Blue sapphire of gem quality was recently discovered in spinel–chlorite–muscovite rock within meta-ultramafites near the Ilmenogorsky alkaline complex in the Ilmen Mountains of the South Urals. More than 20 minerals were found in the assemblage with the blue sapphire. These sapphire-bearing rocks are enriched in LREE and depleted in HREE (with the negative Eu anomalies) with REE distribution similar to those in miascites (nepheline syenite) of the Ilmenogorsky alkaline complex. 87Sr/86Sr ratios in the sapphire-bearing rocks varied from 0.7088 ± 0.000004 (2σ) to 0.7106 ± 0.000006 (2σ): epsilon notation εNd is −7.8. The Rb-Sr isochrone age of 289 ± 9 Ma was yielded for the sapphire-bearing rocks and associated muscovite. The blue sapphires are translucent to transparent and they have substantial colorless zones. They occur in a matrix of clinochlore-muscovite as concentric aggregates within spinel-gahnite coronas. Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) analyses showed values with trace elements typical for “metamorphic” blue sapphires, with Ga/Mg < 2.7, Fe/Mg < 74, Cr/Ga > 1.5 (when Cr is detectable), and Fe/Ti < 9. Sapphires overlap “metasomatic” at “sapphires in alkali basalts” field on the FeO–Cr2O3–MgO–V2O3 versus FeO + TiO2 + Ga2O3 discriminant diagram. The sapphires formed together with the spinel-chlorite-muscovite rock during metasomatism at a contact of orthopyroxenites. Metasomatic fluids were enriched with Al, HSFE, and LILE and genetically linked to the miascite intrusions of Ilmenogorsky complex. The temperature required for the formation of sapphire–spinel–chlorite–muscovite rock was 700–750 °C and a pressure of 1.8–3.5 kbar.

The technogenic mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the burned dumps of the Chelyabinsk coal basin have been investigated by single-crystal X-ray diffraction, scanning electron microscopy and high-temperature powder X-ray diffraction. The NH4MgCl3·6H2O phase is monoclinic, space group C2/c, unit cell parameters a = 9.3091(9), b = 9.5353(7), c = 13.2941(12) Å, β = 90.089(8)° and V = 1180.05(18) Å3. The crystal structure of NH4MgCl3·6H2O was refined to R1 = 0.078 (wR2 = 0.185) on the basis of 1678 unique reflections. The (NH4)2Fe3+Cl5·H2O phase is orthorhombic, space group Pnma, unit cell parameters a = 13.725(2), b = 9.9365(16), c = 7.0370(11) Å and V = 959.7(3) Å3. The crystal structure of (NH4)2Fe3+Cl5·H2O was refined to R1 = 0.023 (wR2 = 0.066) on the basis of 2256 unique reflections. NH4MgCl3·6H2O is stable up to 90 °C and then transforms to the less hydrated phase isotypic to β-Rb(MnCl3)(H2O)2 (i.e., NH4MgCl3·2H2O), the latter phase being stable up to 150 °C. (NH4)2Fe3+Cl5·H2O is stable up to 120 °C and then transforms to an X-ray amorphous phase. Hydrogen bonds provide an important linkage between the main structural units and play the key role in determining structural stability and physical properties of the studied phases. The mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O are isostructural with natural minerals novograblenovite and kremersite, respectively.

The article describes morphological and typological characteristics of non-ferrous metal, determines the for-mulae of alloys, as well as identifies techniques used for the production of tools by the Alekseyevka-Sargary cul-ture from the South Trans-Urals (15th/14th and 12th/11th BC). We carried out the morphological and typological study of the non-ferrous metal along with the X-ray fluorescence (Institute of Archaeology RAS, Institute of Mine-ralogy UB RAS; X-MET3000TX analysers from Oxford Instruments Analytical, M1 Mistral from Bruker Nano GmbH) and metallographic (Tyumen Scientific Centre SB RAS; Zeiss Axio Observer D1m microscope) analyses. A total of 19 tools exhibiting morphology inherent to the tool collections of the Alekseyevka-Sargary culture were selected for the study. These tools comprised random finds and items from the settlements of the Chelyabinsk and Kurgan regions of Russia, as well as from the Kostanay Region of Kazakhstan: daggers, а spearhead, sick-les, socketed chisels, a spear end cap and single-blade knives. A group of tools and weapons characteristic of all Eurasian cordoned-ware cultures was distinguished — daggers with handguards and socketed grooved chisels. In addition, weapons characteristic of the sites attributed to the Alekseyevka-Sargary culture (Saryarka, Altai, and Semirechye) were identified within the weapon complex of the South Trans-Urals. These weapons included bush hooks of the Sosnovaya Maza type, knives having marked handles, spearheads with holes and socketed straight-blade chisels. The metal of the South Trans-Urals is distinguished by the marked heterogeneity of its chemical composition with the predominance of low-alloyed bronzes Cu–Sn, Cu–Sn–As and Cu–As (66.7 %). There are 4 pure copper items, as well as products from the complex alloy Cu–Sn–As–Ni–Co and products with elevated iron concentrations (up to 2.68 %). These data indicate that the population experimented in the course of metal-lurgical processing of raw materials; they transitioned to smelting metal from sulphide ores or to the smelting of copper with sulphide or silicate nickel ores of the Ufaley Massif (deposits in the Chelyabinsk Region). South Ural craftsmen produced bronze and copper primarily using technologies for casting tools in one-sided (with flat cov-ers) and two-sided moulds. The casting was followed by refining operations using the cold forming technology with the intervals of low-temperature forging modes. This choice of temperature is justified in the procession of low-alloyed bronze. Clearly, the centre for metal production of the Alekseyevka-Sargary culture in the South Trans-Urals was a metallurgical one, with the development of both oxidised and sulphide deposits in the South Urals. Innovative technologies of smelting copper with chalcopyrite, arsenopyrite, and nickel-containing ores were introduced. The complex of tools attributed to the Alekseyevka-Sargary tribes from the Tobol area is generally identical to the bronze inventory from Saryarka, Altai and Kyrgyzstan. Local craftsmen employed the traditional technologies of processing copper and bronze commonly used in the centres for metal production throughout the area of the Alekseyevka-Sargary culture, working primarily with bronzes low-alloyed by tin. As in previous eras, tin ingots and products were delivered from Central Kazakhstan and Ore Altai, but in much smaller quantities. The small number of products and the data of an analytical study indicate the relocation of the main centres for metal production of the Alekseyevka-Sargary culture from the Urals region (as compared to the big centres of Petrovka and Alakul cultures) to Central and Eastern Kazakhstan, up to Xinjiang in China.

The previous and new data on minerals and mineral assemblages of the Sugur copper deposit in Sugur Mountains of South Urals are summarized. The ores of the deposit host abundant calcite, andradite, diopside, magnetite, chromite and serpentine together with pyrite, chalcopyrite, chalcocite, pyrrhotite, millerite, and rare baddeleyite. The genesis of the deposit was previously considered both contact-metasomatic and hydrothermal. The new data allow us to attribute copper mineralization to a skarn-carbonatite system, which is locally recognized in the Karabash ultramafc massif.

New geochemical, mineralogical, and Rb–Sr and Sm–Nd isotopic data have been obtained on corundum plagioclasites–kyshtymites from the 5th Versta deposit (South Urals, Russia). The genetic link of miaskites and kyshtymites is shown. The formation of the kyshtymites is associated with the redistribution and accumulation of aluminum, calcium, HFSE, and LIL-elements at the stage of tectonic-metamorphic deformations of the Ilmenogorsky–Vishnevogorsky alkaline complex.