Single-crystal IR spectroscopy of grossular-andradite garnets

Other| December 01, 1995 Single-crystal IR spectroscopy of grossular-andradite garnets B. P. McAloon; B. P. McAloon University of California at Davis, Department of Geology, Davis, CA, United States Search for other works by this author on: GSW Google Scholar A. M. Hofmeister A. M. Hofmeister Washington University, United States Search for other works by this author on: GSW Google Scholar American Mineralogist (1995) 80 (11-12): 1145–1156. https://doi.org/10.2138/am-1995-11-1205 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 B. P. McAloon, A. M. Hofmeister; Single-crystal IR spectroscopy of grossular-andradite garnets. American Mineralogist 1995;; 80 (11-12): 1145–1156. doi: https://doi.org/10.2138/am-1995-11-1205 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract Fe3+-Al3+ substitution in the octahedral site of 14 natural garnet samples was investigated through measurement of complete single-crystal infrared (IR) reflectance spectra across the grossular-andradite [Ca3(AlxFe1−x)2Si3O12] binary. Frequencies of all 17 IR-active fundamental modes depend nearly linearly on composition. Two peaks assigned to translations of the octahedral cations against the O framework exhibit two-mode behavior. Observation of similar frequencies for bands involving Al and Fe3+ and of much larger intensities for bands associated with Fe3+ suggests that the Fe-O bond has greater strength, which compensates for the greater mass of Fe. The nearly linear behavior of the modes indicates that mixing should approach ideality for this series, as was previously observed in thermodynamic studies. The existence of ideal mixing suggests that high degrees of ordering are not present, and thus that ordering might not cause the anomalous birefringence associated with this series. 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.