Startseite Letter. A new high-pressure CaGe2O5 polymorph with 5- and 6-coordinated germanium
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Letter. A new high-pressure CaGe2O5 polymorph with 5- and 6-coordinated germanium

  • Péter Németh EMAIL logo , Kurt Leinenweber , Thomas L. Groy und Peter R. Buseck
Veröffentlicht/Copyright: 1. April 2015
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American Mineralogist
Aus der Zeitschrift American Mineralogist Band 92 Heft 2-3

Abstract

We discovered a new CaGe2O5 polymorph in high-pressure experiments (above 8 GPa). The phase is orthorhombic, space group Pbam, with a = 7.306(2), b = 8.268(2), c = 5.714(1) Å, V = 345.2(1) Å3, and Z = 4. The new phase, which we call post-titanite CaGe2O5, is the high-pressure polymorph of titanite CaGe2O5. The structure of this new polymorph is based on a network of 5- and 6-coordinated Ge polyhedra and 8-coordinated Ca atoms. Following the germanate analog to silicate, post-titanite CaSi2O5 could be expected to form at high-pressure conditions and thus might exist in Earthʼs mantle.

Keywords : CaGe2O5 polymorph; post-titanite; 5- and 6-coordinated Ge; Earthʼs mantle
Received: 2006-8-8
Accepted: 2006-9-25
Published Online: 2015-4-1
Published in Print: 2007-2-1

© 2015 by Walter de Gruyter Berlin/Boston

Artikel in diesem Heft

  1. Combined cathodoluminescence hyperspectral imaging and wavelength dispersive X-ray analysis of minerals
  2. Identification of cathodoluminescence activators in zoned alkali feldspars by hyperspectral imaging and electron-probe microanalysis
  3. Ionoluminescence of leucophanite
  4. Digital near-infrared (NIR) cathodoluminescence (CL) imaging and image processing
  5. Significance of aluminum phosphate-sulfate minerals associated with U unconformity-type deposits: The Athabasca basin, Canada
  6. Hardness, toughness, and modulus of some common metamorphic minerals
  7. Diffusion compensation for argon, hydrogen, lead, and strontium in minerals: Empirical relationships to crystal chemistry
  8. Elastic anomalies accompanying phase transitions in (Ca,Sr)TiO3 perovskites: Part I. Landau theory and a calibration for SrTiO3
  9. Elastic anomalies accompanying phase transitions in (Ca,Sr)TiO3 perovskites: Part II. Calibration for the effects of composition and pressur
  10. Elastic anomalies accompanying phase transitions in (Ca,Sr)TiO3 perovskites: Part III. Experimental investigation of polycrystalline samples
  11. Patterns in the compositions of oxysalt and sulfosalt minerals, and the paradoxical nature of quartz
  12. Effect of variable carbonate concentration on the solidus of mantle peridotite
  13. Time-resolved structural analysis of K- and Ba-exchange reactions with synthetic Na-birnessite using synchrotron X-ray diffraction
  14. Heat capacity of synthetic hydrous Mg-cordierite at low temperatures: Thermodynamic properties and the behavior of the H2O molecule in selected hydrous micro and nanoporous silicates
  15. Organic anions in layered double hydroxides: An experimental investigation of citrate hydrotalcite
  16. The 6H-SiC structure model: Further refinement from SCXRD data from a terrestrial moissanite
  17. Cobalt incorporation in mullite
  18. Thermal expansion between 480 and 940 °C of Cr-doped mullites derived from single-phase precursors
  19. Armbrusterite, K5Na6Mn3+Mn2+14[Si9O22]4(OH)10·4H2O, a new Mn hydrous heterophyllosilicate from the Khibiny alkaline massif, Kola Peninsula, Russia
  20. Letter. An empirical scaling model for averaging elastic properties including interfacial effects
  21. Letter. Optical absorption spectra of ferropericlase to 84 GPa
  22. Letter. The acoustic emissions signature of a pressure-induced polytypic transformation in chlorite
  23. Letter. A new high-pressure CaGe2O5 polymorph with 5- and 6-coordinated germanium
  24. Letter. Terrestrial analogs of martian jarosites: Major, minor element systematics and Na-K zoning in selected samples
https://doi.org/10.2138/am.2007.2411
Schlagwörter für diesen Artikel
CaGe2O5 polymorph; post-titanite; 5- and 6-coordinated Ge; Earthʼs mantle

Artikel in diesem Heft

  1. Combined cathodoluminescence hyperspectral imaging and wavelength dispersive X-ray analysis of minerals
  2. Identification of cathodoluminescence activators in zoned alkali feldspars by hyperspectral imaging and electron-probe microanalysis
  3. Ionoluminescence of leucophanite
  4. Digital near-infrared (NIR) cathodoluminescence (CL) imaging and image processing
  5. Significance of aluminum phosphate-sulfate minerals associated with U unconformity-type deposits: The Athabasca basin, Canada
  6. Hardness, toughness, and modulus of some common metamorphic minerals
  7. Diffusion compensation for argon, hydrogen, lead, and strontium in minerals: Empirical relationships to crystal chemistry
  8. Elastic anomalies accompanying phase transitions in (Ca,Sr)TiO3 perovskites: Part I. Landau theory and a calibration for SrTiO3
  9. Elastic anomalies accompanying phase transitions in (Ca,Sr)TiO3 perovskites: Part II. Calibration for the effects of composition and pressur
  10. Elastic anomalies accompanying phase transitions in (Ca,Sr)TiO3 perovskites: Part III. Experimental investigation of polycrystalline samples
  11. Patterns in the compositions of oxysalt and sulfosalt minerals, and the paradoxical nature of quartz
  12. Effect of variable carbonate concentration on the solidus of mantle peridotite
  13. Time-resolved structural analysis of K- and Ba-exchange reactions with synthetic Na-birnessite using synchrotron X-ray diffraction
  14. Heat capacity of synthetic hydrous Mg-cordierite at low temperatures: Thermodynamic properties and the behavior of the H2O molecule in selected hydrous micro and nanoporous silicates
  15. Organic anions in layered double hydroxides: An experimental investigation of citrate hydrotalcite
  16. The 6H-SiC structure model: Further refinement from SCXRD data from a terrestrial moissanite
  17. Cobalt incorporation in mullite
  18. Thermal expansion between 480 and 940 °C of Cr-doped mullites derived from single-phase precursors
  19. Armbrusterite, K5Na6Mn3+Mn2+14[Si9O22]4(OH)10·4H2O, a new Mn hydrous heterophyllosilicate from the Khibiny alkaline massif, Kola Peninsula, Russia
  20. Letter. An empirical scaling model for averaging elastic properties including interfacial effects
  21. Letter. Optical absorption spectra of ferropericlase to 84 GPa
  22. Letter. The acoustic emissions signature of a pressure-induced polytypic transformation in chlorite
  23. Letter. A new high-pressure CaGe2O5 polymorph with 5- and 6-coordinated germanium
  24. Letter. Terrestrial analogs of martian jarosites: Major, minor element systematics and Na-K zoning in selected samples
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