Raman spectroscopic quantification of tetrahedral boron in synthetic aluminum-rich tourmaline
- The Raman spectra of five B-[4]-bearing tourmalines of different composition synthesized at 700 degrees C/4.0 GPa (including first-time synthesis of Na-Li-B-[4]-tourmaline, Ca-Li-B-[4]-tourmaline, and Ca-bearing square-B-[4]-tourmaline) reveal a strong correlation between the tetrahedral boron content and the summed relative intensity of all OH-stretching bands between 3300-3430 cm(-1). The band shift to low wavenumbers is explained by strong O3-H center dot center dot center dot O5 hydrogen bridge bonding. Applying the regression equation to natural B-[4]-bearing tourmaline from the Koralpe (Austria) reproduces the EMPA-derived value perfectly [EMPA: 0.67(12) B-[4] pfu vs. Raman: 0.66(13) B-[4] pfu]. This demonstrates that Raman spectroscopy provides a fast and easy-to-use tool for the quantification of tetrahedral boron in tourmaline. The knowledge of the amount of tetrahedral boron in tourmaline has important implications for the better understanding and modeling of B-isotope fractionation between tourmaline and fluid/melt, widelyThe Raman spectra of five B-[4]-bearing tourmalines of different composition synthesized at 700 degrees C/4.0 GPa (including first-time synthesis of Na-Li-B-[4]-tourmaline, Ca-Li-B-[4]-tourmaline, and Ca-bearing square-B-[4]-tourmaline) reveal a strong correlation between the tetrahedral boron content and the summed relative intensity of all OH-stretching bands between 3300-3430 cm(-1). The band shift to low wavenumbers is explained by strong O3-H center dot center dot center dot O5 hydrogen bridge bonding. Applying the regression equation to natural B-[4]-bearing tourmaline from the Koralpe (Austria) reproduces the EMPA-derived value perfectly [EMPA: 0.67(12) B-[4] pfu vs. Raman: 0.66(13) B-[4] pfu]. This demonstrates that Raman spectroscopy provides a fast and easy-to-use tool for the quantification of tetrahedral boron in tourmaline. The knowledge of the amount of tetrahedral boron in tourmaline has important implications for the better understanding and modeling of B-isotope fractionation between tourmaline and fluid/melt, widely used as a tracer of mass transfer processes.…
| Author details: | Martin KutzschbachORCiDGND, Bernd WunderGND, Iris WannhoffORCiDGND, Franziska Daniela Helena WilkeORCiDGND, Frédéric Couffignal, Alexander RochollORCiD |
|---|---|
| DOI: | https://doi.org/10.2138/am-2021-7758 |
| ISSN: | 0003-004X |
| ISSN: | 1945-3027 |
| Title of parent work (English): | American mineralogist : an international journal of earth and planetary materials |
| Publisher: | Mineralogical Society of America |
| Place of publishing: | Washington, DC [u.a.] |
| Publication type: | Article |
| Language: | English |
| Date of first publication: | 2021/05/27 |
| Publication year: | 2021 |
| Release date: | 2024/07/10 |
| Tag: | Beryllium and Boron: Quintessentially Crustal; Lithium; Raman; SIMS; Tourmaline; high pressure; synthesis; tetrahedral boron |
| Volume: | 106 |
| Issue: | 6 |
| Number of pages: | 11 |
| First page: | 872 |
| Last Page: | 882 |
| Funding institution: | Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [Fr 557/31-1, HE 2015/16-1] |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
| Peer review: | Referiert |
| Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |
