An aromatic ligand was introduced into the synthesis of a uranyl peroxide polyoxometalate formulated as K32(UO2)19(O2)26(OH)2­(C6H4P2O6)4·65H2O that consists of a unique “open oyster” shaped structure (U19) with intramolecular H-bonds. In the solid state, K−π and π–π interactions as well as K–O bonds enable the formation of a supramolecular network between U19 clusters. U19 adopts an incomplete fullerene topology and was utilized as a precursor from which the geometrically favored U24 structure was produced. A potassium-encapsulated U24 structure was obtained upon heating the solution containing U19.

The bismuth(III) oxophosphate Bi(PO)O was obtained by hydrothermal synthesis. The unit cell has a = 5.6840(6) Å, b = 7.0334(7) Å, c = 9.1578(9) Å, α = 78.958(2)°, β = 77.858(2)°, γ = 68.992(2)°, V = 331.41(6) Å, space group P1̅, and Z = 2. The crystal chemical formula that reflects the presence of oxo-centered tetrahedra and triangles is [OOBi](PO). The crystal structure contains [OBi]-heteropolyhedral corrugated layers parallel to (001), which alternate along [001] with isolated (PO) tetrahedra. The structural complexity parameters are v = 22 atoms, I = 3.459 bits/atoms, and I = 76.107 bits/unit cell, and thus Bi(PO)O is the simplest pure bismuth(III) oxophosphate.

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Paddlewheelite, MgCa 5 Cu 2 [(UO 2 )(CO 3 ) 3 ] 4 ·33H 2 O, is a new uranyl carbonate mineral found underground in the Svornost mine, Jáchymov District, Bohemia, Czech Republic, where it occurs as a secondary oxidation product of uraninite. The conditions leading to its crystallization are complex, likely requiring concomitant dissolution of uraninite, calcite, dolomite, chalcopyrite, and andersonite. Paddlewheelite is named after its distinctive structure, which consists of paddle-wheel clusters of uranyl tricarbonate units bound by square pyramidal copper "axles" and a cubic calcium cation "gearbox." Paddle wheels share edges with calcium polyhedra to form open sheets that are held together solely by hydrogen bonding interactions. The new mineral is monoclinic, Pc, a = 22.052(4), b = 17.118(3), c = 19.354(3) Å, β = 90.474(2) • , V = 7306(2) Å 3 and Z = 4. Paddlewheelite is the second-most structurally complex uranyl carbonate mineral known after ewingite and its structure may provide insights into the insufficiently described mineral voglite, as well as Cu-U-CO 3 equilibrium in general.the surface of used nuclear fuel exposed to groundwater. Uranyl carbonate minerals can record and be used to diagnose groundwater conditions at the moment of crystallization, allowing for more accurate safety assessments of U contaminated water transport and longer-term radionuclide release models for Ca-U-C systems. Here we describe the crystal-chemical and spectroscopic properties of the new Ca-Mg-Cu uranyl carbonate mineral paddlewheelite, whose structure contains several first known instances for uranyl minerals, including isolated square pyramidal copper polyhedra and calcium cations in cubic coordination. These two unique cation polyhedra bind to UTC units, forming an extraordinary paddlewheel motif arranged into an open-sheet topology that may provide several clues to understanding the structure and formation of the poorly described mineral voglite,The name paddlewheelite was chosen to reflect the unique structure of the mineral that resembles the paddlewheel of a steamboat. Four uranyl tricarbonate paddles are bound by two square pyramidal CuO 5 "axles" and a CaO 8 "gearbox" in cubic coordination. The new mineral and its name were approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA2017-098). The holotype specimen is deposited in the Natural History Museum of Los Angeles County, under catalogue number 66696. OccurrenceCrystals of paddlewheelite were collected underground from a bifurcation of the Prokop vein on the 5th level of the Svornost mine, Jáchymov District, Bohemia, Czech Republic. The Svornost mine (Einigkeit in German, Concord in English) is named for one of the six major ore clusters in the Jáchymov ore district. "Five-element" (Ni-Co-As-Ag-Bi, +/− U) mineralization was deposited there during episodic fracturing and space filling by metal-rich hydrothermal solutions. Further details regarding the geology and hydrothermal history of the J...

The Jocão pegmatite (or Cigana) is located in the well-known Eastern Brazilian Pegmatitic Province (EBPP), Minas Gerais, Brazil. According to their macroscopic textures, three different kinds of phosphate mineral masses were collected from the dumps of the pegmatite: association I is composed of dendritic triphylite, forming intergrowths with silicate minerals (spessartine garnet or albite); association II forms blocky nodules of triphylite-ferrisicklerite-heterosite; and association III shows exsolution lamellae of ferrisicklerite-heterosite in massive beusite. The primary textures and the Fe/(Fe+Mn) ratios of primary triphylite make it possible to establish the crystallization sequence of the primary phases; the petrogenesis of primary intergrowths between garnet and triphylite of association I is also discussed. In the three associations, these primary minerals are hydrothermally altered and secondary species are produced. In association I, the first hydrothermal alteration event was a weakly oxidizing hydroxylation stage, during which triphylite was only replaced by hureaulite (rarely associated with barbosalite) along its cleavage planes. The final stage affecting association I corresponds to meteoric processes during which ludlamite and then vivianite progressively replaced triphylite. Association II evolved under more oxidizing conditions and the first alteration stage corresponds to the progressive oxidation of triphylite accompanied by Li-leaching, leading to ferrisicklerite and heterosite. The second hydrothermal stage corresponds to a hydroxylation event, and the secondary species depend on the phosphate mineral that they replace: triphylite is only altered to Fe 2+ -Mn 2+ -bearing hydrated species (colorless hureaulite); ferrisicklerite is altered to Fe 2+ -, Mn 2+ -, and Fe 3+ -bearing phosphate minerals such as jahnsite s.l., frondelite s.l., and orange hureaulite; heterosite is replaced by Fe 3+ -bearing species such as ferristrunzite. Consequently, it appears that the secondary phosphate minerals, which crystallize during this second hydrothermal stage, strongly depend on the cations which are locally available in the sample zone. The final stage forms the meteoric species: leucophosphite and phosphosiderite directly replace heterosite, whereas vivianite, a ferrous meteoric species, only appears in the triphylite core. In association III, exsolution lamellae are formed at the expense of a high-temperature homogenous Ca-Li-bearing graftonite-beusite-like phase; when the temperature decreased, Li migrated into triphylite and Ca to the larger M1 site of beusite. During the high-temperature hydrothermal alteration processes, triphylite transforms into ferrisicklerite and heterosite, like in association II; however, beusite is not affected by any transformation process at that stage. During the low temperature hydroxylation stage, ferrisicklerite from the core remains almost unaltered, while beusite is replaced by an intimate mixture of pleochroic Ca-rich hureaulite and tavorite. After this hydroxylati...