• journal_title：The Canadian Mineralogist
• Contributor：Barbara L. Sherriff ; Elena V. Sokolova ; Yurii K. Kabalov ; David M. Jenkins ; Gerald Kunath-Fandrei ; Steffen Goetz ; Christian Jäger ; Julius Schneider
• Publisher：Mineralogical Association of Canada
• Date：2000-
• Format：text/html
• Language：en
• Identifier：10.2113/gscanmin.38.5.1201
• journal_abbrev：Can Mineral
• issn：0008-4476
• volume：38
• issue：5
• firstpage：1201
• section：Articles

Rietveld structure refinement, ²⁹Si magic angle spinning (MAS) and ²⁷Al satellite transition (SATRAS) NMR spectroscopic data are given for three natural samples of meionite and for synthetic end-member meionite. Trends in structural parameters and NMR spectra are discussed for the solid-solution series from marialite to meionite. The a cell dimension and ²⁷Al SATRAS NMR spectra show a continuous change through the series, whereas the space group, c cell dimension and ²⁹Si MAS NMR spectra show different trends for the three subseries, Si_9.0–8.3, Si_8.3–7.4 and Si_7.4–6.0. Over the interval Si_9.0–8.3, the space group is I4/m, the c cell dimension increases with Al content, and ²⁹Si spectra show multiple well-resolved peaks; the anion site is occupied by Cl⁻, and the T(1) site, by Si. Si–Al order between the T(2) and T(3) sites causes the space group for Si_8.3–7.4 to be P4₂/n and the ²⁹Si MAS NMR spectra to be dominated by Si(1) (3Si1Al) and Si(3) (1Si3Al) peaks. Here, there is a negative correlation between c cell dimension and Al content. Over the interval Si_7.4–6.0, the c cell parameter increases with Al content, the space group is I4/m, and multiple ²⁹Si MAS NMR peaks become broad and poorly resolved. Ca²⁺ continues to replace monovalent cations in the M site, and Al enters both the T(1) and T(2) sites, producing Al–O–Al bonds. In the natural end-member meionite, however, the Al–Si order is found to be 3:1 for T(1) and 3:5 for T(2).