From structure topology to chemical composition. XXIII. Revision of the crystal structure and chemical formula of zvyaginite, Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia
The crystal structure and chemical formula of zvyaginite, ideally Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a lamprophyllite-group mineral of the seidozerite supergroup from the type locality, Mt. Malyi Punkaruaiv, Lovozero alkaline massif, Kola Peninsula, Russia have been revised. The crystal structurewas r...
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Online Access: | http://hdl.handle.net/2434/555487 https://doi.org/10.1180/minmag.2017.081.015 |
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ftunivmilanoair:oai:air.unimi.it:2434/555487 2024-02-11T10:05:34+01:00 From structure topology to chemical composition. XXIII. Revision of the crystal structure and chemical formula of zvyaginite, Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia Sokolova, E. Genovese, A. Falqui, A. Hawthorne, F. C. Cámara, F. E. Sokolova A. Genovese A. Falqui F.C. Hawthorne F. Cámara 2017-12 http://hdl.handle.net/2434/555487 https://doi.org/10.1180/minmag.2017.081.015 eng eng Mineralogical Society info:eu-repo/semantics/altIdentifier/wos/WOS:000419618300013 volume:81 issue:6 firstpage:1533 lastpage:1550 numberofpages:18 journal:MINERALOGICAL MAGAZINE http://hdl.handle.net/2434/555487 doi:10.1180/minmag.2017.081.015 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85038894072 info:eu-repo/semantics/openAccess chemical formula crystal-structure refinement electron diffraction emp analysi epistolite hrtem lamprophyllite group seidozerite supergroup TS-block mineral zvyaginite geochemistry and petrology Settore GEO/06 - Mineralogia info:eu-repo/semantics/article 2017 ftunivmilanoair https://doi.org/10.1180/minmag.2017.081.015 2024-01-16T23:28:32Z The crystal structure and chemical formula of zvyaginite, ideally Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a lamprophyllite-group mineral of the seidozerite supergroup from the type locality, Mt. Malyi Punkaruaiv, Lovozero alkaline massif, Kola Peninsula, Russia have been revised. The crystal structurewas refined with a new origin in space group C1, a = 10.769(2), b = 14.276(3), c = 12.101(2) Å, α = 105.45(3), β = 95.17(3), γ = 90.04(3)°, V = 1785.3(3.2) Å3, R1 = 9.23%. The electron-microprobe analysis gave the following empirical formula [calculated on 22 (O + F)]: (Na0.75Ca0.09K0.04 □1.12)σ2 (Na1.12Zn0.88Mn0.17Fe2+ 0.04 □0.79)σ3 (Nb1.68Ti1.25Al0.07)σ3 (Si4.03O14)O2 [(OH)1.11F0.89]σ2(H2O)4, Z = 4. Electron-diffraction patterns have prominent streaking along c∗and HRTEM images show an intergrowth of crystalline zvyaginite with two distinct phases, both of which are partially amorphous. The crystal structure of zvyaginite is an array of TS (Titanium-Silicate) blocks connected via hydrogen bonds between H2O groups. The TS block consists of HOH sheets (H = heteropolyhedral, O = octahedral) parallel to (001). In the O sheet, the [6]MH(1,5) sites are occupied mainly by Ti, Zn and Na and the [6]MO(2,3) sites are occupied by Na at less than 50%. In the H sheet, the [6]MH(1,2) sites are occupied mainly by Nb and the [8]AP(1) and [8]AP(2) sites are occupied mainly by Na and □. The MH and AP polyhedra and Si2O7 groups constitute the H sheet. The ideal structural formula is Na Nb2NaZnTi(Si2O7)2O2(OH)2(H2O)4. Zvyaginite is a Zn-bearing and Na-poor analogue of epistolite, ideally (Na)Nb2Na3Ti(Si2O7)2O2(OH)2(H2O)4. Epistolite and zvyaginite are related by the following substitution in the O sheet of the TS-block: (Na+ 2 )epi↔Zn2+ zvy +□zvy. The doubling of the t1 and t2 translations of zvyaginite relative to those of epistolite is due to the order of Zn and Na along a (t1) and b (t2) in the O sheet of zvyaginite. Article in Journal/Newspaper kola peninsula The University of Milan: Archivio Istituzionale della Ricerca (AIR) Kola Peninsula Lovozero ENVELOPE(35.016,35.016,68.006,68.006) Mineralogical Magazine 81 6 1533 1550 |
institution |
Open Polar |
collection |
The University of Milan: Archivio Istituzionale della Ricerca (AIR) |
op_collection_id |
ftunivmilanoair |
language |
English |
topic |
chemical formula crystal-structure refinement electron diffraction emp analysi epistolite hrtem lamprophyllite group seidozerite supergroup TS-block mineral zvyaginite geochemistry and petrology Settore GEO/06 - Mineralogia |
spellingShingle |
chemical formula crystal-structure refinement electron diffraction emp analysi epistolite hrtem lamprophyllite group seidozerite supergroup TS-block mineral zvyaginite geochemistry and petrology Settore GEO/06 - Mineralogia Sokolova, E. Genovese, A. Falqui, A. Hawthorne, F. C. Cámara, F. From structure topology to chemical composition. XXIII. Revision of the crystal structure and chemical formula of zvyaginite, Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia |
topic_facet |
chemical formula crystal-structure refinement electron diffraction emp analysi epistolite hrtem lamprophyllite group seidozerite supergroup TS-block mineral zvyaginite geochemistry and petrology Settore GEO/06 - Mineralogia |
description |
The crystal structure and chemical formula of zvyaginite, ideally Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a lamprophyllite-group mineral of the seidozerite supergroup from the type locality, Mt. Malyi Punkaruaiv, Lovozero alkaline massif, Kola Peninsula, Russia have been revised. The crystal structurewas refined with a new origin in space group C1, a = 10.769(2), b = 14.276(3), c = 12.101(2) Å, α = 105.45(3), β = 95.17(3), γ = 90.04(3)°, V = 1785.3(3.2) Å3, R1 = 9.23%. The electron-microprobe analysis gave the following empirical formula [calculated on 22 (O + F)]: (Na0.75Ca0.09K0.04 □1.12)σ2 (Na1.12Zn0.88Mn0.17Fe2+ 0.04 □0.79)σ3 (Nb1.68Ti1.25Al0.07)σ3 (Si4.03O14)O2 [(OH)1.11F0.89]σ2(H2O)4, Z = 4. Electron-diffraction patterns have prominent streaking along c∗and HRTEM images show an intergrowth of crystalline zvyaginite with two distinct phases, both of which are partially amorphous. The crystal structure of zvyaginite is an array of TS (Titanium-Silicate) blocks connected via hydrogen bonds between H2O groups. The TS block consists of HOH sheets (H = heteropolyhedral, O = octahedral) parallel to (001). In the O sheet, the [6]MH(1,5) sites are occupied mainly by Ti, Zn and Na and the [6]MO(2,3) sites are occupied by Na at less than 50%. In the H sheet, the [6]MH(1,2) sites are occupied mainly by Nb and the [8]AP(1) and [8]AP(2) sites are occupied mainly by Na and □. The MH and AP polyhedra and Si2O7 groups constitute the H sheet. The ideal structural formula is Na Nb2NaZnTi(Si2O7)2O2(OH)2(H2O)4. Zvyaginite is a Zn-bearing and Na-poor analogue of epistolite, ideally (Na)Nb2Na3Ti(Si2O7)2O2(OH)2(H2O)4. Epistolite and zvyaginite are related by the following substitution in the O sheet of the TS-block: (Na+ 2 )epi↔Zn2+ zvy +□zvy. The doubling of the t1 and t2 translations of zvyaginite relative to those of epistolite is due to the order of Zn and Na along a (t1) and b (t2) in the O sheet of zvyaginite. |
author2 |
E. Sokolova A. Genovese A. Falqui F.C. Hawthorne F. Cámara |
format |
Article in Journal/Newspaper |
author |
Sokolova, E. Genovese, A. Falqui, A. Hawthorne, F. C. Cámara, F. |
author_facet |
Sokolova, E. Genovese, A. Falqui, A. Hawthorne, F. C. Cámara, F. |
author_sort |
Sokolova, E. |
title |
From structure topology to chemical composition. XXIII. Revision of the crystal structure and chemical formula of zvyaginite, Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia |
title_short |
From structure topology to chemical composition. XXIII. Revision of the crystal structure and chemical formula of zvyaginite, Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia |
title_full |
From structure topology to chemical composition. XXIII. Revision of the crystal structure and chemical formula of zvyaginite, Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia |
title_fullStr |
From structure topology to chemical composition. XXIII. Revision of the crystal structure and chemical formula of zvyaginite, Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia |
title_full_unstemmed |
From structure topology to chemical composition. XXIII. Revision of the crystal structure and chemical formula of zvyaginite, Na2ZnTiNb2(Si2O7)2O2(OH)2(H2O)4, a seidozerite-supergroup mineral from the Lovozero alkaline massif, Kola peninsula, Russia |
title_sort |
from structure topology to chemical composition. xxiii. revision of the crystal structure and chemical formula of zvyaginite, na2zntinb2(si2o7)2o2(oh)2(h2o)4, a seidozerite-supergroup mineral from the lovozero alkaline massif, kola peninsula, russia |
publisher |
Mineralogical Society |
publishDate |
2017 |
url |
http://hdl.handle.net/2434/555487 https://doi.org/10.1180/minmag.2017.081.015 |
long_lat |
ENVELOPE(35.016,35.016,68.006,68.006) |
geographic |
Kola Peninsula Lovozero |
geographic_facet |
Kola Peninsula Lovozero |
genre |
kola peninsula |
genre_facet |
kola peninsula |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000419618300013 volume:81 issue:6 firstpage:1533 lastpage:1550 numberofpages:18 journal:MINERALOGICAL MAGAZINE http://hdl.handle.net/2434/555487 doi:10.1180/minmag.2017.081.015 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85038894072 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1180/minmag.2017.081.015 |
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Mineralogical Magazine |
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81 |
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1533 |
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1550 |
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