Desymmetrization in eudialyte-group minerals. II. A role of м2-position in ordered р3-model of zr-rich member eudialyte group structure

Cover Page

Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

A re-study of the crystal structure of low-calcium and high-zirconium eudialyte from the Khibiny Mountains of the Kola Peninsula has revealed new features of its structure, namely a decrease in the symmetry of the mineral. The ordering of the Ca, Fe, Mn and Na atoms within the octahedrons of six-membered rings, as well as the Zr and Na atoms in the M2 positions at the centre of the square pyramids, was established within the framework of P3 symmetry. The trigonal cell parameters are a = 14.222(3), c = 30.165(5) Å, and V = 5283.9 Å3. In light of the new data, the low-calcium eudialyte can be classified as either oneillite or raslakite, specifically a high-zirconium variety of the latter. The study of the structure of this mineral in rhombohedral symmetry (space group R3m and R3) and trigonal P3-symmetry has demonstrated that the reduction in structural symmetry of the low-calcium representatives of the eudialyte group allows for the clarification of the ordering of cations occupying pivotal positions within the framework.

Full Text

Restricted Access

About the authors

R. K. Rastsvetaeva

Shubnikov Institute of Crystallography of Kurchatov Complex of Crystallography and Photonics of NRC “Kurchatov Institute”

Author for correspondence.
Email: rast.crys@gmail.com
Russian Federation, Moscow

S. M. Aksenov

Laboratory of Arctic Mineralogy and Material Sciences, Kola Science Center, Russian Academy of Sciences; Geological Institute, Kola Science Center, Russian Academy of Sciences

Email: rast.crys@gmail.com
Russian Federation, Apatity; Apatity

V. M. Gridchina

Shubnikov Institute of Crystallography of Kurchatov Complex of Crystallography and Photonics of NRC “Kurchatov Institute”

Email: rast.crys@gmail.com
Russian Federation, Moscow

N. V. Chukanov

FRC of Problems of Chemical Physics and Medicinal Chemistry, Russian Academy of Sciences

Email: rast.crys@gmail.com
Russian Federation, Chernogolovka

References

  1. Johnsen O., Grice J.D., Gault R.A. // Can. Mineral. 1999. V. 37. P. 1111.
  2. Екименкова И.А., Расцветаева Р.К., Чуканов Н.В. // Докл. РАН. 2000. T. 374. № 3. C. 352.
  3. Расцветаева Р.К., Хомяков А.П. // Кристаллография. 2000. Т. 45. № 4. С. 649.
  4. Расцветаева Р.К., Аксенов С.М., Чуканов Н.В. // Докл. РАН. 2010. Т. 431. № 2. С. 201.
  5. Расцветаева Р.К., Чуканов Н.В., Верин И.А. // Докл. РАН. 2006. Т. 409. № 6. С. 807.
  6. Расцветаева Р.К., Хомяков А.П., Некрасов Ю.В. // Кристаллография. 1999. Т. 44. № 5. С. 824. eLIBRARY ID: 14997806
  7. Расцветаева Р.К., Розенберг К.А., Пеков И.В. и др. // Кристаллография. 2006. Т. 51. № 1. С. 44.
  8. Расцветаева Р.К., Чуканов Н.В. // Зап. Рос. минерал. о-ва. 2011. Ч. 140. № 3. С. 25.
  9. Расцветаева Р.К., Чуканов Н.В., Аксенов С.М. Минералы группы эвдиалита: кристаллохимия, свойства, генезис. Нижний Новгород: Изд-во НГУ, 2012. 229 с.
  10. Расцветаева Р.К., Хомяков А.П. // Кристаллография. 2000. T. 45. № 2. C. 251. eLIBRARY ID: 14997806.
  11. Аксенов С.М., Расцветаева Р.К. // Кристаллография. 2013. Т. 58. № 5. С. 660. https://doi.org/10.7868/S0023476113040024
  12. Андрианов В.И. // Кристаллография. 1987. Т. 32. № 1. С. 228.
  13. Chukanov N.V., Zolotarev A.A., Schäfer Ch. et al. // Mineral. Mag. 2024. Р. 1. https://doi.org/10.1180/mgm.2024.26
  14. Расцветаева Р.К., Аксенов С.М., Гридчина В.М., Чуканов Н.В. // Кристаллография. 2024. Т. 69. № 5. С. 788. https://doi.org/10.31857/S0023476124050047

Supplementary files

Supplementary Files
Action
1. JATS XML
Download
2. Fig. 1. Layered fragment of the structure of a high-zirconium mineral of the eudialyte group. Block isomorphism in the octahedra of six-membered rings and M2-positions with square coordination at the levels z = 0, 0.33 and 0.66, respectively.

Download (249KB)
Indexing metadata

Copyright (c) 2024 Russian Academy of Sciences