Cu- and Mn-bearing tourmalines from Brazil and Mozambique: crystal structures, chemistry and correlations
- Author(s)
- Andreas Ertl, Gerald Giester, U. Schüssler, H. Brätz, M Okrusch, Ekkehart Tillmanns
- Abstract
Cu- and Mn-bearing tourmalines from Brazil and Mozambique were characterised chemically (EMPA and LA-ICP-MS) and by X-ray single-crystal structure refinement. All these samples are rich in Al, Li and F (fluor-elbaite) and contain significant amounts of CuO (up to ~1.8 wt%) and MnO (up to ~3.5 wt%). Structurally investigated samples show a pronounced positive correlation between the distances and the (Li + Mn2+ + Cu + Fe2+) content (apfu) at this site with R 2 = 0.90. An excellent negative correlation exists between the distances and the Al2O3 content (R 2 = 0.94). The samples at each locality generally show a strong negative correlation between the X-site vacancies and the (MnO + FeO) content. The Mn content in these tourmalines depends on the availability of Mn, on the formation temperature, as well as on stereochemical constraints. Because of a very weak correlation between MnO and CuO we believe that the Cu content in tourmaline is essentially dependent on the availability of Cu and on stereochemical constraints.
- Organisation(s)
- Department of Mineralogy and Crystallography
- External organisation(s)
- Julius-Maximilians-Universität Würzburg, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU)
- Journal
- Mineralogy and Petrology
- Volume
- 107
- Pages
- 265-279
- No. of pages
- 15
- ISSN
- 0930-0708
- DOI
- https://doi.org/10.1007/s00710-012-0234-6
- Publication date
- 2013
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105116 Mineralogy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/9cee6524-bbed-4bb5-835f-159324febf78