Szczegóły publikacji
Opis bibliograficzny
Mg-enriched erythrite from Bou Azzer, Anti-Atlas Mountains, Morocco: geochemical and spectroscopic characteristics / Magdalena DUMAŃSKA-SŁOWIK, Adam PIECZKA, Lucyna NATKANIEC-NOWAK, Piotr Kunecki, Adam GAWEŁ, Wiesław HEFLIK, Wojciech SMOLIŃSKI, Gabriela KOZUB-BUDZYŃ // Mineralogy and Petrology ; ISSN 0930-0708. — 2018 — vol. 112 iss. 3, s. 381–392. — Bibliogr. s. 391–392, Abstr. — Publikacja dostępna online od: 2017-11-10
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Dane bibliometryczne
| ID BaDAP | 116806 |
|---|---|
| Data dodania do BaDAP | 2018-09-27 |
| Tekst źródłowy | URL |
| DOI | 10.1007/s00710-017-0545-8 |
| Rok publikacji | 2018 |
| Typ publikacji | artykuł w czasopiśmie |
| Otwarty dostęp |  |
| Creative Commons | |
| Czasopismo/seria | Mineralogy and Petrology |
Abstract
Supergene Mg-enriched erythrite, with an average composition (Co2.25Mg0.58Ni0.14Fe0.04Mn0.02 Zn0.02) (As1.97P<0.01O8)·8H2O, accompanied by skutterudite, roselite and alloclasite, was identified in a pneumo-hydrothermal quartz-feldspar-carbonate matrix within the ophiolite sequence of Bou Azzer in Morocco. The unit cell parameters of monoclinic Mg-enriched erythrite [space group C2/m, a = 10.252(2) Å, b = 13.427(3) Å, c = 4.757(3) Å, ß = 105.12(1)°] make the mineral comparable with erythrite from other localities. The composition of the sample represents the solid solution between erythrite, hörnesite and annabergite, that is, the nearest to the endmember erythrite. However, Mg-enriched erythrite forming the crystal exhibits variable compositions, especially in Mg and Co contents, with Mg increasing from 0.32 up to 1.39 apfu, and Co decreasing from 2.53 to 1.50 apfu, which manifests in the fine compositional oscillatory zoning. It is the highest content of Mg in erythrite structure reported so far. The most intensive Raman active ν3 and ν1 bands, recorded for the crystal’s zones with maximum Mg contents, occur at 865 and 800 cm− 1 and are shifted towards higher wavenumbers, where normally hörnesite Raman bands appear. The characteristic oscillatory zoning texture results from varying contents of main and trace elements mobilized from the host ores (Co arsenides, mainly skutterudite) and rock-forming minerals (among others, dolomite) by the solutions in the oxidation zone of the ore deposits. The heating of the Mg-enriched erythrite up to 1000 °C leads to the crystallization of the water-free (Co,Mg)3(AsO4)2 phase.