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Leydetite, Fe(UO2)(SO4)2(H2O)11, a new uranyl sulfate mineral from Mas d’Alary, Lodève, France

  • J. Plášil (a1), A. V. Kasatkin (a2), R. Škoda (a3), M. Novák (a3), A. Kallistová (a4), M. Dušek (a1), R. Skála (a4), K. Fejfarová (a1), J. Čejka (a5), N. Meisser (a6), H. Goethals (a7), V. Machovič (a8) (a9) and L. Lapčák (a8)...


Leydetite, monoclinic Fe(UO2)(SO4)2(H2O)11(IMA 2012–065), is a new supergene uranyl sulfate from Mas d'Alary, Lodève, Hérault, France. It forms yellow to greenish, tabular, transparent to translucent crystals up to 2 mm in size. Crystals have a vitreous lustre. Leydetite has a perfect cleavage on (001). The streak is yellowish white. Mohs hardness is ∼2. The mineral does not fluoresce under long- or short-wavelength UV radiation. Leydetite is colourless in transmitted light, non-pleochroic, biaxial, with α = 1.513(2), γ = 1.522(2) (further optical properties could not be measured). The measured chemical composition of leydetite, FeO 9.28, MgO 0.37, Al2O30.26, CuO 0.14, UO340.19, SO321.91, SiO20.18, H2O 27.67, total 100 wt.%, leads to the empirical formula (based on 21 O a.p.f.u.), (Fe0.93Mg0.07Al0.04Cu0.01)Σ1.05(U1.01O2)(S1.96Si0.02)Σ1.98O8(H2O)11. Leydetite is monoclinic, space group C2/c, with a = 11.3203(3), b = 7.7293(2), c = 21.8145(8) Å, β = 102.402(3)°, V = 1864.18(10) Å3, Z = 4, and Dcalc = 2.55 g cm–3. The six strongest reflections in the X-ray powder diffraction pattern are [d obs in Å (I) (hkl)]: 10.625 (100) (002), 6.277 (1) (11), 5.321 (66) (004), 3.549 (5) (006), 2.663 (4) (008), 2.131 (2) (0 0 10). The crystal structure has been refined from single-crystal X-ray diffraction data to R 1 = 0.0224 for 5211 observed reflections with [I > 3σ(I)]. Leydetite possesses a sheet structure based upon the protasite anion topology. The sheet consists of UO7 bipyramids, which share four of their equatorial vertices with SO4 tetrahedra. Each SO4 tetrahedron, in turn, shares two of its vertices with UO7 bipyramids. The remaining unshared equatorial vertex of the bipyramid is occupied by H2O, which extends hydrogen bonds within the sheet to one of a free vertex of the SO4 tetrahedron. Sheets are stacked perpendicular to the c direction. In the interlayer, Fe2+ ions and H2O groups link to the sheets on either side via a network of hydrogen bonds. Leydetite is isostructural with the synthetic compound Mg(UO2)(SO4)2(H2O)11. The name of the new mineral honours Jean Claude Leydet (born 1961), an amateur mineralogist from Brest (France), who discovered the new mineral.


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Agilent Technologies (2012) CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, Oxfordshire, UK.
Alcock, N.W., Roberts, M.M. and Brown, D. (1982) Actinide structural studies. Part 3. The crystal and molecular structures of UO2SO4·H2SO4·5H2O and 2NpO2SO4·H2SO4·4H2O. Journal of the Chemical Society, Dalton Transactions, 869–873.
Bartlett, J.R. and Cooney, R.P. (1989) On the determination of uranium-oxygen bond lengths in dioxouranium(VI) compounds by Raman spectroscopy. Journal of Molecular Structure, 193, 295–300.
Bavoux, B. and Guiollard, P.-C. (1999) L’uranium du Lodévois (Hérault)L’uranium du Lodévois (Hérault). Saint-Pourcain, Sioule.
Boisson, J.-M. and Leydet, J.-C. (1998a) L’uranium et ses descendants. La Radioactivité . Le Régne Minéral, hors série IV, 13–36.
Boisson, J.-M. and Leydet, J.-C. (1998b) Les minéraux uranifères français. La Radioactivité. Le Régne Minéral, hors série IV, 37–60.
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, USA.
Brown, I.D. (2002) The Chemical Bond in Inorganic Chemistry: The Bond Valence Model. Oxford University Press, UK.
Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Acta Crystallographica, B41, 244–247. with updated parameters from web-mirrors/i_d_brown/.
Burns, P.C. (2005) U6+ minerals and inorganic compounds: insights into an expanded structural hierarchy of crystal structures. The Canadian Mineralogist, 43, 1839–1894.
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, 1551–1570.
Čejka, J. (1999) Infrared spectroscopy and thermal analysis of the uranyl minerals. Pp. 521–622. in: Uranium: Mineralogy, Geochemistry and the Environment (P.C. Burns and R. Finch, editors). Reviews in Mineralogy, 38, Mineralogical Society of America, Washington DC.
Čejka, J. (2004) Vibrational spectroscopy of uranyl minerals – infrared and Raman spectra of uranyl minerals. I. Uranyl, UO2 2+. Bulletin mineralogickopetrologického Oddělení Národního Muzea (Praha), 12, 44–51. (in Czech).
Čejka, J. (2007) Vibrational spectra of uranyl minerals – infrared and Raman spectra of uranyl minerals. III. Uranyl sulphates. Bulletin mineralogicko-petrologického Oddělení Národního Muzea (Praha), 14–15. 40–46. (in Czech).
Cheary, R.W. and Coelho, A.A. (1997) XFIT and FOURYA. CCP14 Powder Diffraction Library, Engineering and Physical Sciences Research Council, Daresbury Laboratory, Warrington, UK (
Clark, R.C. and Reid, J.S. (1995) The analytical calculation of absorption in multifaceted crystals. Acta Crystallographica, A51, 887–897.
Deliens, M., Henriot, O., Mathis, V. and Caubel, A. (1990) Minéraux des gisements d’uranium du Lodévois. Association françaised e Microminéralogie, Paris.
Henriot, O. and Leydet, J.-C. (1998) Le gisement de Mas d’Alary Village, Hérault, France. Le cahier des Micromonteurs, 2, 13–26.
Kraus, W. and Nolze, G. (1996) POWDER CELL – a program for the representation and manipulation of crystal structures and calculation of the resulting X-ray powder patterns. Journal of Applied Crystallography, 29, 301–303.
Lancelot, J., Briqueu, L., Respaut, J.-P. and Clauer, N. (1995) Géochimie isotopique des systèmes U-Pb/ Pb-Pb et évolution polyphasée des gîtes d’uranium du Lodévois et du sud du Massif central. Chronique de la Recherche Minière, 521, 3–18.
Lane, M.D. (2007) Mid-infrared emission spectroscopy of sulphate and sulphate-bearing minerals. American Mineralogist, 92, 1–18.
Laugier, J. and Bochu, B. (2003) CELREF: Unit Cell Refinement Program from Powder Diffraction Diagram. Laboratoires des Matériaux et du Génie Physique, Ecole Nationale Supérieure de Physique de Grenoble (INPG), Grenoble, France.
Leydet, J.-C. (2006) Shinkolobwe, République Démocratique du Congo-cahier spécial: minéraux dédiés à des minéralogistes français ou à des localités françaises. Le cahier des Micromonteurs, 10, 86–88.
Libowitzky, E. (1999) Correlation of O-H stretching frequencies and O–H_O hydrogen bond lengths in minerals. Monatshefte für Chemie, 130, 1047–1059.
Ling, J., Sigmon, G.E., Ward, M., Roback, N. and Burns, P.C. (2010) Syntheses, structures, and IR spectroscopic characterization of new uranyl sulphate/ selenate 1D-chain, 2D-sheet and 3D-framework. Zeitschrift für Kristallographie, 225, 230–239.
Majzlan, J., Alpers, C.N., Koch, C.B., McCleskey, R.B., Myneni, S.C.B. and Neil, J.M. (2011) Vibrational, X-ray absorption, and Mössbauer spectra of sulfate minerals from the weathered massive sulfide deposit at Iron Mountain, California. Chemical Geology, 284, 296–305.
Mandarino, J.A. (1981) The Gladstone-Dale relationship. IV. The compatibility concept and its application. The Canadian Mineralogist, 19, 441–450.
Nakamoto, K. (1986) Infrared and Raman Spectra of Inorganic and Coordination Compounds. J. Wiley and Sons, New York.
Niinistö, L., Toivonen, J. and Valkonen, J. (1979) Uranyl (VI) compounds. II. The crystal structure of potassiumur any lsulphated i hydrate K2UO2(SO4)2·2H2O. Acta Chemica Scandinavica, A33, 621–624.
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.
Petříček, V., Dušek, M. and Palatinus, L. (2006) Jana2006. The crystallographic computing system. Institute of Physics, Prague, Czech Republic.
Plášil, J., Hauser, J., Petříček, V., Meisser, N., Mills, S.J., Škoda, R., Fejfarová, K., Čejka, J., Sejkora, J., Hloušek, J., Johannet, J.-M., Machovič, V. and Lapčák. L. (2012a) Crystal structure and formula revision of deliensi t e , Fe[(UO2 ) 2(SO4 ) 2 (OH)2](H2O)7 . Mineralogical Magazine, 76, 2837–2860.
Plášil, J., Hloušek, J., Veselovský, F., Fejfarová, K., Dušek, M., Škoda, R., Novák, M., Čejka, J., Sejkora, J. and Ondruš, P. (2012b) Adolfpateraite, K(UO2)(SO4)(OH)(H2O), a new uranyl sulphate mineral from Jáchymov, Czech Republic. American Mineralogist, 97, 447–454.
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.
Schindler, M. and Hawthorne, F.C. (2008) The stereochemistry and chemical composition of interstitial complexes in uranyl-oxysalt minerals. The Canadian Mineralogist, 46, 467–501.
Serezhkin, V.N., Soldatkina, M.A. and Efremov, V.A. (1981) Crystal structure of Mg(UO2)(SO4)2·11H2O. Journal of Structural Chemistry, 22, 454–457.
Vochten, R., Blaton, N. and Peeters, O. (1997) Deliensite, Fe(UO2)2(SO4)2(OH)2·3H2O, a new ferrous uranyl sulphate hydroxy hydrate from Mas d’Alary, Lodève, Hérault, France. The Canadian Mineralogist, 35, 1021–1025.
Volod’ko, L.V., Komyak, A.I. and Sleptsov, L.I. (1965) Infrared absorption spectrum of the sodium uranyl acetate single crystal. Zhurnal Prikladnoi Spektroskopii, 3, 65–71.
Volod’ko, L.V., Komyak, A.I. and Umreyko, D.S. (1981) Uranyl Compounds, Spectra and Structure, vol. 1. Izdatelsvo BGU Minsk (in Russian).



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