Research output: Contribution to journal › Article › peer-review
Ion substitutions and structural adjustment in Cr-bearing tourmalines. / Vereshchagin, O.S.; Rozhdestvenskaya, I.V.; Frank-Kamenetskaya, O.V.; Zolotarev, A.A.
In: European Journal of Mineralogy, Vol. 26, No. 2, 2014, p. 309-321.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Ion substitutions and structural adjustment in Cr-bearing tourmalines
AU - Vereshchagin, O.S.
AU - Rozhdestvenskaya, I.V.
AU - Frank-Kamenetskaya, O.V.
AU - Zolotarev, A.A.
PY - 2014
Y1 - 2014
N2 - The geological settings of Cr-bearing tourmaline occurrences are reviewed and the crystal chemistry of Cr-bearing tourmalines is analysed on the basis of new X-ray single-crystal structure refinements (R0.019–0.025) of three crystals from the Ural deposits (Cr2O3 content ∼6 wt.%) and one from Umba Valley, Tanzania (∼1 wt.% Cr2O3) and published data (13 structures) on tourmalines from different deposits with Cr content up to 36 oxide wt.%. The boundary between the ordered and the disordered distribution of Cr between Y and Z octahedral sites is determined near 1.03 ± 0.27 Cr apfu and relationships between Cr content and structural parameters (unit-cell parameters, octahedral bond-lengths, charge of Y and Z sites and polyhedral deformation) are established. An increasing Cr content in tourmaline causes an increase of both lattice parameters, of and bond-lengths and a regular variation of the charge of the Y and Z octahedra. In general, the structure becomes less deformed by reducing the distortion of the octahe
AB - The geological settings of Cr-bearing tourmaline occurrences are reviewed and the crystal chemistry of Cr-bearing tourmalines is analysed on the basis of new X-ray single-crystal structure refinements (R0.019–0.025) of three crystals from the Ural deposits (Cr2O3 content ∼6 wt.%) and one from Umba Valley, Tanzania (∼1 wt.% Cr2O3) and published data (13 structures) on tourmalines from different deposits with Cr content up to 36 oxide wt.%. The boundary between the ordered and the disordered distribution of Cr between Y and Z octahedral sites is determined near 1.03 ± 0.27 Cr apfu and relationships between Cr content and structural parameters (unit-cell parameters, octahedral bond-lengths, charge of Y and Z sites and polyhedral deformation) are established. An increasing Cr content in tourmaline causes an increase of both lattice parameters, of and bond-lengths and a regular variation of the charge of the Y and Z octahedra. In general, the structure becomes less deformed by reducing the distortion of the octahe
U2 - 10.1127/0935-1221/2014/0026-2372
DO - 10.1127/0935-1221/2014/0026-2372
M3 - Article
VL - 26
SP - 309
EP - 321
JO - European Journal of Mineralogy
JF - European Journal of Mineralogy
SN - 0935-1221
IS - 2
ER -
ID: 7002442