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Mechanism of 2/1- to 3/2-mullite transformation at 1650 °C

  • Martin Schmücker EMAIL logo , Bernd Hildmann and Hartmut Schneider
Published/Copyright: March 28, 2015
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American Mineralogist
From the journal American Mineralogist Volume 87 Issue 8-9

Abstract

The transformation of 2/1-mullite single crystals into stable 3/2-mullite was investigated using reaction couples of 2/1-mullite cut parallel to (001) and silica glass at 1650 °C. A thin layer of 3/2- mullite formed at the surface of the parent 2/1-mullite crystal. Between 3/2- and 2/1-mullite a gradual transition layer of about 1 mm exists. This gradual transition zone and the lack of any interface between the substrate 2/1-mullite and the newly formed 3/2-mullite implies a topotactic transformation mechanism controlled by Al, Si, and O interdiffusion with preservation of the basic crystal structure, especially the AlO6 octahedral chains. The number of O atom vacancies is reduced going from 2/1- to 3/2-mullite, as shown by a gradual decrease of the corresponding superlattice intensities in electron diffraction patterns. As the transformation requires diffusion of Al out of and of Si and O atoms into the 2/1-mullite crystal, a coexisting silicate melt is required as an Al sink and as a source of Si and O atoms.

Received: 2001-10-29
Accepted: 2002-3-21
Published Online: 2015-3-28
Published in Print: 2002-8-1

© 2015 by Walter de Gruyter Berlin/Boston

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  2. Experimental and modeled solubilities of chlorine in aluminosilicate melts, consequences of magma evolution, and implications for exsolution of hydrous chloride melt at Mt. Somma-Vesuvius
  3. Temperature-induced Al -zoning in hornblendes of the Fish Canyon magma, Colorado
  4. Analytical techniques for volatiles: A case study using intermediate (andesitic) glasses
  5. Anomalous optical properties of fibrous tremolite, actinolite, and ferro-actinolite
  6. Protoanthophyllite from three metamorphosed serpentinites
  7. Synthesis of beryllian sapphirine in the system MgO-BeO-Al2O3-SiO2-H2O and comparison with naturally occurring beryllian sapphirine and khmaralite. Part 1: Experiments, TEM, and XRD
  8. Intersite distribution of Fe2+ and Mg in the spinel (sensu stricto)–hercynite series by singlecrystal X-ray diffraction
  9. Structural relationships in (Mn1–xZnx)Mn2O4 (0 ≤ x ≤ 0.26): The “dragging effect” of the tetrahedron on the octahedron
  10. The grid-work texture of authigenic microcrystalline quartz in siliceous crust-type (SCT) mineralized horizons
  11. The crystal structure of vicanite-(Ce), a borosilicate showing an unusual (Si3B3O18)15– polyanion
  12. Submicrometer optical characterization of the grain boundary of optically active Cr3+ doped polycrystalline Al2O3 by near-field spectroscopy
  13. High-temperature, high-pressure optical spectroscopic study of ferric-iron-bearing tourmaline
  14. Infrared and Mössbauer study of Brazilian tourmalines from different geological environments
  15. Isothermal compression of staurolite: A single-crystal study
  16. Equation of state measurements of chlorite, pyrophyllite, and talc
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  19. High-pressure deformation mechanism in scolecite: A combined computationalexperimental study
  20. Far infrared spectra of K+ in dioctahedral and trioctahedral mixed-layer minerals
  21. Ab initio quantum mechanical modeling of infrared vibrational frequencies of the OH group in dioctahedral phyllosilicates. Part I: Methods, results and comparison to experimental data
  22. Ab initio quantum mechanical modeling of infrared vibrational frequencies of the OH group in dioctahedral phyllosilicates. Part II: Main physical factors governing the OH vibrations
  23. On geological interpretations of crystal size distributions: Constant vs. proportionate growth
  24. Allabogdanite, (Fe,Ni)2P, a new mineral from the Onello meteorite: The occurrence and crystal structure
  25. Cristobalite inclusions in the Tatahouine achondrite: Implications for shock conditions
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https://doi.org/10.2138/am-2002-8-918

Articles in the same Issue

  1. Evidence for magmatic vapor deposition of anhydrite prior to the 1991 climactic eruption of Mount Pinatubo, Philippines
  2. Experimental and modeled solubilities of chlorine in aluminosilicate melts, consequences of magma evolution, and implications for exsolution of hydrous chloride melt at Mt. Somma-Vesuvius
  3. Temperature-induced Al -zoning in hornblendes of the Fish Canyon magma, Colorado
  4. Analytical techniques for volatiles: A case study using intermediate (andesitic) glasses
  5. Anomalous optical properties of fibrous tremolite, actinolite, and ferro-actinolite
  6. Protoanthophyllite from three metamorphosed serpentinites
  7. Synthesis of beryllian sapphirine in the system MgO-BeO-Al2O3-SiO2-H2O and comparison with naturally occurring beryllian sapphirine and khmaralite. Part 1: Experiments, TEM, and XRD
  8. Intersite distribution of Fe2+ and Mg in the spinel (sensu stricto)–hercynite series by singlecrystal X-ray diffraction
  9. Structural relationships in (Mn1–xZnx)Mn2O4 (0 ≤ x ≤ 0.26): The “dragging effect” of the tetrahedron on the octahedron
  10. The grid-work texture of authigenic microcrystalline quartz in siliceous crust-type (SCT) mineralized horizons
  11. The crystal structure of vicanite-(Ce), a borosilicate showing an unusual (Si3B3O18)15– polyanion
  12. Submicrometer optical characterization of the grain boundary of optically active Cr3+ doped polycrystalline Al2O3 by near-field spectroscopy
  13. High-temperature, high-pressure optical spectroscopic study of ferric-iron-bearing tourmaline
  14. Infrared and Mössbauer study of Brazilian tourmalines from different geological environments
  15. Isothermal compression of staurolite: A single-crystal study
  16. Equation of state measurements of chlorite, pyrophyllite, and talc
  17. Structure change of Ca1–xSrxTiO3 perovskite with composition and pressure
  18. Mechanism of 2/1- to 3/2-mullite transformation at 1650 °C
  19. High-pressure deformation mechanism in scolecite: A combined computationalexperimental study
  20. Far infrared spectra of K+ in dioctahedral and trioctahedral mixed-layer minerals
  21. Ab initio quantum mechanical modeling of infrared vibrational frequencies of the OH group in dioctahedral phyllosilicates. Part I: Methods, results and comparison to experimental data
  22. Ab initio quantum mechanical modeling of infrared vibrational frequencies of the OH group in dioctahedral phyllosilicates. Part II: Main physical factors governing the OH vibrations
  23. On geological interpretations of crystal size distributions: Constant vs. proportionate growth
  24. Allabogdanite, (Fe,Ni)2P, a new mineral from the Onello meteorite: The occurrence and crystal structure
  25. Cristobalite inclusions in the Tatahouine achondrite: Implications for shock conditions
  26. Letters. Natural occurrence of Fe2SiO4 -spinel in the shocked Umbarger L6 chondrite
  27. Structural refinements of magnesite at very high pressure
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