Prossima pubblicazione.
Referenza:
▪ Grey, I.E. & Kampf, A.R. (2018): Zeolitic water in strunzite-group minerals. Mineralogical Magazine, 82, (in press).
Abstract:
The crystal structures have been refined for the first time for the strunzite-group minerals ferristrunzite and ferrostrunzite. Structure refinements are also presented for strunzite from three different localities. A common feature of all refined structural models is the presence of zeolitic water in the interlayer region, displaced by 0.4-0.5 Å from an inversion centre at (½ 0 ½). The refined occupancy of the site ranged from 44% to 100% in the samples studied. H-bonding associated with the zeolitic water causes large displacements, up to 0.7 Å, of neighbouring coordinated water molecules, relative to the structure with no zeolitic water. A new formula is proposed for strunzite-group minerals with divalent interlayer cations as M2+Fe3+2(PO4)2(OH)2·(6.5-x)H2O; M = Mn, Fe, Zn and 0 < x < 0.5 accounts for varying degrees of dehydration. For ferristrunzite and other potential strunzite-group members with trivalent cations in the interlayer octahedron, the formula is M3+Fe3+2(PO4)2(OH)3·(5.5-x)H2O.
Strunzite group
Ferristrunzite Fe3+Fe3+2(PO4)2(OH)2(H2O)6.32
Ferrostrunzite Fe2+Fe3+2(PO4)2(OH)3(H2O)5.5
Strunzite Mn2+Fe3+2(PO4)2(OH)2(H2O)6.33
Zincostrunzite ZnFe3+2(PO4)2(OH)2(H2O)6
Zeolitic water in strunzite-group minerals
- 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:
Zeolitic water in strunzite-group minerals
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: Zeolitic water in strunzite-group minerals
Pubblicazione effettuata.
Referenza:
▪ Grey, I.E. & Kampf, A.R. (2018): Zeolitic water in strunzite-group minerals. Mineralogical Magazine, 82, 291-299.
Abstract:
The crystal structures have been refined for the first time for the strunzite-group minerals ferristrunzite and ferrostrunzite. Structure refinements are also presented for strunzite from three different localities. A common feature of all refined structural models is the presence of zeolitic water in the interlayer region, displaced by 0.4-0.5 Å from an inversion centre at (½ 0 ½). The refined occupancy of the site ranged from 44% to 100% in the samples studied. H-bonding associated with the zeolitic water causes large displacements, up to 0.7 Å, of neighbouring coordinated water molecules, relative to the structure with no zeolitic water. A new formula is proposed for strunzite-group minerals with divalent interlayer cations as M2+Fe3+2(PO4)2(OH)2·(6.5-x)H2O; M = Mn, Fe, Zn and 0 < x < 0.5 accounts for varying degrees of dehydration. For ferristrunzite and other potential strunzite-group members with trivalent cations in the interlayer octahedron, the formula is M3+Fe3+2(PO4)2(OH)3·(5.5-x)H2O.
Referenza:
▪ Grey, I.E. & Kampf, A.R. (2018): Zeolitic water in strunzite-group minerals. Mineralogical Magazine, 82, 291-299.
Abstract:
The crystal structures have been refined for the first time for the strunzite-group minerals ferristrunzite and ferrostrunzite. Structure refinements are also presented for strunzite from three different localities. A common feature of all refined structural models is the presence of zeolitic water in the interlayer region, displaced by 0.4-0.5 Å from an inversion centre at (½ 0 ½). The refined occupancy of the site ranged from 44% to 100% in the samples studied. H-bonding associated with the zeolitic water causes large displacements, up to 0.7 Å, of neighbouring coordinated water molecules, relative to the structure with no zeolitic water. A new formula is proposed for strunzite-group minerals with divalent interlayer cations as M2+Fe3+2(PO4)2(OH)2·(6.5-x)H2O; M = Mn, Fe, Zn and 0 < x < 0.5 accounts for varying degrees of dehydration. For ferristrunzite and other potential strunzite-group members with trivalent cations in the interlayer octahedron, the formula is M3+Fe3+2(PO4)2(OH)3·(5.5-x)H2O.
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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