ПЕРВЫЕ ДАННЫЕ О ЮТЕНБОГААРДИТЕ В РУДЕ ТАСЕЕВСКОГО ЗОЛОТОСЕРЕБРЯНОГО МЕСТОРОЖДЕНИЯ В ВОСТОЧНОМ ЗАБАЙКАЛЬЕ (РОССИЯ)

Abstract

The relevance lies in the need to have complete data on the features of the mineralogy of the unique in terms of gold and silver content ores of shallow gold-silver formation deposits, one example of which is the Taseevskoye deposit in the Baleisky ore field in Eastern Transbaikalia. The purpose of the study is to determine the mineral composition of the rich gold-silver ores of the Taseevsky deposit. The object of the study is a hessite-uytenbogaardite-electrum-chalcopyrite-calcite-quartz mineral association. The subject of the study is the chemical composition and forms of isolation of uytenbogaardite. Method and methodology used are optical and electron microscopy with the determination of forms of precipitation and variations in the chemical composition of uytenbogaardite. The results are the following: for the first time, the rare Au and Ag sulfide uytenbogaardite was identified in the gold-silver ore of the Taseevskoye deposit, its chemical composition was determined, and it was found that it is in association with electrum, chalcopyrite, sphalerite, hessite, quartz, acanthite, cervelite, and petzite. Subspherical forms of aggregates predominate, less often lenticular and veinlets. The size of its crystals and their intergrowths is 0.005 - 0.5 mm. All crystals are nonstoichiometric. The content of the main chemical elements varies within (wt.%): Ag 52.43 - 64.76; Au 22.57 - 37.35; S 7.32 - 12.84. Among the studied individuals of uytenbogardite, three contain from 2.98 to 5.18% Te. Low grade Au, which is associated with uytenbogardite, contains from 43.32 to 56.42% Ag and is electrum by their ratio. Uytenbogaardite was found only in the upper part of the ore zone of the Taseevskoe deposit. This may be a typomorphic feature for determining whether the chalcedony-like quartz containing it belongs to the supra-ore zone of a deposit of a shallow gold-silver formation