Prossima pubblicazione.
Referenza:
▪ Plášil, J., Škoda, R., Čeika, J., Bourgoin, V., Boulliard, J.-C. (2016): Crystal structure of the uranyl-oxide mineral rameauite. European Journal of Mineralogy, 28, (in press).
Abstract:
Rameauite is a rare supergene uranyl-oxide hydroxy-hydrate mineral that forms during hydration-oxidation weathering of uraninite. On the basis of single-crystal X-ray diffraction data collected on a microfocus source, rameauite is monoclinic, space group Cc, with a = 13.9458(19), b = 14.3105(19), c = 13.8959(18) Å, β = 118.477(14)°, V = 2437.7(6) Å3 and Z = 4, with Dcalc = 5.467 g cm-3. The structure of rameauite (R = 0.060 for 1698 unique observed reflections) contains sheets of the β-U3O8 topology, with both UO6 and UO7 bipyramids, which is similar to the sheets found in spriggite, ianthinite and wyartite. The sheets alternate with the interlayer, which contains K+, Ca2+ and H2O molecules. Interstitial cations are linked into infinite chains that extend along [10-1]. Adjacent sheets are linked through K–O, Ca–O and H-bonds. The structural formula of rameauite is K2Ca(H2[3]O)1(H2[5]O)4[(UO2)6O6(OH)4](H2[4]O)1. The empirical formula obtained from the average of eight electron-microprobe analyses is (on the basis of 6 U p.f.u.) K1.87(Ca1.10Sr0.04)Σ1.14[(UO2)6O6(OH)4.15]·6H2O. The Raman spectrum is dominated by U–O and O–H vibrations. A discussion of related uranyl-oxide minerals is given.
Crystal structure and new formula of rameauite
- Marco E. Ciriotti
- Messaggi: 31645
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Crystal structure and new formula of rameauite
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 31645
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Crystal structure and new formula of rameauite
Pubblicazione effettuata.
Referenza:
▪ Plášil, J., Škoda, R., Čeika, J., Bourgoin, V., Boulliard, J.-C. (2016): Crystal structure of the uranyl-oxide mineral rameauite. European Journal of Mineralogy, 28, 959-967.
Referenza:
▪ Plášil, J., Škoda, R., Čeika, J., Bourgoin, V., Boulliard, J.-C. (2016): Crystal structure of the uranyl-oxide mineral rameauite. European Journal of Mineralogy, 28, 959-967.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
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