Details

Autor(en) / Beteiligte

• Ertl, Andreas
• Giester, Gerald
• Schüssler, Ulrich
• Brätz, Helene
• Okrusch, Martin
• Tillmanns, Ekkehart
• Bank, Hermann

Titel

Cu- and Mn-bearing tourmalines from Brazil and Mozambique: crystal structures, chemistry and correlations

Ist Teil von

• Mineralogy and petrology, 2013-04, Vol.107 (2), p.265-279

Ort / Verlag

Vienna: Springer Vienna

Erscheinungsjahr

2013

Link zum Volltext

Quelle

Springer Online Journals Complete

Beschreibungen/Notizen

• 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 < Y -O> distances and the (Li + Mn 2+ + Cu + Fe 2+ ) content (apfu) at this site with R 2 = 0.90. An excellent negative correlation exists between the < Y -O> distances and the Al 2 O 3 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.