Skip to main content Accessibility help
×
Home

Crystal structure of a synthetic aluminoan tantalian titanite: a reconnaissance study

  • R. P. Liferovich (a1) and R. H. Mitchell (a1)

Abstract

A synthetic analogue, Ca(Ti0.6Al0.2Ta0.16Nb0.04)OSiO4, of an aluminoan tantalian titanite previously described from Craveggia pegmatite (Piemonte, Italy) has been prepared by a ceramic synthesis technique and its crystal structure determined by Rietveld analysis of the powder X-ray diffraction pattern. The synthetic Al-Ta-Nb-rich titanite adopts space group A2/a implying that substitutions at the single octahedral site destroy the coherence of the off-centering of octahedral chains in the titanite structure resulting in a P21/a → A2/a phase transition. Unit-cell dimensions obtained for the Al-Ta-Nb-rich titanite are: a = 7.0649(1) Å; b = 8.7187(1) Å; c = 6.5701(1) Å; β = 113.755(1)°, V = 370.41(1) Å3. The extensive replacement of Ti by Al, Ta and Nb results in a considerable decrease in the distortion of all coordination polyhedra in the structure of this titanite. These structural data suggest that a solid solution CaTi1-x (Al x/2 [Ta,Nb] x/2)OSiO4 (0 ≤ x ≤ 0.4) adopting the titanite structure might exist.

Copyright

Corresponding author

Footnotes

Hide All

Permanent address: Geological Institute KSC RAS, 14 Fersmana St., Apatity, 184200 Russia

Footnotes

References

Hide All
Angel, R.J., Kunz, M., Miletich, R., Woodland, A.B., Koch, M. and Xirochakis, D. (1999) High-pressure phase transitions in CaTiOSiO4 titanite. Phase Transitions, 68, 533543.
Balić-Žunić, T. and Vicković, I. (1996) IVTON - a program for the calculation of geometrical aspects of crystal structures and some crystal chemical applications. Journal of Applied Crystallography, 29, 305306.
Černý, P. and Riva di Sanseverino, L. (1972) Comments on crystal chemistry of titanite. Neues Jahrbuch fur Mineralogie Monatshefte, 97–103.
Černý, B.J., Chapman, R. and Hinthorne, J.R. (1981) Niobian titanite from the Huron claim pegmatite, southeastern Manitoba. The Canadian Mineralogist, 19,549552.
Černý, P., Novak, M. and Chapman, R. (1995) The Al(Nb,Ta)Ti_2 substitution in titanite: the emergence of a new species? Mineralogy and Petrology, 52, 6173.
Chakhmouradian, A.R. (2004) Crystal chemistry and paragenesis of compositionally-unique (A1-, Fe-, Nb-, and Zr-rich) titanite from Africanda, Russia. American Mineralogist, 89, 17521762.
Chakhmouradian, A.R. and Zaitsev, A.N. (2002) Calcite-amphibole-clinopyroxene rock from Afrikanda Complex, Kola peninsula, Russia: mineralogy and possible link to carbonatites. in. Silicate minerals. The Canadian Mineralogist, 40, 13471374.
Chakhmouradian, A.R., Reguir, E.P. and Mitchell, R.H. (2003) Titanite in carbonatitic rocks: Genetic dualism and geochemical significance. Periodico di Mineralogia, 72 Eurocarb Special Issue, 107–113.
Chrosch, J., Bismayer, U. and Salje, E.K.H. (1997) Antiphase boundaries and phase transitions in titanite: An X-ray diffraction study. American Mineralogist, 82, 677681.
Clark, A.M. (1974) A tantalum-rich variety of sphene. Mineralogical Magazine, 39, 605–607.
Delia Ventura, G., Bellatreccia, F. and Williams, C.T. (1999) Zr- and LREE-rich titanite from Tre Croci, Vico Volcanic complex (Latinum, Italy). Mineralogical Magazine, 63, 123–130.
Dowty, E. (1999) Atoms 5.0. By Shape Software, Kingsport, TN 37663, USA, http://shapesoftware.com/
Ghose, S., Yoshiaki, I. and Hatch, D.M. (1991) Paraelectric-antiferroelectric phase transition in titanite, CaTiSiO5. I. A high-temperature X-ray diffraction study of the order parameter and transition mechanism. Physics and Chemistry of Minerals, 17, 591603.
Higgins, J.B. and Ribbe, P.H. (1976) The crystal chemistry and space groups of natural and synthetic titanites. American Mineralogist, 61, 878888.
Hughes, J.M., Bloodaxe, E.S., Hanchar, J.M. and Foord, E.E. (1997) Incorporation of rare earth elements in titanite: Stabilization of the A2/a dimorph by creation of antiphase boundaries. American Mineralogist, 82, 512516.
Kek, S., Aroyo, M., Bismayer, U., Schmidt, C., Eichhorn, K. and Krane, H.G. (1997) The two-step phase transition of titanite, CaTiSiO5: a synchrotron radiation study. Zeitschrift für Kristallographie, 212, 919.
Kern, A.A. and Coelho, A.A. (1998) TOPAS. Allied Publishers Ltd. http://www.bruker-axs.com.
Kunz, M. and Brown, I.D. (1995) Out-of-center distortions around octahedrally coordinated d°-tran-sition metals. Journal of Solid State Chemistry, 115, 395406.
Kunz, M., Xirouchakis, D., Lindsley, D.H. and Hausermann, D. (1996) High-pressure phase transition in titanite (CaTiOSiO4). American Mineralogist, 81, 15271530.
Kunz, M., Arlt, T. and Stolz, J. (2000) In situ powder diffraction study of titanite (CaTiOSiO4) at high pressure and high temperature. American Mineralogist, 85, 14651473.
Makovicky, E. and Balić-Žunić, T. (1998) New measure of distortion for coordination polyhedra. Acta Crystallographica, B54, 766773.
Malcherek, T. (2001) Spontaneous strain in synthetic titanite, CaTiOSiO4 . Mineralogical Magazine, 65, 709715.
Robinson, K., Gibbs, G.V. and Ribbe, P.H. (1971) Quadratic elongation: a quantitative measure of distortion in coordination polyhedra. Science, 172, 567570.
Sahama, Th.G. (1946) On the chemistry of mineral titanite. Bulletin Committee Géologia Finlandie, 24, 138 88120.
Salje, E., Schmidt, C. and Bismayer, U. (1993) Structural phase transitions in titanite, CaTiSiO5: a Raman spectroscopic study. Physics and Chemistry of Minerals, 19, 502506.
Sawka, W.N., Campbell, R.B. and Norrish, K. (1984) Light-rare-earth-element zoning in sphene and allanite during granitoid fractionation. Geology, 12, 131134.
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751767.
Speer, J.A. and Gibbs, G.V. (1976) The crystal structure of synthetic titanite, CaTiOSiO4, and the domain textures of natural titanites. American Mineralogist, 61, 238247.
Taylor, M. and Brown, G.E. (1976) High-temperature structural study of the P2\la -” Alia phase transition in synthetic titanite, CaTiSiO5 . American Mineralogist, 61, 435437.
Tiepolo, M., Oberri, R. and Vanucci, R. (2002)Trace-element incorporation in titanite: constraints from experimentally determined solid/liquid partition coefficients. Chemical Geology, 191, 105119.
Troitzsch, U. and Ellis, D.J. (2002) Thermodynamic properties and stability of AlF-bearing titanite CaTiOSiO4-CaAlFSiO4 . Contributions to Mineralogy and Petrology, 142, 543–563.
Troitzsch, U., Ellis, D.J., Thompson, J. and FitzGerald, J.D. (1999) Crystal structural changes in titanite along the join TiO-AlF. European Journal of Mineralogy, 6, 955965.
van Heurk, C., van Tendeloo, G., Ghose, S. and Amelinckx, S. (1991) Paraelectric-antiferroelectric phase transition in titanite, CaTiSiO5. II. Electron diffraction and electron microscopic studies of the transition dynamics. Physics and Chemistry of Minerals, 17, 604610.
Woolley, A.R., Platt, R.G. and Eby, N. (1992) Niobian titanite from the Ilomba nepheline syenite complex, north Malawi. Mineralogical Magazine, 56, 428430.

Keywords

Crystal structure of a synthetic aluminoan tantalian titanite: a reconnaissance study

  • R. P. Liferovich (a1) and R. H. Mitchell (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed