Ceramics: Contribution of Secondary Ion Mass Spectrometry (SIMS) to the Study of Crystal Chemistry of MICA Minerals

Ottolini, Luisa; Schingaro, Emanuela; Scordari, Fernando

doi:10.1002/9781118180730.ch43

Cited by 3 publications

(3 citation statements)

References 106 publications

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“…The combination of EMP and SCXRD data leads to the structural formulae given in Table 8. They were calculated following the procedure described in Ottolini et al (2012) and Schingaro et al (2013). Note that the formulae of the samples studied are similar to those of the Vesuvius fluorophlogopite from the 1872 eruptions (Balassone et al, 2013), apart from a small tetraferriphlogopite component and a greater variability in VI Fe 3+ content.…”

Section: Crystal Chemistry Of Fluorophlogopitementioning

confidence: 99%

Fluorophlogopite-bearing and carbonate metamorphosed xenoliths from theCampanian Ignimbrite (Fiano, southern Italy): crystal chemical, geochemical and volcanological insights

et al. 2017

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Fluorine-, boron- and magnesium-rich metamorphosed xenoliths occur in the Campanian Ignimbrite deposits at Fiano (southern Italy), at ∼50 km northeast of the sourced volcanic area. These rocks originated from Mesozoic limestones of the Campanian Apennines, embedded in a fluid flow. The Fiano xenoliths studied consist of ten fluorophlogopite-bearing calc-silicate rocks and five carbonate xenoliths, characterized by combining mineralogical analyses with whole-rock and stable isotope data. The micaceous xenoliths are composed of abundant idiomorphic fluorophlogopite, widespread fluorite, F-rich chondrodite, fluoborite, diopside, Fe(Mg)-oxides, calcite, humite, K-bearing fluoro-richterite and grossular. Of the five mica-free xenoliths, two are calcite marbles, containing subordinate fluorite and hematite, and three are weakly metamorphosed carbonates, composed only of calcite. The crystal structure and composition of fluorophlogopite approach that of the end-member. The Fiano xenoliths are enriched in trace elements with respect to the primary limestones. Comparisons between the rare-earth element (REE) patterns of the Fiano xenoliths and those of both Campanian Ignimbrite and Somma-Vesuvius marble and carbonate xenoliths showthat the Fiano pattern overlaps that of Somma-Vesuvius marble and carbonate xenoliths, and reproduces the trend of Campanian Ignimbrite rocks. Values of δ13C and δ18O depict the same trend of depletion in the heavy isotopes observed in the Somma-Vesuvius nodules, and is related to thermometamorphism. Trace-element distribution, paragenesis, stable isotope geochemistry and data modelling point to infiltration of steam enriched in F, B,Mg and As into carbonate rocks at a temperature of ∼300–450°C during the emplacement of the Campanian Ignimbrite.

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Section: Crystal Chemistry Of Fluorophlogopitementioning

confidence: 99%

Fluorophlogopite-bearing and carbonate metamorphosed xenoliths from theCampanian Ignimbrite (Fiano, southern Italy): crystal chemical, geochemical and volcanological insights

et al. 2017

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“…In the case of absence of direct estimation of the above variables the crystal chemical details may be of help: the hydrogen content can be estimated from the c parameter and the Fe 2+ /Fe 3+ ratio the one providing the best agreement between the EPMA-derived and the structure refinementderived mean atomic numbers as well as between calculated and observe bond distances (Ottolini et al, 2012). Structural evidence (i.e., geometrical distortions) of substitution mechanisms can also be employed.…”

Section: Micasmentioning

confidence: 99%

Genetic implications, composition, and structure of trioctahedral micas in xenoliths related to Plinian eruptions from the Somma-Vesuvius volcano (Italy)

Balassone,

Schingaro,

Lacalamita

et al. 2024

American Mineralogist

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“…This indicates that near surface features in our sample are close to the bulk ones and that, thanks to the remarkable intergranular homogeneity (see Table 1), the Fe 3+ /Fe 2+ ratio from one single crystal (this work) is similar to that obtained from many powdered single crystals (Mössbauer analysis). Last but not least, from a crystal-chemical viewpoint, once the water content is given (measured or estimated), if the average Fe 3+ /Fe 2+ were too much different from that of the individual single crystals, a bad agreement between observed and calculated mean atomic numbers at octahedral sites [i.e., the e -(M1+M2+M3) X-ref and e -(M1+M2+ M3) EPMA ] would have to be expected (see Ottolini et al 2012). In our case, the difference between observed and calculated m.a.n.…”

Section: (D)mentioning

confidence: 99%

3T-phlogopite from Kasenyi kamafugite (SW Uganda): EPMA, XPS, FTIR, and SCXRD study

Schingaro

Lacalamita

Scordari

et al. 2013

American Mineralogist

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A 3T mica polytype from Kasenyi (south west Uganda) kamafugite was studied by Electron Probe Microanalysis (EPMA), Single Crystal X-ray Diffraction (SCXRD), micro-Fourier Transform Infrared Spectoscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) in order to characterize its crystal chemistry and the relationships with samples from the same rock but showing different stacking sequence. EPMA data gave: SiO2 = 38.7(2), Al2O3 = 13.08(9), MgO = 20.4(2), TiO2 = 4.8(1), MnO = 0.03(3), FeOtot = 5.51(9), Cr2O3 = 0.90(7), NiO = 0.11(5), SrO = 0.03(3), ZnO = 0.04(3), ZrO2 = 0.01(2), K2O = 9.64(5), Na2O = 0.29(1), BaO = 0.15(5), F = 0.13(5) and Cl = 0.01(1) wt%. The analysed sample may be classified as a Ti-rich, F-poor mica with a composition in the phlogopite- annite join end members. \ud X-ray photoelectron spectroscopy provided Fe2+/Fe3+ and O2- /OH equal to ~ 0.75 and 7.14, respectively, which are in agreement with the results of previous Mössbauer investigation on the BU1 sample and with the structural formula of the studied crystal. Infrared spectra showed, in the OH- stretching region (~ 3740-3600 cm-1 cm-1), a shoulder at ~ 3660 cm-1 which is assigned to MgMgFe3+-OH--K-O2- local configurations. No evidences of vacancy substitutions were observed. \ud Single crystal X-ray refinement using anisotropic displacement parameters was performed in the P3112 space group and converged to R1 = 4.34 and wR2 = 3.33 %. Unit cell parameters are: a = b = 5.3235(3) and c = 30.188(2) Å. Geometrical and chemical considerations point to a disordered cation distribution over T1 and T2 tetrahedral sites, whereas partial cation ordering characterizes the octahedral sites with M1 = M2 ≠ M3. Tetrahedral bond/edge lengths distortion and angle variances parameters evidence more distorted polyhedra in 3T polytype than those found in coexisting 1M and 2M1 polytypes.\ud Finally, the overall crystal chemical features indicates the occurrence in the studied sample of the following substitution mechanisms: tetraferriphlogopite [IVFe3+ IVAl]; Ti-oxy [VIM2+ + 2 (OH)  VITi4+ + 2 (O2–) + H2] and Al, Fe3+, Cr-oxy [VIM2+ + (OH)  VIM3+ + O2– + ½ (H2)]; Al, Fe3+-Tschermak [VIM2+ + IVSi4+  VI(Al3+, Fe3+) + IVAl3+]; XIIK+ + IVAl3+  IVSi4+ + XII

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Ceramics: Contribution of Secondary Ion Mass Spectrometry (SIMS) to the Study of Crystal Chemistry of MICA Minerals

Cited by 3 publications

References 106 publications

Fluorophlogopite-bearing and carbonate metamorphosed xenoliths from theCampanian Ignimbrite (Fiano, southern Italy): crystal chemical, geochemical and volcanological insights

Fluorophlogopite-bearing and carbonate metamorphosed xenoliths from theCampanian Ignimbrite (Fiano, southern Italy): crystal chemical, geochemical and volcanological insights

Genetic implications, composition, and structure of trioctahedral micas in xenoliths related to Plinian eruptions from the Somma-Vesuvius volcano (Italy)

3T-phlogopite from Kasenyi kamafugite (SW Uganda): EPMA, XPS, FTIR, and SCXRD study

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