Nomenclature of the garnet supergroup

Abstract

Research Article| April 01, 2013 Nomenclature of the garnet supergroup Edward S. Grew; Edward S. Grew * 1School of Earth and Climate Sciences, University of Maine, Orono, Maine 04469, U.S.A. *Chair, E-mail: [e-mail] Search for other works by this author on: GSW Google Scholar Andrew J. Locock; Andrew J. Locock 2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar Stuart J. Mills; Stuart J. Mills 3Geosciences, Museum Victoria, GPO Box 666, Melbourne 3001, Victoria, Australia Search for other works by this author on: GSW Google Scholar Irina O. Galuskina; Irina O. Galuskina 4Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, University of Silesia, Będzińska 60, 41-200 Sosnowiec, Poland Search for other works by this author on: GSW Google Scholar Evgeny V. Galuskin; Evgeny V. Galuskin 4Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, University of Silesia, Będzińska 60, 41-200 Sosnowiec, Poland Search for other works by this author on: GSW Google Scholar Ulf Hålenius Ulf Hålenius 5Swedish Museum of Natural History, Department of Mineralogy, P.O. Box 50 007, 104 05 Stockholm, Sweden Search for other works by this author on: GSW Google Scholar Author and Article Information Edward S. Grew * 1School of Earth and Climate Sciences, University of Maine, Orono, Maine 04469, U.S.A. Andrew J. Locock 2Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada Stuart J. Mills 3Geosciences, Museum Victoria, GPO Box 666, Melbourne 3001, Victoria, Australia Irina O. Galuskina 4Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, University of Silesia, Będzińska 60, 41-200 Sosnowiec, Poland Evgeny V. Galuskin 4Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, University of Silesia, Będzińska 60, 41-200 Sosnowiec, Poland Ulf Hålenius 5Swedish Museum of Natural History, Department of Mineralogy, P.O. Box 50 007, 104 05 Stockholm, Sweden *Chair, E-mail: [e-mail] Publisher: Mineralogical Society of America Received: 18 Apr 2012 Accepted: 16 Nov 2012 First Online: 02 Mar 2017 Online ISSN: 1945-3027 Print ISSN: 0003-004X © 2013 Mineralogical Society of America American Mineralogist (2013) 98 (4): 785–811. https://doi.org/10.2138/am.2013.4201 Article history Received: 18 Apr 2012 Accepted: 16 Nov 2012 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Edward S. Grew, Andrew J. Locock, Stuart J. Mills, Irina O. Galuskina, Evgeny V. Galuskin, Ulf Hålenius; Nomenclature of the garnet supergroup. American Mineralogist 2013;; 98 (4): 785–811. doi: https://doi.org/10.2138/am.2013.4201 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 garnet supergroup includes all minerals isostructural with garnet regardless of what elements occupy the four atomic sites, i.e., the supergroup includes several chemical classes. There are presently 32 approved species, with an additional 5 possible species needing further study to be approved. The general formula for the garnet supergroup minerals is {X3}[Y2](Z3)ϕ12, where X, Y, and Z refer to dodecahedral, octahedral, and tetrahedral sites, respectively, and ϕ is O, OH, or F. Most garnets are cubic, space group Ia3̄d (no. 230), but two OH-bearing species (henritermierite and holtstamite) have tetragonal symmetry, space group, I41/acd (no. 142), and their X, Z, and ϕ sites are split into more symmetrically unique atomic positions. Total charge at the Z site and symmetry are criteria for distinguishing groups, whereas the dominant-constituent and dominant-valency rules are critical in identifying species. Twenty-nine species belong to one of five groups: the tetragonal henritermierite group and the isometric bitikleite, schorlomite, garnet, and berzeliite groups with a total charge at Z of 8 (silicate), 9 (oxide), 10 (silicate), 12 (silicate), and 15 (vanadate, arsenate), respectively. Three species are single representatives of potential groups in which Z is vacant or occupied by monovalent (halide, hydroxide) or divalent cations (oxide). We recommend that suffixes (other than Levinson modifiers) not be used in naming minerals in the garnet supergroup. Existing names with suffixes have been replaced with new root names where necessary: bitikleite-(SnAl) to bitikleite, bitikleite-(SnFe) to dzhuluite, bitikleite-(ZrFe) to usturite, and elbrusite-(Zr) to elbrusite. The name hibschite has been discredited in favor of grossular as Si is the dominant cation at the Z site. Twenty-one end-members have been reported as subordinate components in minerals of the garnet supergroup of which six have been reported in amounts up to 20 mol% or more, and, thus, there is potential for more species to be discovered in the garnet supergroup. The nomenclature outlined in this report has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (Voting Proposal 11-D). You do not have access to this content, please speak to your institutional administrator if you feel you should have access.