Abstract The Valunistoe Au–Ag deposit is the third largest among epithermal deposits in Chukotka after the Kupol and Dvoinoe. It is located at the western closing of the East Chukotka flank zone of the Okhotsk-Chukotka volcanic belt. Volcanic domes (Pravogornenskaya, Zhil’ninskaya, Shakhskaya, Valunistaya, Shalaya, and Oranzhevaya, each is 3–6 km in diameter) have the main ore-controlling significance

Abstract Exhalation ore mineralization is developing in the crater part of the active Kudryavy volcano. Lithogeochemical sampling results have revealed that Re, Au, Ag, As, Bi, Cd, Cu, Ge, In, Mo, Pb, S, Sb, Se, Sn, Te, Tl, W, Zn, Rb, and Cs accumulate in solid fumarole formations. These elements are transported by high-temperature volcanic gases and are deposited in mineral phases in the near-surface

Abstract Based on 5000 analyses of geological prospecting samples from four alunite deposits (Began’, Ukraine; Haft Sanduq, Iran; Bolshaya Kremenyukha and Kachar, Kazakhstan) and 6000 microprobe analyses of alunite, the features of changes in three parameters of alunite quartzite composition have been studied: (1) alunite content, (2) mole fraction of K in alunite, and (3) correspondence of the amount

Abstract— The recognition of the Fouta Djallon–Mandingo territory as an independent bauxite province is substantiated. It is confined to the morphostructure of the same name within a single geotectonic structure, the sedimentary cover of the Sahara Platform, in the tropical monsoon climate zone in West Africa. The bauxite exploration history, reserve and resource estimates, and production dynamics

Abstract The distributions of niobium mineral deposits and their resources on the geological time scale are analyzed. The sampling list includes 45 mineral deposits with their individual resources estimated not less than 105 tons of Nb2О5. The classification of deposits used includes three types, namely, alkaligranitic, foidic, and carbonatitic. The geohistorical variability in niobium metallogeny

Abstract— Geochronological studies have been conducted for ore-hosting rocks (quartz rhyolites, felsitic rhyolites, porphyry granites) of some U deposits of the Yakshi-Yangistau complex within the Balkashino ore center of the Northern Kazakhstan uranium province. According to geological maps of various scales, the rocks were traditionally ascribed to the Early–Middle Devonian (quartz and felsitic rhyolites)

Abstract— This paper considers examples of “hydrogenic” commercial uranium deposits termed as “sandstone-hosted” in the English literature and characterized by so-called “reduced-type alterations.” In addition to the case when they are absent at the deposit, a few characteristic alterations are identified in different ratios, such as rock bleaching, iron redistribution, argillization, carbonatization

Abstract—Various hypotheses, including alternative ones, have been put forward in the literature about the sources of ore substance and ore-forming fluids in the deposits of the Streltsovka ore field, which hosts the world’s largest uranium reserves, in excess of 250 000 t U: (1) uranium transport by ascending flow of ore-forming fluids that have separated from a deep subcrustal or intracrustal uranium-bearing

Abstract— The characteristic features of the manifestations of acid magmatism and metasomatic hydrothermal alteration processes in Southeastern Transbaikalia, an important mining region in Russia, are discussed. The zoned or beltlike distribution of the ores of various metals, uranium in particular, and other mineral deposits is due to the general evolutionary trends of the geodynamic regimes of the

Abstract The present communication is focused on inclusions in topaz from the Mokrusha pegmatite deposit, Urals. These inclusions are intergrown fine crystals of manganocolumbite, cassiterite and a mineral compositionally corresponding to niobium tungstate with minor Mn, Ta, and Fe. Electron microprobe and X-ray diffraction study has revealed that this mineral is identical to that previously described

Abstract The results of experimental modeling of the arsenic transition from natural arsenides to mobile oxidized species in the near-surface environment are discussed. The experiment has been carried out with the samples collected from the dump of the Schlema-Alberoda deposit. Arsenides (safflorite, löllingite, nickeline, rammelsbergite) have been dissolved in acidic and near-neutral oxidative media

Abstract For the first time data on platinum group minerals (PGM) from the deluvial placer of the Veresovka River are given; their root source are dunites of the northern part of the Veresovoborsky massif. Among minerals typical of this type of placers, Pt–Fe minerals, Os–Ir–(Ru) intermetallic compounds, kashinite, bowieite, laurite, erlichmanite, and Ir–Rh thiospinels have been identified. Irarsite

Abstract It was found that in minerals, 27 chemical elements are essential species-defining constituents in all tellurium-bearing mineral species known up to 2018 (166). The number of minerals containing these leading elements were calculated as follows (parentheses): O (85), H (47), Cu (42), Pb (39), Bi (30), S (26), Fe (20), Ag (18), Pd (15), Cl (13); Zn Au (11 minerals each); Ca, Se (7 minerals

Abstract A new Sc-bearing variety of tusionite has been found in the Eastern Pamirs, in the near-miarolitic Dorozhny granite pegmatite complex at the Kukurt pegmatite field (left bank of the Kukurt River, 45 km east of the settlement of Murghab, Gorno-Badakhshan Autonomous Oblast, Tajikistan). Miarolitic pegmatites are related to the alpine leucocratic granites of the Shatput intrusive complex and

Abstract Esseneite from ultramafic xenoliths in dacite flow of the Ten’-01 paleovolcano at the Lena–Vilyui watershed, East Yakutia has been studied. The empirical formula of the mineral has been obtained using electron microprobe analysis: \({\text{C}}{{{\text{a}}}_{{0.99}}}{\text{Fe}}_{{0.52}}^{{3 + }}{\text{M}}{{{\text{g}}}_{{0.32}}}{\text{Fe}}_{{0.06}}^{{2 + }}{\text{T}}{{{\text{i}}}_{{0.05}}}{\text{Mn}}_{{0

Abstract The new data for the segregations, paragenetic assemblage, and composition of bismuthian jamesonite from gold–quartz mineralization at the Sredny Golgotai deposit located in the eastern part of the Mongolia–Okhotsk orogenic belt are reported. This mineral occurs as two varieties (I, II), which are slightly different in composition and chemically close to bismuthian jamesonite (“sakharovaite”)

Abstract Diamonds with garnet inclusions have been studied from the Udachnaya, Zapolyarnaya, Komsomolskaya-Magnitnaya, Yubileynaya, Komsomolskaya, Aikhal, Mir, and Mayskaya kimberlite pipes of the Yakutia diamondiferous province. A positive correlation has been revealed between the positions of the main peaks in the Raman spectra of garnets and their chemical composition. A method for determining the

Abstract A group of accessory ore minerals is revealed in rocks of the Galmoenan mafic-ultramafic massif (Koryak Upland, Kamchatka, Russia), represented by native metals (iron, copper, zinc, and silver), iron-nickel and cobalt-iron intermetallic compounds, sulfides (pentlandite, cobaltpentlandite, pyrrhotite, sphalerite, heazlewoodite, millerite, shandite, pyrite, chalcopyrite, and Cu3S2 phase), arsenides

Abstract Thermal behavior of catapleiite, ideally Na2ZrSi3O9 ⋅ 2H2O, has been investigated with the X-ray diffraction, electroconductivity measurements using impedance spectroscopy, dynamic scanning calorimetry, thermal gravimetry, and infrared spectroscopy. The high-temperature transformation product of catapleiite obtained after annealing of catapleiite at 1000°C has been studied. This is a new microporous