Kai Qu, Xianzhang Sima, Xiangping Gu, Weizhi Sun, Guang Fan, Zeqiang Yang, Yanjuan Wang
{"title":"Kenoargentotetrahedrite-(Zn), [Ag6]4+(Cu4Zn2)Sb4S12□, a new member of the tetrahedrite group from the Yindongpo Au deposit, China","authors":"Kai Qu, Xianzhang Sima, Xiangping Gu, Weizhi Sun, Guang Fan, Zeqiang Yang, Yanjuan Wang","doi":"10.5194/ejm-36-397-2024","DOIUrl":null,"url":null,"abstract":"Abstract. The new mineral kenoargentotetrahedrite-(Zn), [Ag6]4+(Cu4Zn2)Sb4S12□, was discovered at the Yindongpo Au deposit, Henan Province, China. It occurs as black metallic anhedral grains or equant crystals up to 40 µm in size. It is opaque in transmitted light and shows a greenish-grey colour in reflected light. Electron microprobe analysis for the studied material gave the empirical formula (on the basis of total cations being equal to 16 atoms per formula unit, apfu): M(2)(Ag3.75Cu2.25)Σ6M(1)[Cu3.90(Zn1.18Fe0.69Cd0.26)Σ2.13]Σ6.03X(3)(Sb3.69As0.27)Σ3.96S(1)S11.94 S(2)□. Kenoargentotetrahedrite-(Zn) is cubic, I4‾3m (no. 217), with a = 10.4624(4) Å, V= 1145.23(13) Å3, and Z= 2. The crystal structure has been refined to a final value of R1= 0.0247 on the basis of 274 independent reflections (Fo > 4σ (Fo)) by using single-crystal X-ray diffraction data. The seven strongest X-ray powder diffraction lines (d in Å (I) (hkl)) are the following: 3.010 (100) (222), 1.844 (30) (044), 2.606 (22) (004), 1.572 (15) (226), 2.046 (9) (134), 7.35 (6) (011), and 1.909 (5) (125). Kenoargentotetrahedrite-(Zn) is isostructural with other keno-member tetrahedrites with the [Ag6]4+ cluster. The structure refinement result confirms the coupling between the site occupancy factor of subvalent hexasilver clusters at the M(2) site and that of the vacancy at the S(2) site. This relationship further substantiates the charge balance substitution mechanism of S-deficiency tetrahedrites: 6M(2)Ag++S(2)S2-= M(2)[Ag6]4++S(2)□.\n","PeriodicalId":11971,"journal":{"name":"European Journal of Mineralogy","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Mineralogy","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/ejm-36-397-2024","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MINERALOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Abstract. The new mineral kenoargentotetrahedrite-(Zn), [Ag6]4+(Cu4Zn2)Sb4S12□, was discovered at the Yindongpo Au deposit, Henan Province, China. It occurs as black metallic anhedral grains or equant crystals up to 40 µm in size. It is opaque in transmitted light and shows a greenish-grey colour in reflected light. Electron microprobe analysis for the studied material gave the empirical formula (on the basis of total cations being equal to 16 atoms per formula unit, apfu): M(2)(Ag3.75Cu2.25)Σ6M(1)[Cu3.90(Zn1.18Fe0.69Cd0.26)Σ2.13]Σ6.03X(3)(Sb3.69As0.27)Σ3.96S(1)S11.94 S(2)□. Kenoargentotetrahedrite-(Zn) is cubic, I4‾3m (no. 217), with a = 10.4624(4) Å, V= 1145.23(13) Å3, and Z= 2. The crystal structure has been refined to a final value of R1= 0.0247 on the basis of 274 independent reflections (Fo > 4σ (Fo)) by using single-crystal X-ray diffraction data. The seven strongest X-ray powder diffraction lines (d in Å (I) (hkl)) are the following: 3.010 (100) (222), 1.844 (30) (044), 2.606 (22) (004), 1.572 (15) (226), 2.046 (9) (134), 7.35 (6) (011), and 1.909 (5) (125). Kenoargentotetrahedrite-(Zn) is isostructural with other keno-member tetrahedrites with the [Ag6]4+ cluster. The structure refinement result confirms the coupling between the site occupancy factor of subvalent hexasilver clusters at the M(2) site and that of the vacancy at the S(2) site. This relationship further substantiates the charge balance substitution mechanism of S-deficiency tetrahedrites: 6M(2)Ag++S(2)S2-= M(2)[Ag6]4++S(2)□.
期刊介绍:
EJM was founded to reach a large audience on an international scale and also for achieving closer cooperation of European countries in the publication of scientific results. The founding societies have set themselves the task of publishing a journal of the highest standard open to all scientists performing mineralogical research in the widest sense of the term, all over the world. Contributions will therefore be published primarily in English.
EJM publishes original papers, review articles and letters dealing with the mineralogical sciences s.l., primarily mineralogy, petrology, geochemistry, crystallography and ore deposits, but also biomineralogy, environmental, applied and technical mineralogy. Nevertheless, papers in any related field, including cultural heritage, will be considered.