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The crystal structure of rabejacite, the Ca2+-dominant member of the zippeite group

Published online by Cambridge University Press:  05 July 2018

J. Plášil*
Affiliation:
Institute of Physics ASCR, v.v.i., Na Slovance 2, CZ-182 21 Prague 8, Czech Republic
M. Dušek
Affiliation:
Institute of Physics ASCR, v.v.i., Na Slovance 2, CZ-182 21 Prague 8, Czech Republic
J. Čejka
Affiliation:
Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, CZ-193 00 Prague 9, Czech Republic
J. Sejkora
Affiliation:
Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, CZ-193 00 Prague 9, Czech Republic
*

Abstract

The crystal structure of rabejacite from Jáchymov, ideally Ca2[(UO2)4O4(SO4)2](H2O)8, was solved by charge flipping from single-crystal data and refined to R1 = 11.94% for 1422 unique observed reflections [I > 3σ(I)]. According to single-crystal X-ray data, rabejacite is triclinic, space group P, with a = 8.7434(11), b = 8.309(3), c = 8.8693(10) Å , a = 77.86(2), b = 104.635(11), g = 82.935(18)°, V = 598.8(3) A˚ 3 and Z = 1, with Dcalc = 4.325 g cm–3. The structure refinement proved that rabejacite is related to the zippeite group of minerals, as it is based upon the structural sheets of the zippeite topology of composition [(UO2)4O4(SO4)2]4–. Located in the interlayer between the sheets, which are stacked perpendicular to [010], are Ca2+ cations and H2O groups. Ca2+ ions are [7]-coordinated, by three uranyl O atoms from adjacent sheets and four H2O groups. An additional H2O group, which is not bonded directly to any cation, is located in the interlayer. Along with rabejacite, its Cu-rich variety was found in the specimens examined and characterized structurally. Its crystal structure (R1 = 10.15% for 1049 reflections with I > 3s(I)) is practically the same as that of rabejacite, but there is an additional Cu2+ site located in between pairs of Ca polyhedra. The structural formula is (Ca1.56Cu0.40)Σ1.90[(UO2)4O4(SO4)2](H2O)8, Z = 1. Its existence suggests a greater diversity in zippeite crystal chemistry than was thought previously and also the possibility of a new Cu2+-dominant zippeite mineral besides pseudojohannite.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2014

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References

Agilent Technologies (2012) CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, UK.Google Scholar
Bergerhoff, G., Berndt, M., Brandenburg, K. and Degen, T. (1998) Concerning inorganic crystal structure types. Acta Crystallographica, B55, 147156.Google Scholar
Brown, I.D., (1981) The bond-valence method: an empirical approach to chemical structure and bonding. Pp. 130 in: Structure and Bonding in Crystals (M. O’Keeffe and A. Navrotsky, editors). Vol. 2. Academic Press, New York, USA.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., (2009) Recent developments in the methods and applications of the bond valence model. Chemical Reviews, 109, 68586919.CrossRefGoogle ScholarPubMed
Brown, I.D., and Altermatt, D. (1985) Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Acta Crystallographica, B41, 244248.CrossRefGoogle Scholar
Brugger, J., Meisser, N. and Burns, P.C., (2003) Contribution to the mineralogy of acid drainage of uranium minerals: marecottite and the zippeitegroup. American Mineralogist, 88, 676685.CrossRefGoogle Scholar
Brugger, J., Wallwork, K.S., Meisser, N., Pring, A., Ondruš, P. and Čejka, J. (2006) Pseudojohannite from Jáchymov, Musunoï and La Creusaz: a new member of the zippeite group. American Mineralogist, 91, 929936.CrossRefGoogle Scholar
Burns, P.C., (2005) U6+ minerals and inorganic compounds: insights into an expanded structural hierarchy of crystal structures. The Canadian Mineralogist, 43, 18391894.CrossRefGoogle Scholar
Burns, P.C., and Hawthorne, F.C., (1995) Coordination geometry structural pathways in Cu2+ oxysalt minerals. The Canadian Mineralogist, 33, 889905.Google Scholar
Burns, P.C., Ewing, R.C., and Hawthorne, F.C., (1997) The crystal chemistry of hexavalent uranium: polyhedron geometries, bond-valence parameters, and polymerization of polyhedra. The Canadian Mineralogist, 35, 15511570.Google Scholar
Burns, P.C., Deely, K.M., and Hayden, L.A., (2003) The crystal chemistry of the zippeite group. The Canadian Mineralogist, 41, 687706.CrossRefGoogle Scholar
Clark, R.C., and Reid, J.S., (1995) The analytical calculation of absorption in multifaceted crystals. Acta Crystallographica, A51, 887897.CrossRefGoogle Scholar
Deliens, M. and Piret, P. (1993) La rabejacite, Ca(UO2)4 (SO4)2(OH)6·6H2O, nouveau sulphate d’uranyle et de calcium des gıˆtes du Lode`vois, Hérault, France. European Journal of Mineralogy, 5, 873877.CrossRefGoogle Scholar
Frondel, C., Ito, J., Honea, R.M., and Weeks, A.M., (1976) Mineralogy of the zippeite group. The Canadian Mineralogist, 14, 429436.Google Scholar
Frost, R.L., Čejka, J., Bostrom, T., Weier, M. and Martens, W. (2007) Raman spectroscopic study of the molecular structure of the uranyl mineral zippeite from Jáchymov (Joachimsthal), Czech Republic. Spectrochimica Acta, A67, 12201227.CrossRefGoogle Scholar
Hawthorne, F.C., (2012) A bond-topological approach to theoretical mineralogy: crystal structure, chemical composition and chemical reactions. Physics and Chemistry of Minerals, 39, 841874.CrossRefGoogle Scholar
Hawthorne, F.C., and Schindler, M. (2008) Understanding the weakly bonded constituents in oxysalt minerals. Zeitschrift für Kristallographie, 223, 4168.Google Scholar
Krivovichev, S.V., and Plášil, J. (2013) Mineralogy and crystallography of uranium. Pp. 15119 in: Uranium, from Cradle to Grave (P.C. Burns and G.E. Sigmon, editors). Mineralogical Association of Canada Short Course, 43. Mineralogical Association of Canada, Québec, Canada.Google Scholar
Locock, A.J., (2007) Trends in actinide compounds with the autunite sheet-anion topology. Proceedings of the Russian Mineralogical Society, 123(7), 115137.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, 451456.CrossRefGoogle Scholar
Palatinus, L. and van der Lee, A. (2008) Symmetry determination following structure solution in P1. Journal of Applied Crystallography, 41, 975984.CrossRefGoogle Scholar
Peeters, M.O., Vochten, R. and Blaton, N. (2008) The crystal structures of synthetic potassium-transitionmetal zippeite-group phases. The Canadian Mineralogist, 46, 173182.CrossRefGoogle Scholar
Petříček, V., Dušek, M. and Palatinus, L. (2006) Jana2006. The Crystallographic Computing System. Institute of Physics, Prague.Google Scholar
Petříček, V., Dušek, M. and Palatinus, L. (2014) Crystallographic computing system Jana 2006: general features. Zeitschrift für Kristallographie, 229, 345352.Google Scholar
Plášil, J., Buixaderas, E., Čejka, J., Sejkora, J., Jehlička, J. and Novák, M. (2010) Raman spectroscopic study of the uranyl sulphate mineral zippeite: low wavenumber and U–O stretching regions. Analytical and Bioanalytical Chemisty, 397, 27032715.CrossRefGoogle ScholarPubMed
Plášil, J., Dušek, M., Novák, M., Čejka, J., Císařová, I. and Škoda, R. (2011a) Sejkoraite-(Y), a new member of the zippeite group containing trivalent cations from Jáchymov (St. Joachimsthal), Czech Republic: description and crystal structure refinement. American Mineralogist, 96, 983991.CrossRefGoogle Scholar
Plášil, J., Mills, S.J., Fejfarová, K., Dušek, M., Novák, M., Škoda, R., Čejka, J. and Sejkora, J. (2011b) The crystal structure of natural zippeite, K1.85H+ 0.15 [(UO2)4O2(SO4)2(OH)2](H2O)4, from Jáchymov, Czech Republic. The Canadian Mineralogist, 49, 10891103.CrossRefGoogle Scholar
Plášil, J., Fejfarová, K., Wallwork, K.S., Dušek, M., Škoda, R., Sejkora, J., Čejka, J., Veselovský , F., Hloušek, J., Meisser, N. and Brugger, J. (2012) Crystal structure of pseudojohannite, with a revised formula, Cu3(OH)2[(UO2)4O4(SO4)2](H2O)12 . American Mineralogist, 97, 17961803.CrossRefGoogle Scholar
Plášil, J., Fejfarová, K., Škoda, R., Dušek, M., Čejka, J. and Marty, J. (2013) The crystal structure of magnesiozippeite, Mg[(UO2)2O2(SO4)](H2O)3.5, from East Saddle Mine, San Juan County, Utah (U.S.A.). Mineralogy and Petrology, 107, 211219.CrossRefGoogle Scholar
Plášil, J., Sejkora, J., Škoda, R. and Škácha, P. (2014) The recent weathering of uraninite from the Č ervená vein, Jáchymov (Czech Republic): a fingerprint of the primary mineralization geochemistry onto the alteration association. Journal of Geosciences, 59, 223253.CrossRefGoogle Scholar
Schindler, M. and Hawthorne, F.C., (2008) The stereochemistry and chemical composition of interstitial complexes in uranyl-oxysalt minerals. The Canadian Mineralogist, 46, 467501.CrossRefGoogle Scholar
Sejkora, J., Čejka, J. and Ondruš, P. (2000) New data of rabejacite (Jáchymov, the Krušné hory Mts., Czech Republic). Neues Jahrbuch für Mineralogie, Monatshefte, 2000, 289301.Google Scholar
Tasci, E.S., de la Flor, G., Orobengoa, D., Capillas, C., Pérez-Mato, J.M., and Aroyo, M.I., (2012) An introduction to the tools hosted in the Bilbao Crystallographic Server. EPJ Web of Conferences, 22, 00009, DOI:10.1051/epjconf/20122200009.CrossRefGoogle Scholar
Wylie, E.M., and Burns, P.C., (2012) Crystal structures of six new uranyl selenite and selenite compounds and their relationship with uranyl mineral structures. The Canadian Mineralogist, 50, 147157.CrossRefGoogle Scholar
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