Raman spectroscopic study of kuranakhite PbMn 4+ Te 6+ O 6 –a rare tellurate mineral

Tellurates are rare minerals as the tellurate anion is easily reduced to the tellurite ion. An example of a tellurate‐containing mineral is kuranakhite. Two bands at 617 and 686 cm −1 are observed and assigned to the Te 6+ O 6 ν 1 symmetric stretching mode. The observation of two bands suggests the non‐equivalence of the Te 6+ O 6 in the structure. The broad band centred at 743 cm −1 is attributed to the Te 6+ O 6 ν 3 antisymmetric stretching mode. Sharp intense bands at 452 and 462 cm −1 are assigned to the Te 6+ O 6 ν 4 bending mode. A comparison of the Raman spectra of kuranakhite with that of tellurate‐containing minerals tlapallite and xocomecatlite is made in this article. Copyright © 2008 John Wiley & Sons, Ltd.