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Spectroscopy of the cation distribution in the schorlomite species of garnet

1995; Mineralogical Society of America; Volume: 80; Issue: 1-2 Linguagem: Inglês

10.2138/am-1995-1-204

1945-3027

Andrew J. Locock, Robert W. Luth, Ronald G. Cavell, Dorian G. W. Smith, M. John M. Duke,

Geological and Geochemical Analysis

Other| February 01, 1995 Spectroscopy of the cation distribution in the schorlomite species of garnet Andrew Locock; Andrew Locock University of Alberta, Department of Geology, Edmonton, AB, Canada Search for other works by this author on: GSW Google Scholar Robert W. Luth; Robert W. Luth Search for other works by this author on: GSW Google Scholar Ronald G. Cavell; Ronald G. Cavell Search for other works by this author on: GSW Google Scholar Dorian G. W. Smith; Dorian G. W. Smith Search for other works by this author on: GSW Google Scholar M. John M. Duke M. John M. Duke Search for other works by this author on: GSW Google Scholar American Mineralogist (1995) 80 (1-2): 27–38. https://doi.org/10.2138/am-1995-1-204 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 Andrew Locock, Robert W. Luth, Ronald G. Cavell, Dorian G. W. Smith, M. John M. Duke; Spectroscopy of the cation distribution in the schorlomite species of garnet. American Mineralogist 1995;; 80 (1-2): 27–38. doi: https://doi.org/10.2138/am-1995-1-204 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract A homogeneous megacryst of schorlomite was investigated to determine the valence states of Fe and Ti and the crystallographic sites occupied by these elements. The chemical composition of the specimen was analyzed by electron microprobe, wet-chemical analysis, FTIR, and INAA. The results from X-ray absorption near-edge structure spectroscopy (XANES) are consistent with exclusively Ti4+ occupying the octahedral site only. The tetrahedral site is deficient in Si and the results of low-temperature 57Fe Mössbauer spectroscopy indicate that the remainder of the site is occupied by Fe3+ and substantial Fe2+. A spin-allowed intensified crystal-field transition of [4]Fe2+ is present in the near-infrared spectrum. The optical absorption spectrum is dominated by an intense band centered at 500 nm with a full width of 8000 cm−1 at half maximum peak height; this band is assigned to an Fe2+-Ti4+ intervalence charge transfer transition between [4]Fe2+ and [6]Ti. The cation site occupancies in this specimen of schorlomite can be expressed by the following formula: {Ca2.866Mg0.080Na0.038Mn0.019}Σ3.003[Ti1.0584+Fe0.6313+Al0.137Fe0.0572+Mg0.055Zr0.039V0.0143+Mn0.013]Σ2.004(Si2.348Fe0.3393+Fe0.3112+[4H]0.005)Σ3.003O12⁠. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not currently have access to this article.