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TEM imaging of polytypism in pseudowollastonite

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A study of polytypism in synthetic polycrystalline pseudowollastonite has been made using conventional and high resolution transmission electron microscopy (TEM and HRTEM). Three polytypes of 2, 4 and 6-layers coexist in the one sample in the form of lamellae parallel to (001). From the electron microscopy images the lamellae are interpreted as combinations of the stacking fault vectors: 1/3 [010], 1/6 [310] and 1/6 [3\(\bar 1\)0], which are probably all equivalent at high temperatures. The polytype lamellae are stable even after prolonged annealing at high temperatures greater than 1700K. These observations suggest that the most frequently reported 4-layer polytype is not the only high-temperature stable polytype. No evidence of melt is detected in samples annealed in the regime where premelting behaviour of pseudowollastonite has previously been reported (above 1600 K).

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  1. Dornberger-Schiff K (1962) The symmetry and structure of strontium germanate, SrGeO3, as a structure model for α-wollastonite, CaSiO3. Sov Phys Crystallogr Y 6:694–700

  2. Eckersley MC, Gaskell PH, Barnes AC, Chieux P (1988) Structural ordering in a calcium silicate glass. Nature 335:525–527

  3. Gaskell PH, Eckersley MC, Barnes AC, Chieux P (1991) Mediumrange order in the cation distribution of a calcium silicate glass. Nature 350:675–677

  4. Hilmer W (1963) An X-ray investigation of strontium germanate SrGeO3. Sov Phys Crystallogr 7:573–576

  5. Mac Laren AC (1991) Transmission electron microscopy of minerals and rocks. Cambridge University Press, Cambridge

  6. Moir GK, Gard JA, Glasser FP (1975) Crystal chemistry and solid solutions amongst the pseudowollastonite-like polytypes of CaSiO3, SrSiO3 and BaSiO3. Z Kristallogr 141:437–450

  7. Richet P, Bottinga Y (1984) Anorthite, andesine, wollastonite, diopside, cordierite and pyrope: thermodynamics of melting, glass transitions, and properties of the amorphous phases. Earth Planet Sci Lett 67:415–432

  8. Richet P, Fiquet G (1991) High-temperature heat capacity and premelting of minerals in the system MgO-CaO-Al2O3-SiO2. J Geophys Res 96:445–456

  9. Richet P, Ingrin J, Mysen BO, Courtial P, Gillet Ph (1993) Premelting, anharmonicity, and cation disordering in oxide and silicate minerals. Nature (in preparation)

  10. Yamanaka T, Mori H (1980) The structure and polytypes of α-CaSiO3 (Pseudowollastonite). Acta Crystallogr B37:1010–1017

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Ingrin, J. TEM imaging of polytypism in pseudowollastonite. Phys Chem Minerals 20, 56–62 (1993). https://doi.org/10.1007/BF00202250

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  • Microscopy
  • Electron Microscopy
  • Transmission Electron Microscopy
  • High Resolution
  • Mineral Resource