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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

Published online by Cambridge University Press:  26 January 2018

E. Sokolova ,
A. Genovese ,
A. Falqui ,
F.C. Hawthorne  and
F. Cámara
E. Sokolova*
Affiliation:
Department of Geological Sciences, University of Manitoba, 125 Dysart Road, WinnipegMBR3T 2N2 Canada
A. Genovese
Affiliation:
Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Bldg. 2, Thuwal 23955-6900, Saudi Arabia
A. Falqui
Affiliation:
Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Bldg. 2, Thuwal 23955-6900, Saudi Arabia
F.C. Hawthorne
Affiliation:
Department of Geological Sciences, University of Manitoba, 125 Dysart Road, WinnipegMBR3T 2N2 Canada
*
* E-mail: [email protected]
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Abstract

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]MO(1,4,5) 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□Nb2NaZn□Ti(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: (Naþ 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.

Keywords

zvyaginitecrystal-structure refinementHRTEMelectron diffractionEMP analysischemical formulalamprophyllite groupseidozerite supergroupTS-block mineralsepistolite
Type
Research Article
Information
Mineralogical Magazine , Volume 81 , Issue 6 , December 2017 , pp. 1533 - 1550
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2017

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References

Aksenov, S.M., Rastsvetaeva, R.K. and Chukanov, N.V. (2014) The crystal structure of emmerichite Ba2Na3 Fe3+Ti2(Si2O7)2O2F2, a new lamprophyllite-group mineral. Zeitschrift für Kristallographie, 229, 1–7.CrossRefGoogle Scholar
Andrade, M.B., Yang, H., Downs, R.T., Färber, G., Contreira Filho, R.R., Evans, S.H., Loehn, C.W. and Schumer, B.N. (2017) Fluorlamprophyllite, Na3(SrNa) Ti3(Si2O7)O2F2, a new mineral from Poços de Caldas alkaline massif,Morro do Serrote, Mines Gerais, Brazil. Mineralogical Magazine, https://doi.org/10.1180/minmag.2017.081.027 Google Scholar
Brown, I.D. (1981) The bond-valence method: an empirical approach to chemical structure and bonding. Pp. 1–30 in: Structure and Bonding in Crystals II (M. O’Keeffe and A. Navrotsky, editors). Academic Press, New York.Google Scholar
Cámara, F. and Sokolova, E. (2007) From structure topology to chemical composition. VI. Titanium silicates: the crystal structure and crystal chemistry of bornemanite, a group III Ti-disilicate mineral. Mineralogical Magazine, 71, 593–610.CrossRefGoogle Scholar
Cámara, F. and Sokolova, E. (2009) From structure topology to chemical composition. X. Titanium silicates: the crystal structure and crystal chemistry of nechelyustovite, a group III Ti-disilicate mineral. Mineralogical Magazine, 73, 887–897.Google Scholar
Cámara, F., Sokolova, E., Hawthorne, F.C. and Abdu, Y. (2008) From structure topology to chemical composition. IX. Titanium silicates: revision of the crystal chemistry of lomonosovite and murmanite, Group-IV minerals. Mineralogical Magazine, 72, 1207–1228.CrossRefGoogle Scholar
Cámara, F., Sokolova, E. and Hawthorne, F.C. (2012) Kazanskyite, BaTiNbNa3Ti(Si2O7)2O2 (OH)2(H2O)4, a Group-III Ti-disilicate mineral from the Khibiny alkaline massif, Kola Peninsula, Russia: description and crystal structure. Mineralogical Magazine, 76, 473–492.CrossRefGoogle Scholar
Cámara, F., Sokolova, E., Abdu, Y.A. and Hawthorne, F.C. (2014) Saamite, Ba□TiNbNa3Ti(Si2O7)2O2(OH)2 (H2O)2, a Group-III Ti-disilicate mineral from the Khibiny alkaline massif, Kola Peninsula, Russia: description and crystal structure. The Canadian Mineralogist, 52, 745–761.CrossRefGoogle Scholar
Chukanov, N.V., Pekov, I.V., Rastsvetaeva, R.K., Aksenov, S.M., Zadov, A.E., Van, K.V., Blass, G., Schüller, W. and Ternes, B. (2012) Lileyite, Bа2(Na, Fe,Ca)3MgTi2(Si2O7)2O2F2, a new lamprophyllitegroup mineral from the Eifel volcanic area, Germany. European Journal of Mineralogy, 24, 181–188.CrossRefGoogle Scholar
Ercit, T.S., Cooper, M.A. and Hawthorne, F.C. (1998) The crystal structure of vuonnemite, Na11Ti4+ Nb2(Si2O7)2(PO4)2O3(F,OH), a phosphate-bearing sorosilicate of the lomonosovite group. The Canadian Mineralogist, 37, 1311–1320.Google Scholar
Khomyakov, A.P. (1995) Mineralogy of Hyperagpaitic Alkaline Rocks. Clarendon Press, Oxford, UK.Google Scholar
Krivovichev, S.V., Armbruster, T., Yakovenchuk, V.N., Pakhomovsky, Ya.A. and Men’shikov, Yu., P. (2003) Crystal structures of lamprophyllite-2M and lamprophyllite- 2O from the Lovozero alkaline massif, Kola peninsula, Russia. European Journal of Mineralogy, 15, 711–718.CrossRefGoogle Scholar
Lykova, I.S., Pekov, I.V., Zubkova, N.V., Yapaskurt, V.O., Chervonnaya, N.A., Zolotarev, A.A. and Giester, G. (2015) Crystal chemistry of cation-exchanged forms of epistolite-group minerals. Part II. Vigrishinite and Zn-exchanged murmanite. European Journal of Mineralogy, 27, 669–682.CrossRefGoogle Scholar
Pekov, I.V., Britvin, S.N., Zubkova, N.V., Chukanov, N.V., Bryzgalov, I.A., Lykova, I.S., Belakovskiy, D.I. and Pushcharovsky, D.Yu. (2013) Vigrishinite, Zn2Ti4–x Si4O14(OH,H2O,□)8, a new mineral from the Lovozero alkaline complex, Kola Peninsula, Russia. Geology of Ore Deposits, 55, 575–586.CrossRefGoogle Scholar
Pekov, I.V., Lykova, I.S., Chukanov, N.V., Yapaskurt, V. O., Belakovskiy, D.I., Zolotarev Jr, A.A. and Zubkova, N.V. (2014) Zvyaginite, NaZnNb2Ti(Si2O7)2O(OH, F)3(H2O)4+x (x > 1), a new mineral of the epistolite group from the Lovozero alkaline pluton, Kola Peninsula, Russia. Geology of Ore Deposits, 56, 644–656.CrossRefGoogle Scholar
Pouchou, J.L. and Pichoir, F. (1985) “PAP” j(ρΖ) procedure for improved quantitative microanalysis. Pp. 104–106 in: Microbeam Analysis (J.T. Armstrong, editor). San Francisco Press, San Francisco, California, USA.Google Scholar
Rastsvetaeva, R.K. and Chukanov, N.V. (1999) Crystal structure of a new high-barium analogue of lamprophyllite with a primitive unit cell. Doklady Chemistry, 368, 228–231.Google Scholar
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751–767.Google Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112–122.Google Scholar
Sokolova, E. (2006) From structure topology to chemical composition. I. Structural hierarchy and stereochemistry in titanium disilicate minerals. The Canadian Mineralogist, 44, 1273–1330.CrossRefGoogle Scholar
Sokolova, E. and Cámara, F. (2007) From structure topology to chemical composition. II. Titanium silicates: revision of the crystal structure and chemical formula of delindeite. The Canadian Mineralogist, 45, 1247–1261.CrossRefGoogle Scholar
Sokolova, E. and Cámara, F. (2008) From structure topology to chemical composition. III. Titanium silicates: crystal chemistry of barytolamprophyllite. The Canadian Mineralogist, 46, 403–412.CrossRefGoogle Scholar
Sokolova, E. and Cámara, F. (2013) From structure topology to chemical composition. XVI. New developments in the crystal chemistry and prediction of new structure topologies for titanium disilicate minerals with the TS block. The Canadian Mineralogist, 51, 861–891.CrossRefGoogle Scholar
Sokolova, E. andCámara, F. (2016) Fromstructure topology to chemical composition. XXI. Understanding the crystal chemistry of barium in TS-block minerals. The Canadian Mineralogist, 54, 79–95.CrossRefGoogle Scholar
Sokolova, E. and Cámara, F. (2017) The seidozerite supergroup of TS-block minerals: nomenclature and classification, with change of the following names rinkite to rinkite-(Ce), mosandrite to mosandrite-(Ce), hainite to hainite-(Y) and innelite-1T to innelite-1A. Mineralogical Magazine, 81, 1457–1484.CrossRefGoogle Scholar
Sokolova, E. and Hawthorne, F.C. (2004) The crystal chemistry of epistolite. The Canadian Mineralogist, 42, 797–806.CrossRefGoogle Scholar
Sokolova, E. and Hawthorne, F.C. (2008) From structure topology to chemical composition. IV. Titanium silicates: the orthorhombic polytype of nabalamprophyllite from Lovozero massif, Kola Peninsula, Russia. The Canadian Mineralogist, 46, 1323–1331.CrossRefGoogle Scholar
Sokolova, E., Cámara, F. and Hawthorne, F.C. (2011) From structure topology to chemical composition. XI. Titanium silicates: crystal structures of innelite-1T and innelite-2M from the Inagli massif, Yakutia, Russia and the crystal chemistry of innelite. Mineralogical Magazine, 75, 2495–2518.CrossRefGoogle Scholar
Wilson, A.J.C. (editor) (1992) International Tables for Crystallography. Volume C: Mathematical, physical and chemical tables. Kluwer Academic Publishers, Dordrecht, The Netherlands.Google Scholar