Browsing ELibrary by Author "Oberti R."

Now showing items 1-14 of 14

CHANGES IN THE LOCAL COORDINATION OF TRACE RARE-EARTH ELEMENTS IN GARNETS BY HIGH-ENERGY XAFS: NEW DATA ON DYSPROSIUM

Quartieri S.; Dalconi M.C.; Boscherini F.; Oberti R.; D'Acapito F. (2004)

The site location and local geometry of trace amounts (299 ppm) of dysprosium in a natural melanite garnet from a carbonatitic rock have been studied by high-energy fluorescence-detected X-ray absorption fine-structure ...
CHARACTERIZATION OF TRACE ND AND CE SITE PREFERENCE AND COORDINATION IN NATURAL MELANITES: A COMBINED X-RAY DIFFRACTION AND HIGH-ENERGY XAFS STUDY

Quartieri S.; Boscherini F.; Chaboy J.; Dalconi M.C.; Oberti R.; Zanetti A. (2002)

Natural melanite garnets from carbonatitic rocks have been studied by a multitechnique approach based on both experimental (chemical, diffractometric and spectroscopic) methods and full-multiple scattering calculations of ...
CLINOHOLMQUISTITE DISCREDITED: THE NEW AMPHIBOLE END-MEMBER FLUORO-SODIC-PEDRIZITE

Oberti R.; Cámara F.; Ottolini L. (2005)

Re-examination of holotype “clinoholmquistite”, ideally A□BLi2 C(Mg3Al2) TSi8 O22 X(OH)2 (Ginzburg 1965) from the Tastyg spodumene deposit, Tuva, Siberia, Russia by EMP and SIMS analysis and structure refinement shows that ...
DISTINCT SITE PREFERENCES FOR HEAVY AND LIGHT REE IN AMPHIBOLE AND THE PREDICTION OF AMPH/LDREE

Bottazzi P.; Tiepolo M.; Vannucci R.; Zanetti A.; Brumm R.; Foley S.F.; Oberti R. (1999)

New experimental amphibole/melt partition coefficients from a variety of geologically relevant amphibole (pargasite, kaersutite, and K-richterite) and melt compositions obtained under conditions of interest to upper-mantle ...
FERRI-OTTOLINIITE AND FERRIWHITTAKERITE, TWO NEW END-MEMBERS OF THE NEW GROUP 5 FOR MONOCLINIC AMPHIBOLES

Oberti R.; Cámara F.; Caballero J.M. (2004)

Mineralogical and crystal-chemical descriptions are provided for two end-members of the new Group 5 introduced by Leake et al. (2004) in the nomenclature of amphiboles. This new classification scheme recognizes the occurrence ...
HT-XRD STUDY OF SYNTHETIC FERRIAN MAGNESIAN SPODUMENE: THE EFFECT OF SITE DIMENSION ON THE P21/C→C2/C PHASE TRANSITION

Camara F.; Iezzi G.; Oberti R. (2003)

Ferrian magnesian spodumene was synthesized in the MLFSH system at P=0.4 GPa, T=700 °C, fO2=NNO+2.3. The space group at room T is P21/c [a=9.638(3) A, b=8.709(2) A, c=5.258(2) A, β=109.83(3)°, V=415.2 A3]. The structure ...
INFILTRATION METASOMATISM AT LHERZ AS MONITORED BY SYSTEMATIC ION-MICROPROBE INVESTIGATIONS CLOSE TO A HORNBLENDITE VEIN

Zanetti A.; Vannucci R.; Bottazzi P.; Oberti R.; Ottolini L. (1996)

Systematic investigations (electron- and ion-microprobe, and X-ray structure-refinement) of pyroxenes and amphiboles close to a cm-wide hornblendite vein have been carried out on a composite peridotite sample from the Lherz ...
LITHIUM IN AMPHIBOLES: DETECTION, QUANTIFICATION, AND INCORPORATION MECHANISMS IN THE COMPOSITIONAL SPACE BRIDGING SODIC AND BLI-AMPHIBOLES

Oberti R.; Cámara F.; Ottolini L.; Caballero J.M. (2003)

Lithium is an important constituent in amphiboles, where it can be incorporated up to a limit of three atoms per formula unit (apfu). Lithium can partition itself between the B-group sites (where it occurs at the [6+2] ...
NB AND TA INCORPORATION AND FRACTIONATION IN TITANIAN PARGASITE AND KAERSUTITE: CRYSTAL-CHEMICAL CONSTRAINTS AND IMPLICATIONS FOR NATURAL SYSTEMS

Tiepolo M.; Vannucci R.; Oberti R.; Bottazzi P.; Zanetti A.; Foley S. (2000)

New partition coefficients between liquid and pargasitic/kaersutitic amphiboles (Amph/LDNb,Ta) experimentally determined for Nb and Ta at upper-mantle conditions, combined with single-crystal structure refinement of the ...
SODIC-FERRI-FERROPEDRIZITE AND FERRI-CLINOFERROHOLMQUISTITE: MINERAL DATA AND DEGREE OF ORDER OF THE A-SITE CATIONS IN LI-RICH AMPHIBOLES

Oberti R.; Cámara F.; Ottolini L.; Caballero J.M. (2003)

A systematic examination of metamorphic episyenites in the Pedriza Massif, Sierra de Guadarrama, Spain, allowed detection of two more distinct Li-rich C2/m amphibole species. They can be related to previously described ...
SYNTHESIS, CRYSTAL STRUCTURE AND CRYSTAL CHEMISTRY OF FERRI-CLINOHOLMQUISTITE, □LI2MG3 FE3+2SI8O22(OH)2

Iezzi G.; Cámara F.; Oberti R.; Della Ventura G.; Pedrazzi G.; Robert J.-L. (2004)

This work reports the synthesis of ferri-clinoholmquistite, nominally □Li2(Mg3Fe3+2)Si8O22(OH)2, at varying f O 2 conditions. Amphibole compositions were characterized by X-ray (powder and single-crystal) diffraction, ...
THE P21/M ↔ C2/M PHASE TRANSITION IN SYNTHETIC AMPHIBOLE NA NAMG MG5 SI8 O22 (OH)2: THERMODYNAMIC AND CRYSTAL-CHEMICAL EVALUATION

Cámara F.; Oberti R.; Iezzi G.; Della Ventura G. (2003)

The P21/mC2/m displacive phase transition in the synthetic end-member amphibole Na NaMg Mg5 Si8 O22 (OH)2 has been studied by monitoring changes in unit-cell parameters and the intensities of superlattice reflections at ...
TRACE-ELEMENT INCORPORATION IN TITANITE: CONSTRAINTS FROM EXPERIMENTALLY DETERMINED SOLID/LIQUID PARTITION COEFFICIENTS

Tiepolo M.; Oberti R.; Vannucci R. (2002)

Titanite/liquid partition coefficients for most of the trace elements relevant in petrogenetic studies are provided for titanite-saturated liquids equilibrated at 1.5 GPa and 850 °C starting from lamproitic compositions. ...
TRACE-ELEMENT PARTITIONING IN OLIVINE: MODELLING OF A COMPLETE DATA SET FROM A SYNTHETIC HYDROUS BASANITE MELT

Zanetti A.; Tiepolo M.; Oberti R.; Vannucci R. (2004)

Olivine/liquid partition coefficients for most trace elements relevant in petrogenetic studies are provided for a hydrous basanite melt equilibrated at 1.4 GPa and 1055 °C. The partitioning results determined by a combination ...

Browsing ELibrary by Author "Oberti R."

Browsing ELibrary by Author "Oberti R."

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