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The crystal structure of the rare mineral caryochroite is determined for the first time using X-ray diffractometry and electron microdiffraction data. The new idealized crystal formula of the mineral is [Na(Sr0.5Ca0.5)Mg]3[Fe Mn()]10(Ti2Si12)O37(OH)14(Н2О)3. The parameters of the monoclinic unit cell refined by the least square method are a 16.550(3), b 5.281(2), c 24.25(3) Å, β 93.0°, Z = 2, space group P2/n. The crystal structure of caryochroite is a new type of Ti–Si lattice responsible for the large structural channels, which are able to enclose the exchange cations and a high amount of water components (OH groups and H2O molecules). [ABSTRACT FROM AUTHOR]

Using selected aeria difraction and X-ray powder data, a structural model was constructed for the rare mineral vyalsovite FeCaAlS(OH)5. Parameters of the elementary monoclinic cell а 5.205, b 21.402, c 14.400 Å, β 95°, sp. gr. Cm. The crystal structure of vyalsovite is the first example of a hybrid structure composed of commensurate iron sulfide and hydroxide modules. [ABSTRACT FROM AUTHOR]

An Erratum to this paper has been published: https://doi.org/10.1134/S1028334X23070140 [ABSTRACT FROM AUTHOR]

A structural model of the rare mineral yushkinite [(Mg0.60Al0.30V0.10)Σ1.0(OH)2] [V0.875S2] is studied using the data of electron microdiffraction and the X-ray powder pattern. The parameters of the elementary trigonal cell are а = 3.25 Å and с = 11.40 Å, with the space group . The structure is composed of brucite and sulfide layers alternating along the с-axis, which are commensurate in the basal plane. The layer structure determines the finely dispersed nature of yushkinite morphology and perfect cleavage along {001}. The idealized yushkinite formula is refined, and trigonal symmetry is established in contrast to the hexagonal one proposed earlier. [ABSTRACT FROM AUTHOR]

A new concept of the formation of glauconite from the Paleocene deposits of the sedimentary cover of the southwestern part of the Near-Volga monocline is presented. It was formed as a result of halmyrolysis of ash material in lake conditions. Glauconitization is confined to the Paleogene thermal maximum and the periphery of active volcanism along the entire mobile belt. In this connection, it is widely distributed in the Paleogene deposits. Structural and crystal-chemical features of glauconite, stages of crystallization of its aggregates, paragenetic associations with smectite, kaolinite, and zeolite, as well as the presence of ore minerals indicate its authigenic origin. The authigenic origin is confined to the formations of temporary, episodically submerging shallow marine basins. An applied scheme of discrimination of glauconites by their crystallochemical features has been developed. The discrimination diagram can be used to determine the specific conditions of the sedimentation basin, which are expressed in the progradation cycles of glauconite accumulation. The cycles were controlled by induced depressions within the Russian plate. [ABSTRACT FROM AUTHOR]

An Erratum to this paper has been published: https://doi.org/10.1134/S1028334X23070334 [ABSTRACT FROM AUTHOR]

Montmorillonite of natural modification with organic complexes was found for the first time in bentonite of the Tikhmenevo deposit on Sakhalin Island. The data obtained permitted us to identify within the interlayer space of the bentonite chain polymethylene, alkylammonium, and other fragments of humic molecules occurring in the humus surrounding the bentonite. [ABSTRACT FROM AUTHOR]

The main source of aluminum is bauxite ores and their basic mineral components gibbsite Al(OH)3 and boehmite AlO(OH). Alumina Al2O3 is formed by various methods of decomposition of these components, electrolytically decomposed to pure Al. It has been established that gibbsite is the basic and often the only mineral of aluminum in the Mesozoic and Cenozoic laterite bauxites, representing most of the world's reserves. Boehmite is formed in laterite-sedimentary bauxites, during lateritization and desilication of albic water-sedimentary continental sediments, as well as the underlying bleached parent rocks. The formation of boehmite is associated with an excess of aluminum generally due to its input from above. Boehmite predominates in the Paleozoic laterites. The formation of aluminum monohydrate is explained by a decrease in the oxidation–reduction potential. [ABSTRACT FROM AUTHOR]

The article focuses on a study on biogenic nanohematite in the bauxite-bearing weathering crust in basalt from South Vietnam. It mentions that the method of differential gravimetry and scanning calorimetry were applied to assess hematite during heating. It further states that the magnetic properties of biogenic nanohematite were studied at the Laboratory of Geomagnetism, Institute of Physics of the Earth, at the Russian Academy of Sciences in Moscow, Russia.

The article discusses a study which investigates the impact of the particle size of Kaolinite on its crystallomorphological properties, found at the Zhuravlinyi Log Deposit in Southern Urals, Russia. The study uses a transmitting electron microscope Phillips CM 12 fitted with a microprobe instrument for the control of sample composition. It notes that the study clearly depicts the dependence of the degree of crystallinity and the kaolinite structure completeness on the particle size. Also, it mentions that the development of crystallmorphological parameters of kaolinite were associated to the small fractions, beginning from 10μ which is manifested in the fraction of <0.5 μm.