New data on cafarsite: reinvestigation of its crystal structure and chemical composition
- 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:
New data on cafarsite: reinvestigation of its crystal structure and chemical composition
Prossima pubblicazione.
Referenza:
▪ Cametti, G., Nagashima, M., Fisch, M., Armbruster, T. (2018): New data on cafarsite: reinvestigation of its crystal structure and chemical composition. European Journal of Mineralogy, 30, (in press).
Referenza:
▪ Cametti, G., Nagashima, M., Fisch, M., Armbruster, T. (2018): New data on cafarsite: reinvestigation of its crystal structure and chemical composition. European Journal of Mineralogy, 30, (in press).
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»
Re: New data on cafarsite: reinvestigation of its crystal structure and chemical composition
Ciao Marco.
Quando arriva puoi passarmene una copia per favore?
Grazie mille, a presto.
Quando arriva puoi passarmene una copia per favore?
Grazie mille, a presto.
Mirco
"Molte volte le persone ci sembrano grandi solo perchè le guardiamo stando in ginocchio"
"Molte volte le persone ci sembrano grandi solo perchè le guardiamo stando in ginocchio"
- 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: New data on cafarsite: reinvestigation of its crystal structure and chemical composition
Certo, Mirco. Non so però se ho la tua mail aggiornata.Ciao Marco.
Quando arriva puoi passarmene una copia per favore?
Grazie mille, a presto.
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»
Re: New data on cafarsite: reinvestigation of its crystal structure and chemical composition
Tranquillo Marco, la mia mail è sempre quella, ricevo sempre le tue newsletter su Tavagnasco e simili.
Grazie mille.
Grazie mille.
Mirco
"Molte volte le persone ci sembrano grandi solo perchè le guardiamo stando in ginocchio"
"Molte volte le persone ci sembrano grandi solo perchè le guardiamo stando in ginocchio"
- 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: New data on cafarsite: reinvestigation of its crystal structure and chemical composition
Referenza:
▪ Cametti, G., Nagashima, M., Fisch, M., Armbruster, T. (2018): New data on cafarsite: reinvestigation of its crystal structure and chemical composition. European Journal of Mineralogy, 30, (in press).
Abstract:
The crystal structure of cafarsite from Wanni glacier, Monte Cervandone, was re-investigated by single-crystal X-ray diffraction (space group Pn-3, R1 = 0.022) and new electron-microprobe analyses. The REE (mainly Ce and Y) were found to substitute Ca. A new anion site, four-coordinated by Ca, was located by difference Fourier analysis and refined with F scattering factors. Two octahedral sites (Ti1 and Fe2) are occupied by mainly Ti and Fe3+, replacing each ther whereas the octahedral site Mn1 hosts Mn2+ and Fe2+. The new structure refinements and chemical analyses lead to the simplified chemical formula (Ca7.8Na0.8Mn0.5REE0.4)Σ9.5(Ti3.9Fe3+2.1Fe2+0.9Mn2+0.1)Σ7(AsO3)14F0.5. According to our findings, there is no evidence for either H2O or OH in the structure. In contrast to the original study of 1977, the structure has no significant cation vacancies and is based on 14 AsO3 groups per formula unit, not on 12 AsO3 as previously suggested.
▪ Cametti, G., Nagashima, M., Fisch, M., Armbruster, T. (2018): New data on cafarsite: reinvestigation of its crystal structure and chemical composition. European Journal of Mineralogy, 30, (in press).
Abstract:
The crystal structure of cafarsite from Wanni glacier, Monte Cervandone, was re-investigated by single-crystal X-ray diffraction (space group Pn-3, R1 = 0.022) and new electron-microprobe analyses. The REE (mainly Ce and Y) were found to substitute Ca. A new anion site, four-coordinated by Ca, was located by difference Fourier analysis and refined with F scattering factors. Two octahedral sites (Ti1 and Fe2) are occupied by mainly Ti and Fe3+, replacing each ther whereas the octahedral site Mn1 hosts Mn2+ and Fe2+. The new structure refinements and chemical analyses lead to the simplified chemical formula (Ca7.8Na0.8Mn0.5REE0.4)Σ9.5(Ti3.9Fe3+2.1Fe2+0.9Mn2+0.1)Σ7(AsO3)14F0.5. According to our findings, there is no evidence for either H2O or OH in the structure. In contrast to the original study of 1977, the structure has no significant cation vacancies and is based on 14 AsO3 groups per formula unit, not on 12 AsO3 as previously suggested.
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: New data on cafarsite: reinvestigation of its crystal structure and chemical composition
Nel lavoro di Cametti et al. (2018) il numero totale degli elementi è 33 in luogo dei 32 presenti nel lavoro di Gatta et al. (2018): viewtopic.php?f=5&t=14450&p=246676&hili ... te#p246676
Conseguentemente le formule differiscono un pochino...
Conseguentemente le formule differiscono un pochino...
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: New data on cafarsite: reinvestigation of its crystal structure and chemical composition
Pubblicazione effettuata.
Referenza:
▪ Cametti, G., Nagashima, M., Fisch, M., Armbruster, T. (2018): New data on cafarsite: reinvestigation of its crystal structure and chemical composition. European Journal of Mineralogy, 30, 859-868.
Referenza:
▪ Cametti, G., Nagashima, M., Fisch, M., Armbruster, T. (2018): New data on cafarsite: reinvestigation of its crystal structure and chemical composition. European Journal of Mineralogy, 30, 859-868.
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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