On the symmetry and crystal structure of aguilarite, Ag4SeS
| العنوان: | On the symmetry and crystal structure of aguilarite, Ag4SeS |
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| المؤلفون: | Bindi L. [1, Pingitore N. [3] |
| المصدر: | Mineralogical magazine 77 (2013): 21–31. doi:10.1180/minmag.2013.077.1.03 info:cnr-pdr/source/autori:Bindi L. [1, 2], Pingitore N. [3]/titolo:On the symmetry and crystal structure of aguilarite, Ag4SeS./doi:10.1180%2Fminmag.2013.077.1.03/rivista:Mineralogical magazine (Print)/anno:2013/pagina_da:21/pagina_a:31/intervallo_pagine:21–31/volume:77 |
| بيانات النشر: | Mineralogical Society, 2013. |
| سنة النشر: | 2013 |
| مصطلحات موضوعية: | crystal structure, Aguilarite, aguilarite, Crystal structure, cervelleite, 010402 general chemistry, 010502 geochemistry & geophysics, 01 natural sciences, 0104 chemical sciences, Crystal, chemistry.chemical_compound, Crystallography, chemistry, acanthite, Geochemistry and Petrology, Ag-sulfides, Orthorhombic crystal system, Isostructural, Acanthite, naumannite, Mexico, 0105 earth and related environmental sciences, Monoclinic crystal system, Solid solution |
| الوصف: | An examination of a specimen of aguilarite from the type locality provides new data on the chemistry and structure of this mineral. The chemical formula of the crystal used for the structural study is (Ag3.98 Cu0.02)(Se0.98 S0.84 Te0.18), on the basis of 6 atoms. The mineral was found to be monoclinic, crystallizing in space group P 21/n, with a = 4.2478(2), b = 6.9432(3), c = 8.0042(5) Å , β = 100.103(2)º, V = 232.41(2) Å3 and Z = 4. The crystal structure [refined to R1 = 0.0139 for 958 reflections with I > 2 σ (I)] is topologically identical to that of acanthite, Ag2S. It can be described as a body-centred array of tetrahedrally coordinated X atoms (X = S, Se and Te) with Ag2X3 triangles in planes nearly parallel to (010); the sheets are linked by the Ag1 silver site, which has twofold coordination.Aguilarite is definitively proved to be isostructural with acanthite; it does not have a naumannite-like structure, as previously supposed. Our data support the hypothesis that there are two solid solution series in the system: a monoclinic 'acanthite-like' series (from Ag2S - Ag2S0.4Se0.6), and an orthorhombic 'naumannite-like' series (from Ag2S0.3Se0.7-Ag2Se). This is supported by data gathered on synthetic counterparts. Aguilarite remains as a valid as a mineral species, but it should be described as the Se-analogue of acanthite.In this study we also (1) review the history of the aguilarite; (2) compare properties of synthetic and natural aguilarite; and (3) demonstrate how earlier researchers erred in describing aguilarite as orthorhombic.The Te-bearing composition of the studied aguilarite crystal suggests the possibility of a solid solution with cervelleite (Ag4TeS). |
| تدمد: | 1471-8022 0026-461X |
| DOI: | 10.1180/minmag.2013.077.1.03 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c4152750ef2e8fca5c21aa5da922fad0 https://doi.org/10.1180/minmag.2013.077.1.03 |
| Rights: | RESTRICTED |
| رقم الانضمام: | edsair.doi.dedup.....c4152750ef2e8fca5c21aa5da922fad0 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14718022 0026461X |
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| DOI: | 10.1180/minmag.2013.077.1.03 |