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102. m = 0.1): Structure Refinement, Framework Topology, and Possible Na+-Ion Migration Paths

Author

Kabanova, Natalya A., Panikorovskii, Taras L., Shilovskikh, Vladimir V., Vlasenko, Natalya S., Yakovenchuk, Victor N., Aksenov, Sergey M., Bocharov, Vladimir N., and Krivovichev, Sergey V.

Subjects
crystal structure, ion migration, topology, parakeldyshite, transformation, Raman spectroscopy, Voronoi analysis, keldyshite
Abstract

The Na2&minus, nHn[Zr(Si2O7)]∙mH2O family of minerals and related compounds (n = 0&ndash, 0.5, m = 0.1) consist of keldyshite, Na3H[Zr2(Si2O7)2], and parakeldyshite, Na2[Zr(Si2O7)], and synthetic Na2[Zr(Si2O7)]∙H2O. The crystal structures of these materials are based upon microporous heteropolyhedral frameworks formed by linkage of Si2O7 groups and ZrO6 octahedra with internal channels occupied by Na+ cations and H2O molecules. The members of the family have been studied by the combination of theoretical (geometrical&ndash, topological analysis, Voronoi migration map calculation, structural complexity calculation), and empirical methods (single-crystal X-ray diffraction, microprobe analysis, and Raman spectroscopy for parakeldyshite). It was found that keldyshite and parakeldyshite have the same fsh topology, while Na2ZrSi2O7∙H2O is different and has the xat topology. The microporous heteropolyhedral frameworks in these materials have a 2-D system of channels suitable for the Na+-ion migration. The crystal structure of keldyshite can be derived from that of parakeldyshite by the Na+ + O2&minus, &harr, OH&minus, + □ substitution mechanism, widespread in the postcrystallization processes in hyperagpaitic rocks.

Published
2020
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103. Goldhillite, Cu5Zn(AsO4)2(OH)6⋅H2O, a new mineral species, and redefinition of philipsburgite, Cu5Zn[(AsO4)(PO4)](OH)6⋅H2O, as an As–P ordered species

Author

Ismagilova, Rezeda M., Rieck, Branko, Kampf, Anthony R., Giester, Gerald, Zhitova, Elena S., Lengauer, Christian L., Krivovichev, Sergey V., Zolotarev, Andrey A., Ciesielczuk, Justyna, Mikhailova, Julia A., Belakovsky, Dmitry I., Bocharov, Vladimir N., Shilovskikh, Vladimir V., Vlasenko, Natalia S., Nash, Barbara P., and Adams, Paul M.

Published
2022
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108. Dioskouriite, CaCu4Cl6(OH)4∙4H2O: A New Mineral Description, Crystal Chemistry and Polytypism

Author

Pekov, Igor V., primary, Zubkova, Natalia V., additional, Zolotarev, Andrey A., additional, Yapaskurt, Vasiliy O., additional, Krivovichev, Sergey V., additional, Belakovskiy, Dmitry I., additional, Lykova, Inna, additional, Vigasina, Marina F., additional, Kasatkin, Anatoly V., additional, Sidorov, Evgeny G., additional, and Pushcharovsky, Dmitry Yu., additional

Published
2021
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113. The Na2−nHn[Zr(Si2O7)]∙mH2O Minerals and Related Compounds (n = 0–0.5; m = 0.1): Structure Refinement, Framework Topology, and Possible Na+-Ion Migration Paths

Author

Kabanova, Natalya A., primary, Panikorovskii, Taras L., additional, Shilovskikh, Vladimir V., additional, Vlasenko, Natalya S., additional, Yakovenchuk, Victor N., additional, Aksenov, Sergey M., additional, Bocharov, Vladimir N., additional, and Krivovichev, Sergey V., additional

Published
2020
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114. Na2Cu+[Cu2+3O](AsO4)2Cl and Cu3[Cu3O]2(PO4)4Cl2: two new structure types based upon chains of oxocentered tetrahedra

Author

Kornyakov, Ilya V. and Krivovichev, Sergey V.

Abstract

Single crystals of Na2Cu+[Cu2+3O](AsO4)2Cl (1) and Cu3[Cu3O]2(PO4)4Cl2(2) were prepared by chemical vapor transport reactions. Both crystal structures are based upon the same [O2Cu6]8+chains formed by corner-sharing (OCu4)6+tetrahedra and interconnected by (TO4)3−(T= P, As) tetrahedra into porous {[OCu3](TO4)2Cl}3−frameworks. The channels within the frameworks are occupied by Na+, Cu+and Cl−ions in the crystal structure of 1, whereas the channels in the structure of 2contain edge-sharing CuO4Cl tetragonal pyramids. Both compounds are structurally related to the previously described synthetic Na2Cu+[Cu2+3O](PO4)2Cl and NaCu2+[Cu2+3O](PO4)2Cl. The compound 2is structurally and chemically related to yaroshevskite, Cu3[Cu3O]2(VO4)4Cl2, a mineral discovered in volcanic fumaroles, but the two structure types are drastically different. The crystal chemical analysis of the title and related compounds allows to recognize a family of at least four compounds based upon {[OCu3](TO4)2Cl}3−frameworks with channels occupied by different chemical constituents.

Published
2022
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118. Exploring Carbon Mineral Systems: Recent Advances in C Mineral Evolution, Mineral Ecology, and Network Analysis

Author

Morrison, Shaunna M., primary, Buongiorno, Joy, additional, Downs, Robert T., additional, Eleish, Ahmed, additional, Fox, Peter, additional, Giovannelli, Donato, additional, Golden, Joshua J., additional, Hummer, Daniel R., additional, Hystad, Grethe, additional, Kellogg, Louise H., additional, Kreylos, Oliver, additional, Krivovichev, Sergey V., additional, Liu, Chao, additional, Merdith, Andrew, additional, Prabhu, Anirudh, additional, Ralph, Jolyon, additional, Runyon, Simone E., additional, Zahirovic, Sabin, additional, and Hazen, Robert M., additional

Published
2020
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125. Negevite, the pyrite-type NiP2, a new terrestrial phosphide

Author

Britvin, Sergey N., primary, Murashko, Michail N., additional, Vapnik, Yevgeny, additional, Polekhovsky, Yury S., additional, Krivovichev, Sergey V., additional, Vereshchagin, Oleg S., additional, Shilovskikh, Vladimir V., additional, and Krzhizhanovskaya, Maria G., additional

Published
2020
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126. Transjordanite, Ni2P, a new terrestrial and meteoritic phosphide, and natural solid solutions barringerite-transjordanite (hexagonal Fe2P–Ni2P)

Author

Britvin, Sergey N., primary, Murashko, Michail N., additional, Vapnik, Yevgeny, additional, Polekhovsky, Yury S., additional, Krivovichev, Sergey V., additional, Krzhizhanovskaya, Maria G., additional, Vereshchagin, Oleg S., additional, Shilovskikh, Vladimir V., additional, and Vlasenko, Natalia S., additional

Published
2020
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130. High-temperature Fe oxidation coupled with redistribution of framework cations in lobanovite, K Na(Fe Mg Na)Ti (Si O ) O (OH) – the first titanosilicate case

Author

Zhitova, Elena S., Zolotarev, Andrey A., Hawthorne, Frank C., Krivovichev, Sergey V., Yakovenchuk, Viktor N., and Goncharov, Alexey G.

Subjects
Bond strength, Chemistry, Crystal chemistry, Metals and Alloys, Atmospheric temperature range, engineering.material, 010502 geochemistry & geophysics, 010403 inorganic & nuclear chemistry, 01 natural sciences, Atomic and Molecular Physics, and Optics, Thermal expansion, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Crystallography, Astrophyllite, Octahedron, Materials Chemistry, engineering, Dehydrogenation, Redistribution (chemistry), 0105 earth and related environmental sciences
Abstract

The high-temperature (HT) behaviour of lobanovite, K Na(Fe Mg Na)Ti (Si O ) O (OH) , was studied using powder X-ray diffraction in the temperature range 25–1000°C and single-crystal X-ray diffraction of 17 crystals quenched from different temperatures. HT iron oxidation associated with dehydroxylation starts at 450°C, similar to other ferrous-hydroxy-rich heterophyllosilicates such as astrophyllite and bafertisite. A prominent feature of lobanovite HT crystal chemistry is the redistribution of Fe and Mg+Mn cations over the (2), (3), (4) sites of the octahedral ( ) layer that accompanies iron oxidation and dehydroxylation. This HT redistribution of cations has not been observed in titanosilicates until now, and seems to be triggered by the need to maintain bond strengths at the apical oxygen atom of the TiO pyramid in the heteropolyhedral ( ) layer during oxidation–dehydroxylation. Comparison of the HT behaviour of lobanovite with five-coordinated Ti and astrophyllite with six-coordinated Ti shows that the geometry of the Ti polyhedron plays a key role in the HT behaviour of heterophyllosilicates. The thermal expansion, geometrical changes and redistribution of site occupancies which occur in lobanovite under increasing temperature are reported. A brief discussion is given of minerals in which the cation ordering (usually for Fe and Mg) occurs together with iron oxidation–dehydroxylation at elevated temperatures: micas, amphiboles and tourmalines. Now this list is expanded by the inclusion of titanosilicate minerals.

Published
2019
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131. Perryite, (Ni,Fe)16PSi5, from the Mount Egerton aubrite: the first natural P-Si-ordered phosphide-silicide.

Author

BRITVIN, Sergey N., KRIVOVICHEV, Sergey V., VERESHCHAGIN, Oleg S., VLASENKO, Natalia S., SHILOVSKIKH, Vladimir V., KRZHIZHANOVSKAYA, Maria G., LOZHKIN, Maksim S., OBOLONSKAYA, Edita V., and KOPYLOVA, Yulia O.

Subjects
*SILICIDES, *ELECTRON probe microanalysis, *METEORITES, *ENSTATITE, *SOLAR system, *CRYSTAL structure
Abstract

Perryite, natural Ni-silicide, is a minor but regular constituent of the metal phase in enstatite chondrite (aubrite) and enstatite chondrite meteorites. Its synthetic analog was shown to have promising catalytic properties. The first-time solution of the crystal structure of natural perryite was completed on the material from the Mount Egerton aubrite. The mineral is trigonal, R-3c, a = 6.6525(5), c = 37.998(5) Å, V = 1456.3(3) and Z = 6. The structure was refined to R1 = 0.0137 based on 457 independent observed reflections. The chemical formula obtained from the structure refinement, (Ni14.14Fe1.88)S16.02PSi5, agrees with that derived from the electron microprobe data, (Ni13.39Fe2.65Co0.01)S16.05P1.22Si4.74. This research showed that P and Si in perryite are ordered, resulting in the simplified formula (Ni,Fe)16PSi8, in contrast to the currently accepted variant (Ni,Fe)8(Si,P)3. The detailed results of EBSD study reveal previously unknown relationships between perryite, associated a-(Fe,Ni) metal (also known as kamacite) and schreibersite, (Fe,Ni)3P. Since enstatitic meteorites represent the early stages of nebular accretion, our results demonstrate that the crystal-chemical factor could affect the differentiation of chemical elements upon the onset of the Solar System formation. [ABSTRACT FROM AUTHOR]

Published
2021
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132. Trigonal variation in the garnet supergroup: the crystal structure of nikmelnikovite, Ca12Fe2+Fe3+3Al3(SiO4)6(OH)20, from Kovdor massif, Kola Peninsula, Russia.

Author

Krivovichev, Sergey V., Panikorovskii, Taras L., Yakovenchuk, Victor N., Selivanova, Ekaterina A., and Ivanyuk, Gregory Yu.

Subjects
*CRYSTAL structure, *MINERALS, *UNIT cell, *PENINSULAS, *CHEMICAL species, *GARNET
Abstract

The crystal structure of nikmelnikovite, Ca12Fe2+Fe3+3Al3(SiO4)6(OH)20, a new member of the garnet supergroup from Kovdor massif, Kola Peninsula, Russia (R $\bar{3}$ , a = 17.2072(6), c = 10.5689(4) Å, V = 2710.1(2) Å3 and Z = 3) has been refined to R1 = 0.046 on the basis of 1184 unique observed reflections. Nikmelnikovite is the first mineral species in the garnet supergroup that has a trigonal (rhombohedral) symmetry. The relationship between its unit cell and the pseudocubic (ideal garnet) unit cell can be described by the transformation matrix [1 $\bar{1}$ 0 | 01 $\bar{1}$ | ½½½]. The crystal-chemical relations between the ideal Ia $\bar{3}$ d garnet and the nikmelnikovite structure type can be described by the following series of imaginary modifications: (1) the symmetry is lowered according to the Ia $\bar{3}$ d → R $\bar{3}$ group–subgroup relationship; (2) the cation sites are split according to the following sequences: X → {X1, X2}; Y → {Y1, Y2, Y3, Y4}; Z → {Z1, Z2}; (3) the X sites remain fully occupied by Ca; (4) each Y site is occupied predominantly by a distinct chemical species: Y1 → Al (Al site), Y2 → Fe2+ (Fe1 site), Y3 → Fe3+ (Fe2 site), Y4 → vacancy (Mn site); (5) one of the Z sites (Z1) is occupied by Si, whereas the other site (Z2) is predominantly vacant. The crystal-chemical formula that takes into account the transition between the archetype and the nikmelnikovite structure type can be described as X{Ca12}Y[Fe2+Al4Fe3+2□]Z(Si6□6)O24(OH)20□4. The structural complexity of nikmelnikovite (4.529 bit/atom and 434.431 bit/cell, after H-correction) is higher than those for andradite, grossular and katoite, which is typical for low-temperature minerals formed after primary minerals with simpler structures. [ABSTRACT FROM AUTHOR]

Published
2021
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135. Rb2CaCu6(PO4)4O2, a novel oxophosphate with a shchurovskyite-type topology: synthesis, structure, magnetic properties and crystal chemistry of rubidium copper phosphates

Author

Aksenov, Sergey M., primary, Borovikova, Elena Yu., additional, Mironov, Vladimir S., additional, Yamnova, Natalia A., additional, Volkov, Anatoly S., additional, Ksenofontov, Dmitry A., additional, Gurbanova, Olga A., additional, Dimitrova, Olga V., additional, Deyneko, Dina V., additional, Zvereva, Elena A., additional, Maximova, Olga V., additional, Krivovichev, Sergey V., additional, Burns, Peter C., additional, and Vasiliev, Alexander N., additional

Published
2019
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136. Dritsite, Li2Al4(OH)12Cl2·3H2O, a New Gibbsite-Based Hydrotalcite Supergroup Mineral

Author

Zhitova, Elena S., primary, Pekov, Igor V., additional, Chaikovskiy, Ilya I., additional, Chirkova, Elena P., additional, Yapaskurt, Vasiliy O., additional, Bychkova, Yana V., additional, Belakovskiy, Dmitry I., additional, Chukanov, Nikita V., additional, Zubkova, Natalia V., additional, Krivovichev, Sergey V., additional, and Bocharov, Vladimir N., additional

Published
2019
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148. Vasilseverginite, Cu9O4(AsO4)2(SO4)2, a new fumarolic mineral with a hybrid structure containing novel anion-centered tetrahedral structural units.

Author

Pekov, Igor V., Britvin, Sergey N., Krivovichev, Sergey V., Yapaskurt, Vasiliy O., Vigasina, Marina F., Turchkova, Anna G., and Sidorov, Evgeny G.

Subjects
MINERALS, TETRAHEDRA, CRYSTAL structure, UNIT cell, INORGANIC chemistry, TETRAHEDRAL molecules, ZINC oxide
Abstract

The new mineral vasilseverginite, ideally Cu9O4(AsO4)2(SO4)2, was found in the Arsenatnaya fumarole at the second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with tenorite, lammerite, stranskiite, lammerite-β, langbeinite, dolerophanite, sanidine, hematite, and gahnite. Vasilseverginite occurs as prismatic crystals up to 0.02 × 0.02 × 0.06 mm3 combined in groups or interrupted crusts up to 1 × 2 cm2 in area and up to 0.1 mm thick. It is transparent, bright green, with vitreous luster. Dcalc is 4.41 g⋅cm–3. Vasilseverginite is optically biaxial (–), α 1.816(5), β 1.870(5), γ 1.897(5), estimated 2V is 30(15)°. Chemical composition (wt%, electron-microprobe) is: CuO 64.03, ZnO 0.79, Fe2O3 0.25, P2O5 0.05, As2O5 20.83, SO3 14.92, total 100.87. The empirical formula calculated on O = 20 apfu is C u 8.78 Z n 0.11 F e 0.03 3 + Σ 8.92 A s 1.98 P 0.01 S 2.03 O 20 $\left(\mathrm{Cu}_{8.78} \mathrm{Zn}_{0.11} \mathrm{Fe}_{0.03}^{3+}\right)_{\Sigma 8.92} \mathrm{As}_{1.98} \mathrm{P}_{0.01} \mathrm{~S}_{2.03} \mathrm{O}_{20}$. Vasilseverginite is monoclinic, P21/n, a = 8.1131(4), b = 9.9182(4), c = 11.0225(5) Å, β = 110.855(2)°, V = 828.84(6) Å3, and Z = 2. The strongest reflections in the powder XRD pattern [d,Å(I)(hkl)] are: 7.13(41)(101̅), 5.99(70)(110, 111̅), 5.260(100)(101), 4.642(46)(111), 3.140(31)(031̅), 2.821(35)(023̅), 2.784(38)(132̅, 032̅), 2.597(35)(204̅), and 2.556(50) (231̅, 212). The crystal structure, solved using single-crystal X‑ray diffraction data, R1 = 0.025, is based upon complex [O4Cu9]10+ layers parallel to (101̅) that are composed of edge- and corner-sharing (OCu4) tetrahedra. The topology is unprecedented in inorganic structural chemistry. The crystal structure can be considered a hybrid of the structures of popovite Cu5O2(AsO4)2 and dolerophanite Cu2O(SO4) according to the scheme Cu9O4(AsO4)2(SO4)2 = Cu5O2(AsO4)2 + 2Cu2O(SO4). The chemical hybridization does not result in a significant increase in chemical complexity of vasilseverginite compared to the sum of those of popovite and dolerophanite, whereas the structural hybridization leads to the doubling of structural information per unit cell. The mineral is named in memory of the outstanding Russian mineralogist, geologist, and chemist Vasiliy Mikhailovich Severgin (1765–1826). [ABSTRACT FROM AUTHOR]

Published
2021
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149. Crystal chemistry of the M2+[(UO2)(T6+O4)2(H2O)](H2O)4 (M2+ = Mg, Mn, Fe, Co, Ni and Zn; T6+ = S, Se) compounds: the interplay between chemical composition, pH and structural architecture

Author

Kornyakov, Ilya V., Tyumentseva, Olga S., Krivovichev, Sergey V., Tananaev, Ivan G., and Gurzhiy, Vladislav V.

Abstract

Crystallization of the M2+[(UO2)(T6+O4)2(H2O)](H2O)4 (M2+ = Ni, Mg, Zn, Co, Fe and Mn; T6+ = S, Se) compounds is characterized by the presence of three different structure types, which are built by similar uranyl-based sulfate/selenate chains linked into pseudolayers through H-bonding networks, but the stacking sequences are different and can be described by the 1M, 2O and 2M polytypic modifications. In order to establish the interplay between chemical composition and structural architecture, eleven new Ni-bearing uranyl sulfate–selenate compounds have been synthesized, as well as a new Zn-bearing uranyl sulfate. To provide the extensive comparison of all the compounds, the crystal structures of previously studied Co and Mn uranyl sulfates of this family of compounds were re-investigated, which allowed reconsideration of their unit-cell parameters and the space-group symmetries. It is shown that crystallization of particular polytypes is governed by the interplay of the ionic radii of M2+ and T6+ cations, while pH of the initial solutions affects the rate of crystallization. [ABSTRACT FROM AUTHOR]

Published
2021
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