A., Sivtsov, A.V. and Boronikhin V.A. (1983) New data on lermontovite. Mineralogicheskii Zhurnal, 5, 82–87. [in Russian].Google Scholar
Mielke, Z. and Ratajczak, H. (1972) The force constants and vibrational frequencies of orthoarsenates. Bulletin de l’Académie Polonaise des Sciences, Série des Sciences Chimiques, 20, 265–270.Google Scholar
Momma, K. and Izumi, F. (2008) VESTA: a threedimensional visualization system for electronic and structural analysis. Journal of Applied Crystallography, 41, 653–658.CrossRefGoogle Scholar
Muto, T., Meyrowitz, R., Pommer, A.R. and Murano, T. (1959) Ningyoite, a new uranous phosphate mineral from Japan. American Mineralogist, 44, 633–650.Google Scholar
Ondruš, P., Veselovský, F., Skála, R., Císařová, I., Hloušek, J., Frýda, J., Vavřín, I., Č ejka, J. and Gabašová, A. (1997) New naturally occurring phases of secondary origin from Jáchymov (Joachimsthal). Journal of the Czech Geological Society, 42, 77–108.Google Scholar
Ondruš, P., Veselovský, F., Gabašová, A., Hloušek, J., Šrein, V., Vavřín, I., Skála, R., Sejkora, J. and Drábek, M. (2003) Primary minerals of the Jáchymov ore district. Journal of the Czech Geological Society, 48, 19–147.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, 451–456.CrossRefGoogle Scholar
Petříček, V., Dušek, M. and Palatinus, L. (2006) JANA2006. The Crystallographic Computing System. Institute of Physics, Prague.Google Scholar
Plášil, J., Fejfarová, K., Novák, M., Dušek, M., Škoda, R., Hloušek, J., Č ejka, J., Majzlan, J., Sejkora, J., Machovič, V. and Talla, D. (2011) Běhounekite, U(SO4)2(H2O)4, from Jáchymov (St Joachimsthal), Czech Republic: the first natural U4+ sulphate. Mineralogical Magazine, 75, 2739–2753.CrossRefGoogle Scholar
Pouchou, J.L. and Pichoir, F. (1985) “PAP” (j rZ) procedure for improved quantitative microanalysis. Pp. 104–106. in: Microbeam Analysis (J.T. Armstrong, editor). San Francisco Press, San Francisco, California, USA.Google Scholar
Ravel, B. and Newville, M. (2005) ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. Journal of Synchrotron Radiation, 12, 537–541.CrossRefGoogle ScholarPubMed
Řídkošil, T., Šrein, V., Fábry, J., Hybler, J. and Maximov, B.A. (1992) Mrázekite , Bi2Cu3(OH)2.2(PO4)2.2H2O, a new mineral species and its crystal structure. The Canadian Mineralogist, 30, 215–224.Google Scholar
Skvortsova, K.V. and Sidorenko, G.A. (1965) Sedovite, a new supergene mineral of uranium and molybdenum. Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva, 94, 548–554. [in Russian].Google Scholar
Smith, D.G.W. and Nickel, E.H. (2007) A system for codification for unnamed minerals: report of the Subcommittee for Unnamed Minerals of the IMA Commission on New Minerals, Nomenclature and Classification. The Canadian Mineralogist, 45, 983–1055.CrossRefGoogle Scholar
Štep, J. and Becke, F. (1904) Das Vorkommen des Uranpecherz zu St. Joachimsthal. Sitzungsberichten der kaiserliche Akademie der Wissenschaften in Wien. Mathematisch - naturwissenschaftliche Klasse, 113, 1–34.Google Scholar
Tvrdý, J. and Plášil|J. (2010) Jáchymov – Reiche Erzlagerstä tte und Radonbad im böhmischen Westerzgebirge. Aufschluss, 61, 277–292.Google Scholar
Vansant, F. K., van der Veken, B.J. and Desseyn, H.O. (1973) Vibrational analysis of arsenic acid and its anions. I. Description of the Raman spectra. Journal of Molecular Structure, 15, 425–437.CrossRefGoogle Scholar
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