Erikjonssonite, (Pb32O21)[(V,Si,Mo,As)O4]4Cl9, a new mineral from the Kombat mine and structural classification of layered lead oxychlorides related to litharge

Chukanov, N.V.; Siidra, O.I.; Polekhovsky, Y.S.; Pekov, I.V.; Varlamov, D.A.; Ermolaeva, V.N.; Virus, A.A.

Авторы: Chukanov N.V., Siidra O.I., Polekhovsky Y.S., Pekov I.V., Varlamov D.A., Ermolaeva V.N., Virus A.A.
Журнал: European Journal of Mineralogy
Том: 31
Номер: 1
Год издания: 2019
Издательство: E. Schweizerbart'sche Verlagsbuchhandlung
Местоположение издательства: Germany
Первая страница: 619
Последняя страница: 628
DOI: 10.1127/ejm/2019/0031-2854
Аннотация: The new lead oxychloride vanadate mineral erikjonssonite was discovered at the abandoned Kombat copper mine, Grootfontein district, Namibia in association with hausmannite, calcite, glaucochroite, baryte, and cerussite. Erikjonssonite forms thick tabular orange-red grains up to 0.30.50.5 mm3. The new mineral is brittle, has Mohs’ hardness of 2½ and an uneven fracture. Distinct cleavage on (010) is observed. Dcalc = 7.967 g/cm3. The reflectance values [Rmax, % / Rmin, % (, nm)] are: 20.4 / 18.9 (470), 19.0 / 17.6 (540), 18.5 / 17.1 (589), 18.0 /16.6 (650). The infrared spectrum shows the absence of H-, C- and B-bearing groups. The chemical composition is (WDS-mode electron microprobe, wt. %): SiO2 0.86, V2O5 1.73, As2O5 0.96, MoO3 1.70, PbO 92.54, Cl 4.15, –O=Cl –0.94, total 101.00. The empirical formula based on 46 apfu O+Cl is Pb31.50(V5+1.45Si1.09Mo6+0.90As5+0.63)4.07Cl8.89O37.11. The simplified formula is (Pb32O21)[(V,Si,Mo,As)O4]4Cl9. The crystal structure has been refined to R = 4.2% based on 7730 independent reflections with I > 2σ(I). Erikjonssonite is monoclinic, C2/c, a = 23.200(5), b = 22.708(5), c = 12.418(3) Å, β = 102.167(4)°, V = 6395(2) Å3, and Z = 4. The structure of erikjonssonite is very similar to that of hereroite: in both minerals two [Pb32O21]22+ oxocentered blocks formed by OPb4 tetrahedra with inserted tetrahedral groups alternate with one chloride sheet. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 3.501 (24) (531, –261), 2.980 (100) (551, –224), 2.794 (45) (–802, –514), 1.990 (24) (–882), 1.977 (21) (–606), 1.762 (20) (715, –8.10.2, 10.6.2), 1.648 (33) (–11.5.5). The mineral is named in honour of the Swedish mineralogist Erik Jonsson (b. 1967). The type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia.
Добавил в систему: Пеков Игорь Викторович

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Erikjonssonite, (Pb32O21)[(V,Si,Mo,As)O4]4Cl9, a new mineral from the Kombat mine and structural classification of layered lead oxychlorides related to lithargeстатья

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