Bulletin Mineralogie Petrologie

Škácha Pavel, Plášil Jakub, Sejkora Jiří, Čejka Jiří, Škoda Radek, Meisser Nicolas

Ročník 22, číslo 2 (2014), strana 240-248

bayleyite, uranyl carbonate, crystal structure, electron microprobe data, Raman spectroscopy, Jáchymov

A rare supergene uranyl carbonate mineral, bayleyite, was found on a single specimen originated from the 3rd level of the Barbora shaft, the Jáchymov ore district, Czech Republic. Bayleyite occurs there as a yellow very small, imperfect crystals of glassy lustre forming crystalline aggregates up to 3 mm on a small fragment of the rock. Liebigite, schröckingerite, rabbittite and natrozippeite were found in the mineral association. According to single-crystal X-ray data bayleyite is monoclinic, space group P2₁/a, with a = 26.535(1), b = 15.244(2), c = 6.497(3) Å, β = 92.942(10), and V = 2624.5(13) ų. Crystal structure was refined to R₁ = 2.68% on the basis of 5008 unique observed reflections [I_obs.>3σ(I)] collected on a Oxford Diffraction Gemini diffractometer with a Atlas CCD detector and MoKα radiation. Chemical analyses of bayleyite yielded the average composition MgO 12.68, FeO 0.06, Al₂O₃ 0.05, SiO₂ 0.45, UO₃ 51.97, CO_2calc. 21.27, H₂O_calc. 29.46, total 115.94 wt. % corresponding to the empirical formula (Mg_1.73 Al_0.01Fe_0.01)_Σ1.75(UO₂)_1.00[(CO₃)_2.66(SiO₄)_0.04] •18H₂O calculated on the basis of U = 1 apfu (CO₃ content derived from the charge-balance). Raman spectrum of bayleyite is dominated by the symmetric stretching vibration of UO₂²⁺ ion, and stretching and bending modes of planar CO₃ groups. Inferred uranyl bond-lenghts and possible hydrogen bond lenghts obtained from the Raman frequencies of corresponding vibrations, based on the empirical relations, are consistent with values from the refined structure.

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Amayri S. (2002) Synthese, Charakterisierung und Löslichkeit von Erdalkaliuranylcarbonaten M₂[UO₂(CO₃)₃].xH₂O; M = Mg, Ca, Sr, Ba. Doktorská disertační práce, Fakultät Mathematik und Naturwissenschaften der Technischen Universität Dresden.

Amayri S., Reich T., Arnold T., Geipel G., Bernhard G. (2005) Spectroscopic characterization of alkaline earth uranyl carbonates. J. Solid State Chem. 178, 567-577.

Anderson A., Cheih Ch., Irish D. E., Tong J. P. K. (1980) An X-ray crystallographic, Raman, and infrared spectral study of crystalline potassium uranyl carbonate, K₄UO₂(CO₃)₃. Can. J. Chem. 58, 1651-1658.

Axelrod J. M., Grimaldi F. S., Milton C., Murata K. J. (1951) The uranium minerals from the Hillside mine, Yavapai County, Arizona. Am. Mineral. 36, 1-22.

Bartlett J. R., Cooney R. P. (1989) On the determination of uranium-oxygen bond lengths in dioxouranium(VI) compounds by Raman spectroscopy. J. Mol. Struct. 193, 295-300.

Brugger J., Meisser N., Burns P. C. (2003) Contribution to the mineralogy of acid drainage of uranium minerals: marecottite and the zippeite-group. Am. Mineral. 88, 676-685.

Burns P. C. (1999) The crystal chemistry of uranium. Rev. Mineral. 38, 23-90.

Burns P. C. (2005) U⁶⁺ minerals and inorganic compounds: Insights into an expanded structural hierarchy of crystal structures. Can. Mineral. 43, 1839-1894.

Clark R. C., Reid J. S. (1995) The analytical calculation of absorption in multifaceted crystals. Acta Cryst. A51, 887-897.

Čejka J. (1999) Infrared spectroscopy and thermal analysis of the uranyl minerals. Rev. Mineral. 38, 521-622.

Čejka J. (2004) Vibrační spektroskopie minerálů uranylu – infračervená a Ramanovská spektra minerálů uranylu I. Uranyl, UO₂²⁺. Bull. mineral.-petrolog. odd. Nár. muz. (Praha) 12, 44-51.

Čejka J. (2005) Vibrační spektroskopie minerálů uranylu – infračervená a Ramanova spektra minerálů uranylu II. Uhličitany uranylu. Bull. mineral.-petrolog. odd. Nár. muz. (Praha) 13, 62-72.

Chernorukov N. G., Knyazev A. V., Vlasova E .V., Kuznetsova N. Yu. (2009) Physico-chemical investigation of uranyl carbonates of alkaline-earth metals. Radiokhim. 51, 213-217.

Jolivet J. P., Thomas Y., Taravel B. (1980) Vibrational study of coordinated CO₃^2- ions. J. Mol. Struct. 60, 93-98.

Jones G. C., Jackson B. (1993) Infrared transmission spectra of carbonate minerals. Chapman and Hall, London.

Koglin E., Schenk H. J., Schwochau K. (1979) Vibrational and low temperature optical spectra of the uranyl tricarbonato complex [UO₂(CO₃)₃]^4–. Spectrochim. A. 35A, 641-647.

Libowitzky E. (1999) Correlation of O-H stretching frequencies and O-H×××O hydrogen bond lengths in minerals. Monats. Chem. 130, 1047-1059.

Mayer H., Mereiter K. (1986) Synthetic bayleyite, Mg₂[UO₂(CO₃)₃].18H₂O: Thermochemistry, crystallography and crystal structure. Tschermaks Miner. Petr. Mitt. 35, 133-146.

Mereiter K. (1986) Synthetic swartzite, CaMg[UO₂(CO₃)₃].12H₂O, and its strontium analogue SrMg[UO₂(CO₃)₃].12H₂O: Crystallography and crystal structures. N. Jb. Miner. Mh. 11, 481-492.

Mereiter K. (2013) Description and crystal structure of albrechtschraufite, MgCa₄F₂[UO₂(CO₃)₃]₂.17-18H₂O. Mineral. Petrol. 107, 179-188.

Ondruš P., Veselovský F., Hloušek J., Skála R., Vavřín I., Frýda J., Čejka J., Gabašová A. (1997) Secondary minerals of the Jáchymov (Joachimsthal) ore district. J. Czech Geol. Soc. 42, 3-6.

Ondruš P., Veselovský F., Gabašová A., Hloušek J., Šrein V., Vavřín I., Skála R., Sejkora J., Drábek M. (2003) Primary minerals of the Jáchymov ore district. J. Czech Geol. Soc. 48, 19-147.

Petříček V., Dušek M., Palatinus L. (2006) Jana2006. The crystallographic computing system. Institute of Physics, Praha, Czech Republic. www.jana.fzu.cz

Petříček V., Dušek M., Palatinus L. (2014) Crystallographic computing system JANA2006: General features. Z. Kristall. DOI: 10.1515/zkri-2013-1737.

Plášil J. (2014) Oxidation–hydration weathering of uraninite: the current state-of-knowledge. J. Geosci. 59, 99-114.

Plášil J., Fejfarová K., Škoda R., Dušek M., Čejka J., 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.). Mineral. Petrol. 107, 211-219.

Pouchou J. L., Pichoir F. (1985) “PAP” (φρZ) procedure for improved quantitative microanalysis. In: Microbeam Analysis (J. T. Armstrong, ed.). San Francisco Press, San Francisco, 104-106.

Sejkora J., Babka K., Pavlíček R. (2012) Saléeit z uranového rudního revíru Jáchymov (Česká republika). Bull. mineral.-petrolog. odd. Nár. muz. (Praha) 20, 2, 208-212.

Sejkora J., Plášil J., Bureš B. (2013) Neobvyklá asociace supergenních minerálů uranu ze žíly Jan Evangelista, Jáchymov (Česká republika). Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha) 21, 2, 143-156.

Zeying Z., Keding L., Zhangru Ch. (1985) The crystal structure of bayleyite. Sci. Ch. Chem. 28, 344-350.