Home Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3
Article
Licensed
Unlicensed Requires Authentication

Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3

  • Amélie Juhin EMAIL logo , Guillaume Morin , Erik Elkaïm , Daniel J. Frost , Michel Fialin , Farid Juillot and Georges Calas
Published/Copyright: April 2, 2015
Become an author with De Gruyter Brill
Author Information
American Mineralogist
From the journal American Mineralogist Volume 95 Issue 1

Abstract

The crystal structure of a polycrystalline knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3, synthesized at 11 GPa and T = 1500 °C in a multi-anvil press, has been refined from high-resolution synchrotron X-ray powder diffraction data. The structure is cubic, space group Ia3̅d, a = 11.5935(1) Å, V = 1558.27(4) Å3, Dcalc = 3.79 g/cm3. The structural formula indicates that knorringite is susceptible to majorite substitution at these synthesis conditions. The Cr-O distance, 1.959(7) Å, is similar to that in Cr-bearing pyrope Mg3Al2(SiO4)3. This confirms that the magnitude of the Cr-O distance is not responsible for the difference in crystal field splitting values between green knorringite and red Cr-pyrope. A comparison with the structure of other Cr-garnet end-members shows that the Cr-O distance and the [4]Si-O-Cr angle decrease with decreasing synthesis pressure and with increasing X-cation size.

Keywords: Structure refinement; knorringite; XRD; synchrotron powder diffraction; Cr-garnet
Received: 2009-3-14
Accepted: 2009-8-19
Published Online: 2015-4-2
Published in Print: 2010-1-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. Metamorphic ultrahigh-pressure tourmaline: Structure, chemistry, and correlations to P-T conditions
  2. Slavikite—Revision of chemical composition and crystal structure
  3. Anisotropic elasticity of jarosite: A high-P synchrotron XRD study
  4. Tourmaline of the elbaite-schorl series from the Himalaya Mine, Mesa Grande, California: A detailed investigation
  5. Characterization of Al-Si ordering state in an alkali feldspar using atom location by channeling-enhanced microanalysis (ALCHEMI)
  6. The relative stability of stoichiometrically related natural and synthetic double salts
  7. Free energy of formation of zircon based on solubility measurements at high temperature and pressure
  8. Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3
  9. A mineral tracer toward high-resolution dust provenance on the Chinese Loess Plateau: SEM, TEM, and sulfur isotopes of sulfate inclusions in biotite
  10. High-resolution TEM study of jimthompsonite, chesterite, and chain-width disorder in Archean ultramafic rocks from Isua, West Greenland
  11. Retrograde hydration sequence in disordered Mg amphiboles: A TEM investigation
  12. Can electron energy-loss spectroscopy (EELS) be used to quantify hydrogen in minerals from the O K edge?
  13. Texture analysis of a turbostratically disordered Ca-montmorillonite
  14. Packing systematics of the silica polymorphs: The role played by O-O nonbonded interactions in the compression of quartz
  15. Calorimetric study of the surface energy of forsterite
  16. Crystallographic texture of the magnetite-hematite transformation: Evidence for topotactic relationships in natural samples from Quadrilátero Ferrífero, Brazil
  17. Semi-ordered crystalline structure of the Santa Olalla vermiculite inferred from X-ray powder diffraction
  18. Stishovite single-crystal growth and application to silicon self-diffusion measurements
  19. Density of dry peridotite magma at high pressure using an X-ray absorption method
  20. The crystal-structure and vacancy distribution in 6C pyrrhotite
  21. Thermal modification of hematite-ilmenite intergrowths in the Ecstall pluton, British Columbia, Canada
  22. A new Al-rich hydroxylian pseudorutile from Kalimantan, Indonesia
  23. Lapeyreite, Cu3O[AsO3(OH)]2·0.75H2O, a new mineral: Its description and crystal structure
  24. High P-T phase relation of magnesian (Mg0.7Fe0.3) staurolite compositon in the system FeO-MgO-Al2O3-SiO2-H2O: Implications for prograde high-pressure history of ultrahigh-temperature metamorphic rocks
  25. Letter: Hibonite-(Fe), (Fe,Mg)Al12O19, a new alteration mineral from the Allende meteorite
  26. Letter: Ion irradiation of the TiO2 polymorphs and cassiterite
  27. Letter: Corundum + orthopyroxene ± spinel intergrowths in an ultrahigh-temperature Al-Mg granulite from the Southern Marginal Zone, Limpopo Belt, South Africa
  28. Letter: Fe3+ spin transition in CaFe2O4 at high pressure
  29. Density functional theory and Monte Carlo study of octahedral cation ordering of Al/Fe/Mg cations in dioctahedral 2:1 phyllosilicates
https://doi.org/10.2138/am.2010.3243
Keywords for this article
Structure refinement; knorringite; XRD; synchrotron powder diffraction; Cr-garnet

Articles in the same Issue

  1. Metamorphic ultrahigh-pressure tourmaline: Structure, chemistry, and correlations to P-T conditions
  2. Slavikite—Revision of chemical composition and crystal structure
  3. Anisotropic elasticity of jarosite: A high-P synchrotron XRD study
  4. Tourmaline of the elbaite-schorl series from the Himalaya Mine, Mesa Grande, California: A detailed investigation
  5. Characterization of Al-Si ordering state in an alkali feldspar using atom location by channeling-enhanced microanalysis (ALCHEMI)
  6. The relative stability of stoichiometrically related natural and synthetic double salts
  7. Free energy of formation of zircon based on solubility measurements at high temperature and pressure
  8. Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3
  9. A mineral tracer toward high-resolution dust provenance on the Chinese Loess Plateau: SEM, TEM, and sulfur isotopes of sulfate inclusions in biotite
  10. High-resolution TEM study of jimthompsonite, chesterite, and chain-width disorder in Archean ultramafic rocks from Isua, West Greenland
  11. Retrograde hydration sequence in disordered Mg amphiboles: A TEM investigation
  12. Can electron energy-loss spectroscopy (EELS) be used to quantify hydrogen in minerals from the O K edge?
  13. Texture analysis of a turbostratically disordered Ca-montmorillonite
  14. Packing systematics of the silica polymorphs: The role played by O-O nonbonded interactions in the compression of quartz
  15. Calorimetric study of the surface energy of forsterite
  16. Crystallographic texture of the magnetite-hematite transformation: Evidence for topotactic relationships in natural samples from Quadrilátero Ferrífero, Brazil
  17. Semi-ordered crystalline structure of the Santa Olalla vermiculite inferred from X-ray powder diffraction
  18. Stishovite single-crystal growth and application to silicon self-diffusion measurements
  19. Density of dry peridotite magma at high pressure using an X-ray absorption method
  20. The crystal-structure and vacancy distribution in 6C pyrrhotite
  21. Thermal modification of hematite-ilmenite intergrowths in the Ecstall pluton, British Columbia, Canada
  22. A new Al-rich hydroxylian pseudorutile from Kalimantan, Indonesia
  23. Lapeyreite, Cu3O[AsO3(OH)]2·0.75H2O, a new mineral: Its description and crystal structure
  24. High P-T phase relation of magnesian (Mg0.7Fe0.3) staurolite compositon in the system FeO-MgO-Al2O3-SiO2-H2O: Implications for prograde high-pressure history of ultrahigh-temperature metamorphic rocks
  25. Letter: Hibonite-(Fe), (Fe,Mg)Al12O19, a new alteration mineral from the Allende meteorite
  26. Letter: Ion irradiation of the TiO2 polymorphs and cassiterite
  27. Letter: Corundum + orthopyroxene ± spinel intergrowths in an ultrahigh-temperature Al-Mg granulite from the Southern Marginal Zone, Limpopo Belt, South Africa
  28. Letter: Fe3+ spin transition in CaFe2O4 at high pressure
  29. Density functional theory and Monte Carlo study of octahedral cation ordering of Al/Fe/Mg cations in dioctahedral 2:1 phyllosilicates
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 16.9.2025 from https://www.degruyterbrill.com/document/doi/10.2138/am.2010.3243/html
Scroll to top button