Geology of Ore Deposits

, Volume 53, Issue 8, pp 806–817

Chemical composition and species attribution of tourmalines from a rare-metal pegmatite vein with scapolite, Sangilen Upland, Tuva

  • L. G. Kuznetsova
  • A. A. Zolotarev
  • O. V. Frank-Kamenetskaya
  • I. V. Rozhdestvenskaya
  • Yu. M. Bronzova
  • J. Spratte
  • A. Ertl
Article

DOI: 10.1134/S1075701511080095

Cite this article as:
Kuznetsova, L.G., Zolotarev, A.A., Frank-Kamenetskaya, O.V. et al. Geol. Ore Deposits (2011) 53: 806. doi:10.1134/S1075701511080095

Abstract

A detailed study of the chemical composition and substitutions in calcium tourmalines from a scapolite-bearing rare-metal pegmatite vein from the Sol’bel’der River basin has shown that their species attribution is determined by occupancy of octahedral site Y. The composition of the yellow tourmaline most abundant in the central part of the pegmatite bodyis rather constant and characterized by the ideal formula Ca(Mg2Li)Al6(Si6O18)(BO3)3(OH)3F. Variations in the chemical composition of zonal tourmaline crystals from the contact part of the pegmatite are controlled by abrupt change in the chemical medium during their formation. The yellow cores of these crystals are close in composition to tourmaline from the central part of the pegmatite vein. The Mg content abruptly decreases toward the crystal margin: Mg2+ → Fe2+, 2Mg2+ → Li+ + Al3+, and Mg2+ + OH → Al3+ + O2−. The composition of dark green marginal zones in tourmaline is characterized by the ideal formula Ca(Al1.5Li1.5)Al6(Si6O18)(BO3)3 (OH2O)(F). The results indicate specific formation conditions of pegmatite. The crystallochemical formulas of the studied tourmalines allow us to regard them as new mineral species in the tourmaline group.

Copyright information

© Pleiades Publishing, Ltd. 2011

Authors and Affiliations

  • L. G. Kuznetsova
    • 1
  • A. A. Zolotarev
    • 2
  • O. V. Frank-Kamenetskaya
    • 2
  • I. V. Rozhdestvenskaya
    • 2
  • Yu. M. Bronzova
    • 2
  • J. Spratte
    • 3
  • A. Ertl
    • 4
  1. 1.Institute of Geochemistry, Siberian BranchRussian Academy of SciencesIrkutskRussia
  2. 2.St. Petersburg State UniversitySt. PetersburgRussia
  3. 3.Natural History MuseumLondonUK
  4. 4.Institute of Mineralogy and Crystallography, Faculty of Geoscience, Geography, and AstronomyUniversity of ViennaViennaAustria