Prossima pubblicazione.
Referenza:
▪ Bosi, F., Skogby, H., Hovis, G.L. (2023): Crystal chemistry of povondraite by SCXRD, EMPA, Mössbauer spectroscopy and FTIR. Mineralogical Magazine, 87, 178-185.
Abstract:
Five povondraite crystals from San Francisco Mine, Villa Tunari, Bolivia, have been structurally and chemically characterized by single-crystal X-ray diffraction and electron microprobe analysis. For the first time, this characterization is accompanied by Mössbauer spectroscopic and single-crystal infrared spectroscopic data, which show the exclusive presence of Fe3+ at both the octahedrally-coordinated Y and Z sites as well as slight disorder of (OH) and O over the O(1) and O(3) sites. The data obtained along with those for earlier-studied bosiite and oxy-dravite oxytourmalines show a complete substitution series described by the reaction YFe3+3 + ZMg +ZFe3+4 ↔ YAl2 + YMg + ZAl5 (i.e. Fe3+Al–1) with variation of the structural parameters dominated by Fe3+ (or Al). Povondraite is the tourmaline member having the largest unitcell parameters due to the larger size of Fe3+ relative to other trivalent cations (V > Cr > Al). In the tourmaline-supergroup minerals, the a and c unit-cell parameters vary from ~15.60 Å to ~16.25 Å and ~7.00 Å to ~7.50 Å, respectively. Their values increase with increasing Fe3+ or decreasing Al. Endmember compositions related to the smallest and largest a- and c-parameters are, respectively, NaAl3Al6(Si3B3O18)(BO3)3(OH)3(OH) (synthetic tourmaline) and NaFe3+3(Fe3+4Mg2)(Si6O18)(BO3)3(OH)3O (povondraite).
Crystal chemistry of povondraite by SCXRD, EMPA, Mössbauer spectroscopy and FTIR
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Crystal chemistry of povondraite by SCXRD, EMPA, Mössbauer spectroscopy and FTIR
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: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: Crystal chemistry of povondraite by SCXRD, EMPA, Mössbauer spectroscopy and FTIR
Pubblicazione effettuata.
Referenza:
▪ Bosi, F., Skogby, H., Hovis, G.L. (2023): Crystal chemistry of povondraite by SCXRD, EMPA, Mössbauer spectroscopy and FTIR. Mineralogical Magazine, 87, 178-185.
Referenza:
▪ Bosi, F., Skogby, H., Hovis, G.L. (2023): Crystal chemistry of povondraite by SCXRD, EMPA, Mössbauer spectroscopy and FTIR. Mineralogical Magazine, 87, 178-185.
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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