A ²⁹ Si MAS NMR and IR spectroscopic investigation of synthetic pyrope-grossular garnet solid solutions

Other| August 01, 1995 A 29Si MAS NMR and IR spectroscopic investigation of synthetic pyrope-grossular garnet solid solutions Anne Bosenick; Anne Bosenick Christian-Albrechts-Universitaet zu Kiel, Mineralogisch-Petrographisches Institut, Kiel, Federal Republic of Germany Search for other works by this author on: GSW Google Scholar Charles A. Geiger; Charles A. Geiger Search for other works by this author on: GSW Google Scholar Torsten Schaller; Torsten Schaller Search for other works by this author on: GSW Google Scholar Angelika Sebald Angelika Sebald Search for other works by this author on: GSW Google Scholar American Mineralogist (1995) 80 (7-8): 691–704. https://doi.org/10.2138/am-1995-7-806 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Anne Bosenick, Charles A. Geiger, Torsten Schaller, Angelika Sebald; A 29Si MAS NMR and IR spectroscopic investigation of synthetic pyrope-grossular garnet solid solutions. American Mineralogist 1995;; 80 (7-8): 691–704. doi: https://doi.org/10.2138/am-1995-7-806 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract The 29Si MAS NMR spectra of nine pyrope-grossular garnet solid solutions were recorded along with their mid and far infrared spectra. The29Si MAS NMR spectra of pyrope and grossular measured previously show one single resonance at −72.0 and −83.9 ppm, respectively. A maximum of up to 13 resonances were observed in composition Py50Gr50 indicating that 29Si MAS NMR spectroscopy can record both first and second shell do-decahedral interactions in garnet. Complete resonance assignments were done by qualitative crystal chemical considerations combined with the comparison of fitted peak intensities with the calculated probabilities for the various possible localized chemical environments around the Si tetrahedra. The NMR spectra of garnets with compositions Py90Gr10, Py10Gr90, and Py05Gr95 are consistent with a random distribution of the divalent cations Ca and Mg on the triangular dodecahedral sites. Garnets with compositions between 0.15 ≤ XCa ≤ 0.75 show evidence for deviations from random mixing. No overt evidence is found to support a model of local cation order in the most pyrope-rich compositions, which had been proposed on the basis of the asymmetric volumes of mixing along the binary. Powder IR spectra show no additional bands in the solid solutions compared to the end-members, and hence all solid solution compositions are consistent with space group Ia3d. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.