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The crystal structure of dundasite

Published online by Cambridge University Press:  05 July 2018

G. Cocco
Affiliation:
Istituto di Mineralogia, Università di Perugia, Italy
L Fanfani
Affiliation:
Istituto di Mineralogia, Università di Perugia, Italy
A. Nunzi
Affiliation:
Istituto di Mineralogia, Università di Perugia, Italy
P. F. Zanazzi
Affiliation:
Istituto di Mineralogia, Università di Perugia, Italy

Summary

The crystal structure of dundasite from Gonnesa (Italy) was solved by a three-dimensional Patterson function computed using intensity data collected photographically by the Weissenberg method, and refined by successive Fourier maps and least-squares cycles to an R index 0·.066 for 505 independent observed reflections.

The chemical formula resulting from the structural analysis is PbAl2(CO3)2(OH)4·H2O. The mineral is orthorhombic, space group Pbnm, with a 9·08 Å, b 16·37 Å, c 5·62 Å. The dundasite structure consists of a three-dimensional framework of coordination polyhedra around Pb and Al. Pb ions are coordinated by nine oxygen atoms with distances ranging from 2·53 to 2·91 Å. Al ions show the usual octahedral coordination with average Al-O distance 1.90 Å. C-O mean distances are 1·28 and 1·27 Å for the two non-equivalent CO3 groups. The water molecules are not coordinated by the cations.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1972

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References

Albano, (V.), Bellon, (P.L.), Pompa, (F.), and Scatturin, (V.), 1963. La Ricerca Scientifica, 3A, 1067.Google Scholar
Beaumont, (C.) and Guillemin, (C.), 1960. Bull. Soc. franf. Min. Crist. 83, 121.Google Scholar
Cocco, (G.), Fanfani, (L.), and Zanazzi, (P.F.), 1967- Zeits. Krist. 124, 385.CrossRefGoogle Scholar
Cromer, (D.T.), 1965. ,Acta Cryst. 18, 17.CrossRefGoogle Scholar
Cromer, (D.T.), and Weber, (J.T.), 1965. Ibid. IO4. International Tables for X-ray Crystallography, 1962, 3, 202, Birmingham (Kynoch Press).Google Scholar
Jambor, (J.L.), Fong, (D.G.), and Sabina, (A.P.), 1969 . Canad. Min. 10, 84.Google Scholar
McLEAN, (W.J.) and Anthony, (J.W.), 1970. Amer. Min. 55, 1103.Google Scholar
Petterd, (W.F.), 1893- Papers Proc. Roy. Soc. Tasmania, 26.Google Scholar
Prior, (G.T.), 1906. Min. Mag. 14, 167.Google Scholar