Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-10T12:04:31.221Z Has data issue: false hasContentIssue false
  • English
  • Français

The wulfenite—stolzite series: centric or acentric structures?

Published online by Cambridge University Press:  05 July 2018

L. Secco ,
F. Nestola  and
A. Dal Negro
L. Secco*
Affiliation:
Dipartimento di Geoscienze, Università di Padova, Via Giotto 1, I-35137, Padova, Italy
F. Nestola
Affiliation:
Dipartimento di Geoscienze, Università di Padova, Via Giotto 1, I-35137, Padova, Italy
A. Dal Negro
Affiliation:
Dipartimento di Geoscienze, Università di Padova, Via Giotto 1, I-35137, Padova, Italy
*
*E-mail: luciano.secco@unipd.it
Get access Rights & Permissions [Opens in a new window]

Abstract

Three natural crystals of the wulfenite (PbMoO4)—stolzite (PbWO4) series were investigated by single-crystal X-ray diffraction. The results indicate that the symmetry is I41/a from nearly pure wulfenite to intermediate compositions, in contrast to previous work which claimed a symmetry change to 74 symmetry (acentric) for intermediate compositions compared with I41/a (centric space group) for the end-members. The results reported here show that the reflections violating I41/a symmetry observed in this work and in a previous study are related primarily to λ/2 effects, even if Renninger effects are not excluded. Consequently, we find that the I41/a symmetry is retained throughout the wulfenite— stolzite.

Keywords

wulfenitestolzitesingle-crystalX-ray diffraction
Type
Research Article
Information
Mineralogical Magazine , Volume 72 , Issue 4 , August 2008 , pp. 987 - 990
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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

Hibbs, D.E., Jury, CM., Leverett, P., Plimer, I.R. and Williams, P.A. (2000) An explanation for the origin of hemihedrism in wulfenite: the single-structures of I42/a and I4̄ tungstenian wulfenites. Mineralogical Magazine, 64, 1057–1062.CrossRefGoogle Scholar
Ibers, J.A. and Hamilton, W.C. (1974) International Tables for X-ray Crystallography, Kynoch Press, Birmingham, UK.Google Scholar
Kirschbaum, K., Martin, A. and Pinkerton, A. (1997). λ/2 contamination in charge-coupled-device area-detector data. Journal of Applied Crystallography, 30, 514–516.CrossRefGoogle Scholar
Lugli, C, Medici, N. and Saccardo, D. (1999) Natural wulfenite: structural refinement by single- crystal X-ray diffraction. Neues Jahrbuch für Mineralogie-Monatshefte, 6, 281–288.Google Scholar
Moreiras, D.B., Pascual, CM., Granda, S.C., Izard, A.M., Roldán, F.V., Moreno, A.A. and Merchán, J. (1991) La stolzita de La Tala: estructura cristalina, reflectancia, y microdureza Vickers. Boletino Sociedade Espanola, 14, 23–31.Google Scholar
Moreau, J.M., Galez, Ph., Peigneux, J.P. and Korzhik, M.V. (1996) Structural characterization of PbWO4and related new phase Pb7W8O(32-x . Journal of Alloys and Compounds, 238, 46–48.CrossRefGoogle Scholar
Robinson, K., Gibbs, G.V. and Ribbe, P.H. (1971) Quadratic elongation: a quantitative measure of distortion in coordination polyhedra. Science, 172, 567–570.CrossRefGoogle ScholarPubMed
Secco, L., Boscardin, M., Dalla Fontana, G., Martini, B., Pegoraro, S. and Salvetti, A. (2005). Wulfenite e altri minerali di Quittengo, Valle del Cervo, Biella. Rivista Mineralogica Italiana, 3, 170–179.Google Scholar
Sheldrick, G.M. (1997) SHELX, programs for Crystal Structure Analysis. Göttingen, Germany.Google Scholar
Stoe, and Cie, (1999) Crystal Optimisation for Numerical Absorption Correction. Stoe and Cie GmbH, Darmstadt, Germany.Google Scholar