@prefix pubblicazioni: . @prefix unitaDiPersonaleInterno: . @prefix prodotto: . unitaDiPersonaleInterno:MATRICOLA15020 pubblicazioni:autoreCNRDi prodotto:ID29182 . @prefix prodottidellaricerca: . @prefix istituto: . istituto:CDS043 prodottidellaricerca:prodotto prodotto:ID29182 . @prefix modulo: . modulo:ID3973 prodottidellaricerca:prodotto prodotto:ID29182 . @prefix rdf: . prodotto:ID29182 rdf:type prodotto:TIPO1101 . @prefix retescientifica: . prodotto:ID29182 rdf:type retescientifica:ProdottoDellaRicerca . @prefix rdfs: . prodotto:ID29182 rdfs:label "Short range order minerals: amphiboles. (Articolo in rivista)"@en . @prefix xsd: . prodotto:ID29182 pubblicazioni:anno "2005-01-01T00:00:00+01:00"^^xsd:gYear . @prefix skos: . prodotto:ID29182 skos:altLabel "
Hawthorne F.C.; Della Ventura G.; Oberti R.; Robert J.-L.; Iezzi G. (2005)
Short range order minerals: amphiboles.
in Canadian mineralogist
"^^rdf:HTML ; pubblicazioni:autori "Hawthorne F.C.; Della Ventura G.; Oberti R.; Robert J.-L.; Iezzi G."^^xsd:string ; pubblicazioni:paginaInizio "1895"^^xsd:string ; pubblicazioni:paginaFine "1920"^^xsd:string ; pubblicazioni:numeroVolume "43"^^xsd:string . @prefix ns11: . prodotto:ID29182 pubblicazioni:rivista ns11:ID574211 ; skos:note "ISI Web of Science (WOS)"^^xsd:string ; pubblicazioni:affiliazioni "Frank C. HAWTHORNE\u00A7\nDepartment of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada\nGiancarlo DELLA VENTURA\nDipartimento di Scienze Geologiche, Universit\u00E1 di Roma Tre, Largo San Leonardo Murialdo 1, I-00146 Roma, Italy\nRoberta OBERTI\nCNR-Istituto di Geoscienze e Georisorse, sezione di Pavia, via Ferrata 1, I-27100 Pavia, Italy\nJean-Louis R OBERT\nISTO, UMR 6113, 1A Rue de la Ferollerie, F-45071 Orl\u00E9ans Cedex 2, France\nGianluca I EZZI\nDipartimento di Scienze della Terra, Universit\u00E1 G.D'Annunzio, via dei Vestini 30, I-66100 Chieti Scalo, Italy"^^xsd:string ; pubblicazioni:titolo "Short range order minerals: amphiboles."^^xsd:string ; prodottidellaricerca:abstract "Short-range order involves local clusters of atoms that occur either more or less frequently than predicted by a random\ndistribution. Infrared spectroscopy in the principal (OH)-stretching region is sensitive to such local arrangements, and hence\nthe (OH) group can be used as a local probe of short-range arrangements of atoms. Examination of natural amphiboles of fairly\nsimple composition indicates that the principal (OH)-stretching frequency is sensitive to such local arrangements, generating fine\nstructure that gives information on short-range arrangements. Moreover, the fine structure is sensitive to both nearest-neighbor\nand next-nearest-neighbor arrangements. The short-range arrangements that can occur are constrained by the local version of the\nvalence-matching principle, and this helps in assignment of the bands in the fine structure of the corresponding infrared spectra.\nRecent results on synthetic amphiboles illustrate these issues. Monoclinic amphiboles in the systems richterite-pargasite, tremolite-\npargasite and tremolite-hornblende show strong SRO involving T-, C- and A-group cations. Amphiboles involving (OH)-F\nsolid-solution with M (vacancy) at the A site (e.g., tremolite-fluorotremolite) show one-mode behavior, whereas amphiboles with\nNa or K at the A site (e.g., richterite-fluororichterite) show two-mode behavior, indicating that nearest-neighbor arrangements of\natoms couple through an occupied A site, but do not couple through a vacant A site. Furthermore, the relative band intensities in\n(OH)-F amphibole solid-solutions showing two-mode behavior indicate that (OH) and F are completely short-range disordered\nwith respect to each other in the amphibole series examined thus far. Amphiboles in the system pargasite-fluoropargasite show\nstrong SRO of (OH) and F with regard to the cations occupying the associated nearest-neighbor M(1)M(1)M(3) sites: arrangements\ninvolving MgMgAl-(OH) are far more common than arrangements involving MgMgAl-F. Examination of Ti-bearing\nrichteritic amphiboles show that [4]Ti4+ and Si are short-range disordered with regard to each other. Crystal-structure refinement,\nSIMS analysis and local bond-valence requirements suggest that [6]Ti4+ and O(3)O2- are locally associated at adjacent M(1) and\nO(3) sites in (at least some) amphiboles. It is apparent that SRO is very common in monoclinic amphiboles. Although much work\nremains to be done to fully characterize SRO in amphiboles, the general features are already emerging, and local bond-valence\nrequirements seem to be the (principal) factor controlling this type of order. SRO is of significance in that it will affect the stability\nof amphiboles (and other minerals in which it occurs) through its entropy (and enthalpy) effects; the way in which these effects\ncan be formulated for such a complicated case is not yet clear, but what is clear is that future thermodynamic models need to\nconsider SRO in amphiboles and probably in other minerals in which heterovalent substitutions are common."@en ; prodottidellaricerca:prodottoDi modulo:ID3973 , istituto:CDS043 ; pubblicazioni:autoreCNR unitaDiPersonaleInterno:MATRICOLA15020 . @prefix parolechiave: . prodotto:ID29182 parolechiave:insiemeDiParoleChiave . ns11:ID574211 pubblicazioni:rivistaDi prodotto:ID29182 . parolechiave:insiemeDiParoleChiaveDi prodotto:ID29182 .