Hostname: page-component-76fb5796d-2lccl Total loading time: 0 Render date: 2024-04-26T01:32:21.968Z Has data issue: false hasContentIssue false
  • English
  • Français

Gold to aurostibite transformation and formation of Au-Ag-Sb phases: the Krásná Hora deposit, Czech Republic

Published online by Cambridge University Press:  02 January 2018

Jiří Zachariáš  and
Matěj Němec
Jiří Zachariáš*
Affiliation:
Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Prague 2, Czech Republic
Matěj Němec
Affiliation:
Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Prague 2, Czech Republic
*
*E-mail: jiri.zacharias@natur.cuni.cz
Get access Rights & Permissions [Opens in a new window]

Abstract

Rare phases of the Au–Ag–Sb system were recognized in the Krásná Hora Sb-Au deposit (Sb 1.5–3 wt.%; Au 3–5 ppm), Czech Republic which correspond to auriferous dyscrasite (up to 7 at.% Au), auriferous allargentum (up to 34 at.% Au), and an unnamed phase with composition similar to the eutectics (E1, E2) of the experimental Au–Ag–Sb system. The dominant ore mineral is stibnite with rare native antimony, native gold and a Ag-Au alloy. Textural relationships are well established: stibnite (early) →gold → aurostibite → native antimony (late). Gold is present in four generations: Au-1 (0–15 at.% Ag) is the most abundant type; Au-2 (20–70 at.% Ag) forms thin rims along intra-grain boundaries of Au-1; Au-3 and Au-4 are rare and almost pure (∼0 at.% Ag). The formationof most of the Au-2 and of Au-Ag-Sb phases is associated with Ag-mobilization coupled with the Au-1 to aurostibite transformation via dissolution-precipitation and solid-state diffusion processes at temperatures <200°C.

Keywords

Au–Ag–Sb systemAu-Ag alloyaurostibitedyscrasiteallargentumgold depositsKrásná Hora depositBohemian Massif
Type
Research Article
Information
Mineralogical Magazine , Volume 81 , Issue 4 , August 2017 , pp. 987 - 999
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2017

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ashley, P.M., Creagh, C.J. and Ryan, C.G. (2000) Invisible gold in ore and mineral concentrates from the Hillgrove gold-antimony deposits, NSW, Australia. Mineralium Deposita, 35, 285–301.CrossRefGoogle Scholar
Bellot, IP, Leroug, C., Bailly, L. and Bouchot, V (2003) The Biards Sb-Au—bearing shear zone (Massif Central, France): An indicator of crustal-scale trans-current tectonics guiding late Variscan collapse. Economic Geology, 98, 1427–1447.CrossRefGoogle Scholar
Blüml, A., Holub, M. and Suček, P. (1995) The final closing down report from the Krásná Hora Sb-Au deposit. Unpublished report, Príbram, Rudné doly Príbram, 134 pp. [in Czech].Google Scholar
Boiron, M.C., Cathelineau, M., Dubessy, J. and Bastoul, A.M. (1990) Fluids in Hercynian Au veins from the French Variscan belt. Mineralogical Magagazine, 54, 231–243.CrossRefGoogle Scholar
Bouchot, V., Gros, Y. and Piantone, P. (1994) Dynamic of shallow late-Variscan gold mineralization: The Le Châtelet Au-arsenopyrite quartz veins, Massif Central, France. Mineralium Deposita, 29, 461–473.CrossRefGoogle Scholar
Bouchot, V., Milési, J.P., Lescuyer, J.L. and Ledru, P. (1997) Les minéralisation auriferes de la France dans leur cadre géologique autour de 300 Ma. Chronique de la Recherche Miniere, 528, 13–62.Google Scholar
Buchholz, P., Oberthür, T, Liiders, V and Wilkinson, J. (2007) Multistage Au-As-Sb mineralization and crustal-scale fluid evolution in the Kwekwe District, Midlands Greenstone Belt, Zimbabwe: A combined geochemical, mineralogical, stable isotope, and fluid inclusion study. Economic Geology, 102, 347–378.CrossRefGoogle Scholar
Cabri, L.J. (2007) Mineralogical evaluation of Au-Sb-As mineralization from the AD—MW Zones, Clarence Creek Property, New Brunswick. Pp. 517–534 in: Proceedings of the 39th Annual Canadian Mineral Processors Conference 2007. Paper 30.Google Scholar
Cipriani, C., Corazza, M. and Mazzetti, G. (1996) Reinvestigation of natural silver antimonides. European Journal of Mineralogy, 8, 1347–1350.CrossRefGoogle Scholar
Deschênes, G., Xia, C., Fulton, M., Cabri, L.J. and Price, J. (2007) Leaching of a refractory gold ore sample from the central zone, Clarence stream property, New Brunswick, Canada. Pp. 195–203 in: World Gold 2007 Conference Proceedings. Australasian Institute of Mining and Metallurgy, Victoria, Australia.Google Scholar
Dill, H.G., Weiser, T and Bernhardt, I.R. (1995) The composite gold-antimony vein deposit at Kharma (Bolivia). Economic Geology, 90, 51–66.CrossRefGoogle Scholar
Graham, A.R. and Kaiman, S. (1952) Aurostibite, AuSb2; a new mineral in the pyrite group. American Mineralogist, 37, 461.Google Scholar
Gumiel, P. and Arribas, A. (1987) Antimony deposits in the Iberian Peninsula. Economic Geology, 82, 1453–1463.CrossRefGoogle Scholar
Janoušek, V., Wiegand, B.A. andZak, 1 (2010) Dating the onset of Variscan crustal exhumation in the core of the Bohemian Massif: new U-Pb single zircon ages from the high-K calc-alkaline granodiorites of the Blatna suite, Central Bohemian Plutonic Complex. Journal of the Geological Society, 167, 347–360.Google Scholar
Jedwab, 1 and Chuva, J.M. (1992) Reflected-light microscope and SEM/EMP observations on the behaviour of aurostibite (AuSb2) during amalgamation. Mineralogical Magazine, 565, 561–565.Google Scholar
Johan, Z. and Šrein, V (1998) Un nouvel oxyde naturel de Au et Sb. Comptes Rendus de I Académie des Sciences-Series IIA-Earth and Planetary Science, 326, 533–538.Google Scholar
Kovalev, K.R., Kalinin, Y.A., Naumov, E.A., Pirajno, F. and Borisenko, A.S. (2009) A mineralogical study of the Suzdal sediment-hosted gold deposit, Eastern Kazakhstan: Implications for ore genesis. Ore Geology Reviews, 35, 186–205.CrossRefGoogle Scholar
Makkonen, H. and Ekdahl, E. (1988) Petrology and structure of the early Proterozoic Pirilä gold deposit in southeastern Finland. Bulletin of the Geological Society of Finland, 60, 55–66.CrossRefGoogle Scholar
Makovicky, E., Chovan, M. and Bakos, F. (2007) The stibian mustard gold from the Kriváň Au deposit, Tatry Mts., Slovak Republic. Neues Jahrbuch für Mineralogie-Abhandlungen, 184, 207–215.CrossRefGoogle Scholar
Maličký, P. (1991) Mineralogical and technological research of the Krásná Hora deposit ore. Unpublished MSc thesis, University of Chemistry and Technology, Prague, 160 pp. [In Czech].Google Scholar
Millonig, L.J., Groat, L.A. and Linnen, R. (2015) Geological and mineralogical report: Engineer Mine. Unpublished research report prepared for the BCGold Corp., 53 pp.Google Scholar
Nemec, M. (2014) Genesis of Au-Sb ores at the Krásná Hora deposit. Unpublished MSc thesis, Charles University, Faculty of Science, Prague, 67 pp. [in Czech].Google Scholar
Nemec, M. and Zachariáš, J. (2017) The Krásná Hora, Milešov and Pficovy Sb-Au ore deposits, Bohemian Massif: mineralogy, fluid inclusions and stable isotope constraints on the deposit formation. Mineralium Deposita, https://doi.org/10.1007/s00126-017-0734-8 Google Scholar
Novák, J. (1955) Mineralogy and the genesis of the Krásná Hora belt — the mineralogical and petrogra-fical research of the ore. Unpublished report, Kutná Hora, ÚVR Kutná Hora, Czech Republic, 52 pp. [in Czech].Google Scholar
Novoselov, K., Belogub, E., Kotlyarov, V and Mikhailov, A. (2015) Ore mineralogy and formation conditions of the Pirunkoukku gold occurrence (Finland). European Journal of Mineralogy, 27, 639–649.CrossRefGoogle Scholar
Petruk, W., Harris, D.C, Cabri, L.J. and Stewart, J.M. (1971) Characteristics of the silver-antimony minerals in the silver-arsenide deposits of the Cobalt-Gowganga region, Ontario. The Canadian Mineralogist, 11, 187–195.Google Scholar
Sobotka, J. (1954) Aurostibite AuSb2 on the ore veins of Krásná Hora and Milešov (first macroscopical ocur-ence). Rozpravy ČSAV, Řada matem. aprírodních ved, 64, 43–60 [in Czech].Google Scholar
Spiridonov, E.M., Krivitskaya, N.N., Bryzgalov, I.A., Kulikova, I.M. and Gorodetskaya, M.D. (2010) Bismuth rich aurostibite: A product of maldonite replacement in a volcanogenic — plutonogenic Darasun deposit (Eastern Transbaikalia). Doklady Earth Sciences, 435, 1611–1613.CrossRefGoogle Scholar
Tikhomirova, V.I., Akhmedzhanova, G.M. and Nekrasov, I.Y (1988) Possible mechanism of the generation of mustard gold in the interaction of aurostibite with chloride solutions, as indicated by electrochemical investigations. Doklady Earth Science Sections, 303, 213–216.Google Scholar
Zacharias, I, Pertold, Z., Pudilová, M., Žák, K., Pertoldova, I, Stein, H. and Markey, R. (2001) Geology and genesis of Variscan porphyry-style gold mineralization, Petráčkova hora deposit, Bohemian Massif, Czech Republic. Mineralium Deposita, 36, 517–541.CrossRefGoogle Scholar
Zacharias, I, Paterová, B. and Pudilová, M. (2009) Mineralogy, fluid inclusion, and stable isotope constraints on the genesis of the Roudny Au-Ag deposit, Bohemian Massif. Economic Geology, 104, 53–72.CrossRefGoogle Scholar
Zacharias, I, Žák, K., Pudilová, M. and Snee, L.W. (2013) Multiple fluid sources/pathways and severe thermal gradients during formation of the Jílové orogenic gold deposit, Bohemian Massif, Czech Republic. Ore Geology Reviews, 54, 81–109.CrossRefGoogle Scholar
Zachariáš, J., Morávek, P., Gadas, P. and Pertoldová, J. (2014) The Mokrsko-West gold deposit, Bohemian Massif, Czech Republic: Mineralogy, deposit setting and classification. Ore Geology Reviews, 58, 238–263.CrossRefGoogle Scholar
Zoro, E., Servant, C. and Legendre, B. (2006) Experimental study of the phase diagram of the Ag-Au-Sb ternary system. Journal of Alloys and Compounds, 426, 193–199.CrossRefGoogle Scholar
Zoro, E., Servant, C. and Legendre, B. (2007a) Thermodynamic assessment of the Ag-Au-Bi and Ag-Au-Sb systems. Journal of Thermal Analysis and Calorimetry, 90, 347–353.CrossRefGoogle Scholar
Zoro, E., Servant, C. and Legendre, B. (2007b) Thermodynamic modeling of the Ag-Au-Sb ternary system. Journal of Phase Equilibria and Diffusion, 28, 250–257.CrossRefGoogle Scholar
Supplementary material: Image

Zachariáš and Němec supplementary material

Supplementary Figure

Download Zachariáš and Němec supplementary material(Image)
Image 4 MB