Abstract
Accurate determination of F in minerals is a difficult task even when high F concentrations are present. Fluorine usually is determined by means of electron micro-probe analysis (EMPA) standardized on non-silicate-matrix compounds (e.g., fluorite), and some previous work has revealed the difficulties in determining F at high concentrations such as found in the humite-group minerals. Moreover, when both single-crystal structure refinement (SREF) and EMPA are available for the same crystal, the two estimates do not always agree. On the other hand, the secondary ion mass spectrometry (SIMS) technique is not easily applied at high F concentrations due to the existence of matrix effects related to the chemical composition and structure of the sample as well as to the concentration of the element itself. We tested the agreement among these analytical techniques in the estimation of high F contents and propose an analytical procedure for the analysis of fluorine. Our results indicate that careful selection of working conditions for EMPA of F together with appropriate correction, can yield accurate fluorine concentrations in minerals. Fluorine data extracted from refined site occupancies are systematically overestimated. New accurate working curves have been worked out for SIMS analysis of F taking Si and Mg, in turn, as the reference element for the matrix. Humite-group minerals show SIMS matrix effects on the order of ~10%. In analyzing fluoborite in the most unfavorable cases, the difference in Ion Yield (F/Mg) between “disoriented” humite-group minerals and “oriented” fluoborite samples can reach ~27%. Finally, a lower than expected IY(F/Si) from the F/Si working curve (made with humite minerals) is shown by topaz, which can be ascribed to chemical matrix effects, as well as to the covalent-type bonding between F and the major element in the matrix (Al).
© 2015 by Walter de Gruyter Berlin/Boston
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- Microstructural characterization of metamorphic magnetite crystals with implications for oxygen isotope distribution
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- Effect of alkalis, phosphorus, and water on the surface tension of haplogranite melt
- Direct observation of immiscibility in pyrope-almandine-grossular garnet
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- Estimation and testing of standard molar thermodynamic properties of tourmaline end-members using data of natural samples
- An investigation of matrix effects in the analysis of fluorine in humite-group minerals by EMPA, SIMS, and SREF
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- XAFS study of Cu model compounds and Cu2+ sorption products on amorphous SiO2, γ-Al2O3, and anatase
- Oxidation-reduction mechanism of iron in dioctahedral smectites: I. Crystal chemistry of oxidized reference nontronites
- Oxidation-reduction mechanism of iron in dioctahedral smectites: II. Crystal chemistry of reduced Garfield nontronite
- 15N NMR study of nitrate ion structure and dynamics in hydrotalcite-like compounds
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- A shell model for the simulation of rhombohedral carbonate minerals and their point defects
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Articles in the same Issue
- Eclogite-facies relics and inferred ultrahigh-pressure metamorphism in the North Dabie Complex, central-eastern China
- Application of INVEQ to the geothermobarometry of metamorphic rocks near a kyanite-sillimanite isograd, Mica Creek, British Columbia
- Microstructural characterization of metamorphic magnetite crystals with implications for oxygen isotope distribution
- Coexisting monazite and allanite in peraluminous granitoids of the TribečMountains, Western Carpathians
- Effect of alkalis, phosphorus, and water on the surface tension of haplogranite melt
- Direct observation of immiscibility in pyrope-almandine-grossular garnet
- On the cluster analysis of grains and crystals in rocks
- Experimental approach to constrain second critical end points in fluid/silicate systems: Near-solidus fluids and melts in the system albite-H2O
- Estimation and testing of standard molar thermodynamic properties of tourmaline end-members using data of natural samples
- An investigation of matrix effects in the analysis of fluorine in humite-group minerals by EMPA, SIMS, and SREF
- New data on the crystal-chemistry of fluoborite by means of SREF, SIMS, and EMP analysis
- Effect of aluminum on Ti-coordination in silicate glasses: A XANES study
- XAFS study of Cu model compounds and Cu2+ sorption products on amorphous SiO2, γ-Al2O3, and anatase
- Oxidation-reduction mechanism of iron in dioctahedral smectites: I. Crystal chemistry of oxidized reference nontronites
- Oxidation-reduction mechanism of iron in dioctahedral smectites: II. Crystal chemistry of reduced Garfield nontronite
- 15N NMR study of nitrate ion structure and dynamics in hydrotalcite-like compounds
- 29Si and 27Al MAS-NMR spectroscopy of b-eucryptite (LiAlSiO4): The enthalpy of Si,Al ordering
- The nuclear and magnetic structure of “white rust”—Fe(OH0.86D0.14)2
- In-situ study of the R3̅ to R3̅c phase transition in the ilmenite-hematite solid solution using time-of-flight neutron powder diffraction
- In situ X-ray diffraction investigation of lawsonite and zoisite at high pressures and temperatures
- A shell model for the simulation of rhombohedral carbonate minerals and their point defects
- Optical properties of natural and cation-exchanged heulandite group zeolites
- The crystal structure of gearksutite, CaAlF4(OH)· H2O
- A new anhydrous amphibole from the Eifel region, Germany: Description and crystal structure of obertiite, NaNa2(Mg3Fe3+Ti4+)Si8O22O2
- Kinoshitalite, Ba(Mg)3(Al2Si2)O10(OH,F)2, a brittle mica from a manganese deposit in Oman: Paragenesis and crystal chemistry
- The crystal structure of parisite-(Ce), Ce2CaF2(CO3)3
- High-pressure synthesis of Na2Mg6Si6O18(OH)2—a new hydrous silicate phase isostructural with aenigmatite