The morphology and chemical composition of native gold from the Murtykty deposit (South Urals) are discussed in the paper. Native gold is subdivided into fve types: 1) inclusions in sulfdes, 2) grains in fractures and interstices of pyrite and other sulfdes, 3) grains at the boundaries of sulfdes and gangue minerals, 4) inclusions in gangue minerals and their interstices and 5) «free¬ grains from heavy concentrates. The chemical composition of 128 gold grains is studied. In accordance with Ag content (from 6.49 to 30.8 wt. %), native gold from the deposit varies from high- to low-fneness (rare grains). Native gold in sphalerite contains Cu (0.85–2.27 wt. %)., The morphological features of 264 gold grains are quantifed using Image Tool software. The morphological characteristics of native gold from types 1–4 are similar. The data on morphology and size of native gold grains can be used for improvement of technology of gold extraction.

Keywords: Murtikty deposit, native gold, South Urals.

Received 29.10.2020, аccepted 29.10.2020

N.S. Chukhareva, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Institute of Mineralogy, Miass, Chelyabinsk oblast, 456317 Russia; nau_2004@mail.ruE.V. Belogub,

Yu.A. Ryzhkova, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Institute of Mineralogy, Miass, Chelyabinsk oblast, 456317 Russia; 

I.A. Blinov, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Institute of Mineralogy, Miass, Chelyabinsk oblast, 456317 Russia; 

M.A. Rassomakhin, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Institute of Mineralogy, Miass, Chelyabinsk oblast, 456317 Russia; 

K.A. Novoselov, South Urals Federal Research Center of Mineralogy and Geoecology UB RAS, Institute of Mineralogy, Miass, Chelyabinsk oblast, 456317 Russia; 

1. Belogub E.V. (2018) [Information report on results of mineralogical and petrographic study of ores and host rocks of the Murtykty deposit (Bashkortostan) in 2017–2018]. Miass, 47 p. (in Russian)
2. Belogub E.V. (2009) [Supergenesis of sulfde deposits in the southern Urals]. Dissertation for of Doctor of Geological and Mineralogical Sciences. St. Petersburg SPbGU, 617 p. (in Russian)
3. Belogub E.V., Novoselov K.A., Kotlyarov V.A., Fadina I.B. (2006) [Mineralogy of oxidized ores of the gold-polymetallic Deposit IK-Davlyat (southern Urals)]. Zapiski RMO [Proceedings of Russian Mineralogical Society], 135(5), 35–43. (in Russian)
4. Bocharov V.A., Abryutin D.V. (2011) [Technology of gold-bearing ores]. Moscow, MISiS, 420 p. (in Russian)
5. Chryssoulis S.L., McMullen J. (2016) Mineralogical investigation of gold ores. Gold ore processing (Second edition) (ed. M.D. Adams). Amsterdam, Elsevier, 57–93.
6. Geological map of the Russian Federation Scale of 1:1 000 000, sheet N-40(4) (2001). Edited by V.I. Kozlov, Ufa.
7. Maslennikov V.V., Maslennikova S.P., Lein A.Yu. (2019) [Mineralogy and geochemistry of ancient and modern black smokers]. Moscow, RAN, 832 p. (in Russian)
8. Makarova V.N. (2013) [Geotourism and «golden dust» of centuries]. Arkheografa Yuzhnogo Urala: okruzhayushchaya sreda, prirodnye resursy i geologicheskie pamyatniki v istorii, culture i zhizneobespechenii narodov Evrazii. Materialy XIII Vserossiyskoy nauchnoprakticheskoy konferentsii, posvyashchennoy godu okruzhayushcheey sredy [Archeography of the South Urals: environment, natural resources and geological sites of history, culture and livelihoods of people of Eurasia. Proceedings of the XIII All-Russian scientifc and practical conference dedicated to the year of the environment]. Ufa, IEI UNTS RAN, 54–62. (in Russian)
9. Morrison G.W., Rose W.J., Jaireth S. (1991) Geological and geochemical controls on the silver content (fneness) of gold in gold-silver deposits. Ore Geology Reviews, 6(4), 333–364.
10. Mostovich V.Ya. (1923) [Cyanidation of gold tellurides]. Izvestiya Tomskogo Tkhnologicheskogo Instituta [Proceedings of Tomsk Technological Institute], 44, 56–87. (in Russian)
11. Novoselov K., Belogub E. (2005) Gold-polymetallic mineralisation of the Il’inskoe ore feld (South Urals). Geochemistry, Mineralogy and Petrology, 43, 138–141.
12. Paduchina Yu.A., Chukhareva N.S., Novoselov K.A., Palenova E.E., Belogub E.V., Blinov I.A., Artemyev D.A., Rassomakhin M.A. (2019) [Mineralogy of precious metals of the Murtykty gold Deposit, southern Urals]. Mineralogiya [Mineralogy], 5(2), 57–69. (in Russian)
13. Petrovskaya V.N. (1973) [Native gold]. Moscow, Nauka, 348 p. (in Russian)
14. Sazonov V.N., Ogorodnikov V.N., Koroteev V.A., Polenov Yu.A. (1999) [Urals gold deposits]. Yekaterinburg, UGGGA, 570 p. (in Russian)
15. Salikhov D.N., Kovalev S.G., Belikova G.I., Berdnikov P.G. (2003) [Minerals of the Republic of Bashkortostan (gold)]. Part 1. Ufa, Ekologiya, 222 p. (in Russian)
16. Seravkin I.B., Znamensky S.E., Rodicheva Z.I. (2013) [Zonality of occurrence of gold deposits in the South Urals]. Geological collection no. 10. Ufa, 225–235. (in Russian)
17. Vikentiev I.V. (2004) [Formation conditions and metamorphism of pyrite ores]. Moscow, Nauchny mir, 338 p. (in Russian)
18. Yannopoulos J.C. (1991) The extractive metallurgy of gold. Van Nostrand Reinhold, New York, 282 p.
19. Znamenskiy S.E. (2010) [The geological formation conditions and genesis of gold-sulfde deposits of the Magnitogorsk Megazone]. Magmatizm i metamorfzm v istorii zemli. XI Vserossiyskoe petrografcheskoe soveshchanie [Magmatism and metamorphism in evolution of the Earth. XI All-Russian petrographic meeting]. Yekaterinburg, UGGU, 257–258. (in Russian)