Tourmaline of the elbaite-schorl series from the Himalaya Mine, Mesa Grande, California: A detailed investigation
- Author(s)
- Andreas Ertl, George R. Rossman, John M. Hughes, David London, Ying Wang, Julie A. O'Leary, M. Darby Dyar, Stefan Prowatke, Thomas Ludwig, Ekkehart Tillmanns
- Abstract
Chemical, structural, infrared, optical, and Mössbauer spectroscopic data were obtained on tourmalines from gem pockets in the Himalaya mine, San Diego County, California, including a strongly color-zoned crystal. Calcium and Li abundances increase from core to rim, whereas Mn2+ and F increase, reach a maximum, and then decrease. Upon initiation of crystallization of lepidolite, F contents in tourmaline decrease. The black core is a Mn-bearing "oxy-schorl." The grayish-yellow, intermediate zone is Mn-rich "fluor-elbaite" that contains a relatively high Mn content with ~6 wt% MnO. The nearly colorless "fluor-elbaite" rim has the highest Li content of all zones. There is an inverse correlation between the lattice parameter a (for values =15.84 Å) and the Li content (r2 = 0.96). Mössbauer studies from the different zones within this crystal show that the Fe3+/Fe(total) ratio increases continuously from the Fe-rich core to the Fe-poor near-rim zone, consistent with increasing oxygen fugacity during pegmatite pocket evolution. There is a high positive correlation between lat¬tice parameter a (for values =15.84 Å) and (Fe2++Mn2+) content in tourmalines from the elbaite-schorl series (r2 = 0.99). Values lower than 15.84 Å for a are likely a consequence of greater [4]B contents in samples that usually have a (Fe2++Mn2+) content of
- Organisation(s)
- Department of Mineralogy and Crystallography
- External organisation(s)
- California Institute of Technology (Caltech), Miami University, University of Oklahoma, University of Heidelberg, Mount Holyoke College
- Journal
- American Mineralogist: an international journal of earth and planetary materials
- Volume
- 95
- Pages
- 24-40
- No. of pages
- 17
- ISSN
- 0003-004X
- DOI
- https://doi.org/10.2138/am.2010.3271
- Publication date
- 2010
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105113 Crystallography, 105116 Mineralogy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/ef47d286-1556-46af-aec0-88bf342b1c74