Hostname: page-component-76fb5796d-5g6vh Total loading time: 0 Render date: 2024-04-30T02:27:06.465Z Has data issue: false hasContentIssue false

Transparent bright blue Cu-bearing tourmalines from Paraiba, Brazil

Published online by Cambridge University Press:  05 July 2018

Ulrich Henn
Affiliation:
German foundation for gemstone research, 6580 idar-oberstein, West Germany
Hermann Bank
Affiliation:
German foundation for gemstone research, 6580 idar-oberstein, West Germany
Francisco Hermann Bank
Affiliation:
German foundation for gemstone research, 6580 idar-oberstein, West Germany
Hilmar Von Platen
Affiliation:
Institute for Geosciences, University of Mainz, 6500 Mainz, West Germany
Wolfgang Hofmeister
Affiliation:
Institute for Geosciences, University of Mainz, 6500 Mainz, West Germany

Abstract

Physical, crystal-chemical and absorption spectroscopical properties of blue tourmalines from a new occurrence in the State of Paraiba, Brazil, are described. Refractive indices, birefringence and specific gravity have been determined as ne = 1.615–1.620, no = 1.632–1.640, Δn=−0.017 to −0.020 and 3.04–3.07g/cm3. Microprobe analyses proved the samples to be elbaites, which are relatively Mn-rich and contain 2.1 wt. % CuO and 0.5 wt. % Bi2O3. Lattice constants are ao = 15.854(4) and co = 7.102(1) Å. The blue colour is due to pleochroic absorption bands of Cu2+ and Mn3+ with maxima at 700 and 520 nm respectively.

Type
Mineralogy and Petrology
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Carobbi, G. and Pieruccini, R. (1947) Am. Mineral. 32, 121-30.Google Scholar
Deer, W. A., Howie, R. A., and Zussman, J. (1986) Rock-forming minerals, Vol. IB, 559602. London, Longmans.Google Scholar
Donnay, G. and Barton, R. (1972) Tschermaks Mineral. Petrogr. Mitt. 18, 273-86.CrossRefGoogle Scholar
Epprecht, W. (1953) Schweiz. Mineral. Petrogr. Mitt. 33, 481-505.Google Scholar
Faye, G. H., Manning, P. G., and Nickel, E. H. (1968) Am. Mineral. 53, 1174-201.Google Scholar
Faye, G. H., Manning, P. G., Gosselin, J. R. and Tremblay, R.J. (1974) Can. Mineral. 12, 370-80.Google Scholar
Lehmann, G. (1978) Fortschr. Mineral. 56, 172252.Google Scholar
Manning, P. G. (1969) Can. Mineral. 9, 678-90.Google Scholar
Marfunin, A. S. (1979) Physics of Minerals and Inorganic Materials. Berlin, Springer-Verlag, 352 pp.CrossRefGoogle Scholar
Smith, G. (1978a) Phys. Chem. Minerals, 3, 375-83.CrossRefGoogle Scholar
Smith, G. (1978b) Ibid. 3, 343-73.Google Scholar
Weiner, K. L. and Glas, M. (1985) Was ist Turmalin? Symmetrie—Bauplan—Eigenschafien. München, Sonderheft Turmalin (Mineralientage).Google Scholar
Zemann, J. (1972) Handbook of Geochemistry V. II., Springer-Verlag.Google Scholar