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Transmission electron microscopy and differential thermal studies of lazurite polymorphs

  • Ishmael Hassan EMAIL logo
Published/Copyright: March 25, 2015
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American Mineralogist
From the journal American Mineralogist Volume 85 Issue 10

Abstract

Transmission electron microscopy (TEM) and thermal (DTA-TG) analyses of lazurite, (Na,Ca)8[Al6Si6O24](SO4,S)2, indicate three forms: cubic, modulated, and orthorhombic. Cubic lazurite contains mainly [Na3Ca·SO4]3+ clusters that are disordered together with the O1 and O2 oxygen atoms, and no satellite reflections occur. In the modulated lazurite structure, [Na3Ca·SO4]3+ and [Na3Ca·S]3+ clusters are ordered and possibly cause ordering of the framework oxygen atoms on the O1 and O2 positions and produce satellite reflections. Different ordering of these clusters gives an orthorhombic supercell with parameters of 2d110 × 6d11̄0 × c with respect to the cubic subcell. The DTA-TG study indicates that the orthorhombic to the modulated phase transition occurs at a peak temperature of 489 °C. A single-crystal fragment of lazurite may contain all three phases, as was observed by TEM in this study. Such intergrowths indicate a continuous framework with different regions of the crystal containing different ordering and chemistries. Two new lazurite superstructures were observed with dimensions of 6d110 × 3d001, and 3d112 × 3d1̄11 with respect to the cubic subcell.

Received: 1999-6-15
Accepted: 2000-4-28
Published Online: 2015-3-25
Published in Print: 2000-10-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. Nucleation and growth kinetics of analcime from precursor Na-clinoptilolite
  2. Viscosities of granitic (sensu lato) melts: Influence of the anorthite component
  3. Geochemistry of pyroxene inclusions from the Warrumbungle Volcano, New South Wales, Australia
  4. Supersilicic clinopyroxene and silica exsolution in UHPM eclogite and pelitic gneiss from the Kokchetav massif, Kazakhstan
  5. Experimental study of intracrystalline Fe2+-Mg exchange in three augite crystals: Effect of composition on geothermometric calibration
  6. Transmission electron microscopy and differential thermal studies of lazurite polymorphs
  7. Re-equilibration of glass and CO2 inclusions in xenolith olivine: A TEM study
  8. Origin and structural character of haüyness in spinel dunite xenoliths from La Palma, Canary Islands
  9. Pyrrhotite varieties from the 9.1 km deep borehole of the KTB project
  10. Mineralogy and magnetic behavior of pyrrhotite from a 260 °C section at the KTB drilling site, Germany
  11. Surface defects and self-diffusion on pyrite {100}: An ultra-high vacuum scanning tunneling microscopy and theoretical modeling study
  12. Rare-earth elements in chlorapatite [Ca10(PO4)6Cl2]: Uptake, site preference, and degradation of monoclinic structure
  13. Thermal pressure in MgO and MgSiO3 perovskite at lower mantle conditions
  14. Electron energy-loss spectroscopy of silicate perovskite-magnesiowüstite high-pressure assemblages
  15. Magnesium coordination environments in glasses and minerals: New insight from high-field magnesium-25 MAS NMR
  16. In situ powder diffraction study of titanite (CaTiOSiO4) at high pressure and high temperature
  17. Surinamite: A high-temperature metamorphic beryllosilicate from Lewisian sapphirine-bearing kyanite-orthopyroxene-quartz-potassium feldspar gneiss at South Harris, N.W. Scotland
  18. Single-crystal X-ray diffraction study of FeGeO3 high-P clinopyroxene (C2/c) up to 8.2 GPa
  19. High-pressure Ca4Al6O13: An example of a calcium aluminate with three different types of coordination polyhedra for aluminum
  20. Cation distribution in synthetic zinc ferrite (Zn0.97Fe2.02O4) from in situ high-temperature neutron powder diffraction
  21. Infrared study of OH sites in tourmaline from the elbaite-schorl series
  22. Second occurrence of okayamalite, Ca2SiB2O7: chemical and TEM characterization
  23. Rietveld refinement of okayamalite, Ca2SiB2O7: Structural evidence for the B/Si ordered distribution
  24. Tumchaite Na2(Zr,Sn)Si4O11·2H2O—A new mineral from carbonatites of the Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia
  25. The crystal structure of thornasite, Na12Th3[Si8O19]4(H2O)18: A novel interrupted silicate framework
  26. Symesite, Pb10(SO4)O7Cl4(H2O), a new PbO-related sheet mineral: Description and crystal structure
  27. Na2Ca2(P2O7)F2, the first diphosphate of the cuspidine family
  28. Amphibole asbestos from Libby, Montana: Aspects of nomenclature
  29. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivines—Comment
  30. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivine—Reply
  31. Letter. Fivefold-coordinated aluminum in tectosilicate glasses observed by triple quantum MAS NMR
https://doi.org/10.2138/am-2000-1006

Articles in the same Issue

  1. Nucleation and growth kinetics of analcime from precursor Na-clinoptilolite
  2. Viscosities of granitic (sensu lato) melts: Influence of the anorthite component
  3. Geochemistry of pyroxene inclusions from the Warrumbungle Volcano, New South Wales, Australia
  4. Supersilicic clinopyroxene and silica exsolution in UHPM eclogite and pelitic gneiss from the Kokchetav massif, Kazakhstan
  5. Experimental study of intracrystalline Fe2+-Mg exchange in three augite crystals: Effect of composition on geothermometric calibration
  6. Transmission electron microscopy and differential thermal studies of lazurite polymorphs
  7. Re-equilibration of glass and CO2 inclusions in xenolith olivine: A TEM study
  8. Origin and structural character of haüyness in spinel dunite xenoliths from La Palma, Canary Islands
  9. Pyrrhotite varieties from the 9.1 km deep borehole of the KTB project
  10. Mineralogy and magnetic behavior of pyrrhotite from a 260 °C section at the KTB drilling site, Germany
  11. Surface defects and self-diffusion on pyrite {100}: An ultra-high vacuum scanning tunneling microscopy and theoretical modeling study
  12. Rare-earth elements in chlorapatite [Ca10(PO4)6Cl2]: Uptake, site preference, and degradation of monoclinic structure
  13. Thermal pressure in MgO and MgSiO3 perovskite at lower mantle conditions
  14. Electron energy-loss spectroscopy of silicate perovskite-magnesiowüstite high-pressure assemblages
  15. Magnesium coordination environments in glasses and minerals: New insight from high-field magnesium-25 MAS NMR
  16. In situ powder diffraction study of titanite (CaTiOSiO4) at high pressure and high temperature
  17. Surinamite: A high-temperature metamorphic beryllosilicate from Lewisian sapphirine-bearing kyanite-orthopyroxene-quartz-potassium feldspar gneiss at South Harris, N.W. Scotland
  18. Single-crystal X-ray diffraction study of FeGeO3 high-P clinopyroxene (C2/c) up to 8.2 GPa
  19. High-pressure Ca4Al6O13: An example of a calcium aluminate with three different types of coordination polyhedra for aluminum
  20. Cation distribution in synthetic zinc ferrite (Zn0.97Fe2.02O4) from in situ high-temperature neutron powder diffraction
  21. Infrared study of OH sites in tourmaline from the elbaite-schorl series
  22. Second occurrence of okayamalite, Ca2SiB2O7: chemical and TEM characterization
  23. Rietveld refinement of okayamalite, Ca2SiB2O7: Structural evidence for the B/Si ordered distribution
  24. Tumchaite Na2(Zr,Sn)Si4O11·2H2O—A new mineral from carbonatites of the Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia
  25. The crystal structure of thornasite, Na12Th3[Si8O19]4(H2O)18: A novel interrupted silicate framework
  26. Symesite, Pb10(SO4)O7Cl4(H2O), a new PbO-related sheet mineral: Description and crystal structure
  27. Na2Ca2(P2O7)F2, the first diphosphate of the cuspidine family
  28. Amphibole asbestos from Libby, Montana: Aspects of nomenclature
  29. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivines—Comment
  30. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivine—Reply
  31. Letter. Fivefold-coordinated aluminum in tectosilicate glasses observed by triple quantum MAS NMR
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