{"title":"未取代富Sb维京岩Vik40,Ag2.85Pb12.35(Bi9.52Sb1.27)∑=10.80S30的晶体结构:位置群及其与维京岩Vig50,Ag3.5Pb11.0Bi11.5S30结构的比较","authors":"R. Pažout, M. Dušek","doi":"10.3190/jgeosci.329","DOIUrl":null,"url":null,"abstract":"Crystal structure of Sb-rich vikingite with lillianite substitution percentage L % below 50 % from Kutná Hora ore district, Czech Republic, was solved and refined from single-crystal diffraction data to determine the site populations of metal sites concerning a) the decreasing “lillianite“ substitution 2 Pb2+ = Ag+ + Bi; b) Sb content not known in vikingite from other localities throughout the world. Vikingite is monoclinic, C2/m, with a = 13.5394(10), b = 4.0992(3), c = 25.506(3) Å, β = 95.597(8)°, V = 1408.9(2) Å3, Z = 1, Dc = 7.0412 g/cm3. The structural formula derived from the refinement is Ag2.85Pb12.35(Bi9.52Sb1.27)Σ=10.80S30, corresponding to Vik40.0. The structure of vikingite is composed of thinner slabs (4L) of four octahedra Me2–Me1–Me1–Me2 and thicker slabs (7L) of seven octahedra Me4–Me5–Me6–Me7–Me6–Me5–Me4 separated by Pb atoms Me3 in trigonal prismatic coordination. The refinement showed differences between the structures of Vik40 and the previously published structure of Vik50. The drop of L % below 50 % shows most profoundly in the marginal octahedral site Me2 of the thinner 4L slabs, which becomes a Bi–Pb–Ag site with 28.6 % of silver next to 50 % of Bi and 21.4 % of Pb. The central Me1 site from 4L slabs which is almost a pure Bi site in Vik50 (0.97 Bi + 0.3 Ag) becomes a Bi-Pb site with minor Sb (0.54 Bi + 0.06 Sb + 0.40 Pb) in Vik40. The Sb for Bi substitution was found to take place in the semimarginal site Me5 (0.74 Bi + 0.26 Sb) in the thicker 7L slabs, which is a pure Bi site in Sb-free Vik50. Another important change against Vik50 occurs in central octahedral site Me6 (pure Pb site in Vik50), which becomes – despite the decrease in Bi content with decreasing L % – a Pb–Bi mix site. The correctness of the refined structural model was verified and the occupancies of mixed sites were fine-tuned employing charge distribution calculations in program ECoN21. In Vik40 weighted average bond lengths RAV of the marginal sites Me2 and Me4 and of the central site Me1 are significantly larger than in Vik50, reflecting the lower Ag content and the presence of Pb, while the Bi site Me5, which is partly substituted by Sb and the site Me6 with minor Bi at the expense of Pb exhibit adequately shortened RAV values.","PeriodicalId":15957,"journal":{"name":"Journal of Geosciences","volume":" ","pages":""},"PeriodicalIF":1.1000,"publicationDate":"2021-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Crystal structure of undersubstituted Sb-rich vikingite Vik40, Ag2.85Pb12.35(Bi9.52Sb1.27)Σ=10.80S30: site population and comparison with structure of vikingite Vik50, Ag3.5Pb11.0Bi11.5S30\",\"authors\":\"R. Pažout, M. Dušek\",\"doi\":\"10.3190/jgeosci.329\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Crystal structure of Sb-rich vikingite with lillianite substitution percentage L % below 50 % from Kutná Hora ore district, Czech Republic, was solved and refined from single-crystal diffraction data to determine the site populations of metal sites concerning a) the decreasing “lillianite“ substitution 2 Pb2+ = Ag+ + Bi; b) Sb content not known in vikingite from other localities throughout the world. Vikingite is monoclinic, C2/m, with a = 13.5394(10), b = 4.0992(3), c = 25.506(3) Å, β = 95.597(8)°, V = 1408.9(2) Å3, Z = 1, Dc = 7.0412 g/cm3. The structural formula derived from the refinement is Ag2.85Pb12.35(Bi9.52Sb1.27)Σ=10.80S30, corresponding to Vik40.0. The structure of vikingite is composed of thinner slabs (4L) of four octahedra Me2–Me1–Me1–Me2 and thicker slabs (7L) of seven octahedra Me4–Me5–Me6–Me7–Me6–Me5–Me4 separated by Pb atoms Me3 in trigonal prismatic coordination. The refinement showed differences between the structures of Vik40 and the previously published structure of Vik50. The drop of L % below 50 % shows most profoundly in the marginal octahedral site Me2 of the thinner 4L slabs, which becomes a Bi–Pb–Ag site with 28.6 % of silver next to 50 % of Bi and 21.4 % of Pb. The central Me1 site from 4L slabs which is almost a pure Bi site in Vik50 (0.97 Bi + 0.3 Ag) becomes a Bi-Pb site with minor Sb (0.54 Bi + 0.06 Sb + 0.40 Pb) in Vik40. The Sb for Bi substitution was found to take place in the semimarginal site Me5 (0.74 Bi + 0.26 Sb) in the thicker 7L slabs, which is a pure Bi site in Sb-free Vik50. Another important change against Vik50 occurs in central octahedral site Me6 (pure Pb site in Vik50), which becomes – despite the decrease in Bi content with decreasing L % – a Pb–Bi mix site. The correctness of the refined structural model was verified and the occupancies of mixed sites were fine-tuned employing charge distribution calculations in program ECoN21. In Vik40 weighted average bond lengths RAV of the marginal sites Me2 and Me4 and of the central site Me1 are significantly larger than in Vik50, reflecting the lower Ag content and the presence of Pb, while the Bi site Me5, which is partly substituted by Sb and the site Me6 with minor Bi at the expense of Pb exhibit adequately shortened RAV values.\",\"PeriodicalId\":15957,\"journal\":{\"name\":\"Journal of Geosciences\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2021-11-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Geosciences\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.3190/jgeosci.329\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geosciences","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.3190/jgeosci.329","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Crystal structure of undersubstituted Sb-rich vikingite Vik40, Ag2.85Pb12.35(Bi9.52Sb1.27)Σ=10.80S30: site population and comparison with structure of vikingite Vik50, Ag3.5Pb11.0Bi11.5S30
Crystal structure of Sb-rich vikingite with lillianite substitution percentage L % below 50 % from Kutná Hora ore district, Czech Republic, was solved and refined from single-crystal diffraction data to determine the site populations of metal sites concerning a) the decreasing “lillianite“ substitution 2 Pb2+ = Ag+ + Bi; b) Sb content not known in vikingite from other localities throughout the world. Vikingite is monoclinic, C2/m, with a = 13.5394(10), b = 4.0992(3), c = 25.506(3) Å, β = 95.597(8)°, V = 1408.9(2) Å3, Z = 1, Dc = 7.0412 g/cm3. The structural formula derived from the refinement is Ag2.85Pb12.35(Bi9.52Sb1.27)Σ=10.80S30, corresponding to Vik40.0. The structure of vikingite is composed of thinner slabs (4L) of four octahedra Me2–Me1–Me1–Me2 and thicker slabs (7L) of seven octahedra Me4–Me5–Me6–Me7–Me6–Me5–Me4 separated by Pb atoms Me3 in trigonal prismatic coordination. The refinement showed differences between the structures of Vik40 and the previously published structure of Vik50. The drop of L % below 50 % shows most profoundly in the marginal octahedral site Me2 of the thinner 4L slabs, which becomes a Bi–Pb–Ag site with 28.6 % of silver next to 50 % of Bi and 21.4 % of Pb. The central Me1 site from 4L slabs which is almost a pure Bi site in Vik50 (0.97 Bi + 0.3 Ag) becomes a Bi-Pb site with minor Sb (0.54 Bi + 0.06 Sb + 0.40 Pb) in Vik40. The Sb for Bi substitution was found to take place in the semimarginal site Me5 (0.74 Bi + 0.26 Sb) in the thicker 7L slabs, which is a pure Bi site in Sb-free Vik50. Another important change against Vik50 occurs in central octahedral site Me6 (pure Pb site in Vik50), which becomes – despite the decrease in Bi content with decreasing L % – a Pb–Bi mix site. The correctness of the refined structural model was verified and the occupancies of mixed sites were fine-tuned employing charge distribution calculations in program ECoN21. In Vik40 weighted average bond lengths RAV of the marginal sites Me2 and Me4 and of the central site Me1 are significantly larger than in Vik50, reflecting the lower Ag content and the presence of Pb, while the Bi site Me5, which is partly substituted by Sb and the site Me6 with minor Bi at the expense of Pb exhibit adequately shortened RAV values.
期刊介绍:
The Journal of Geosciences is an international peer-reviewed journal published by the Czech Geological Society with support from the Czech Geological Survey. It accepts high-quality original research or review papers dealing with all aspects of the nature and origin of igneous and metamorphic rocks. The Journal focuses, mainly but not exclusively, on:
-Process-oriented regional studies of igneous and metamorphic complexes-
Research in structural geology and tectonics-
Igneous and metamorphic petrology-
Mineral chemistry and mineralogy-
Major- and trace-element geochemistry, isotope geochemistry-
Dating igneous activity and metamorphic events-
Experimental petrology and mineralogy-
Theoretical models of igneous and metamorphic processes-
Mineralizing processes and mineral deposits.
All the papers are written in English, even though they may be accompanied by an additional Czech abstract. Each contribution is a subject to peer review by at least two independent reviewers, typically at least one from abroad. The Journal appears 2 to 4 times a year. Formally it is divided in annual volumes, each of them including 4 issues.