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The new mineral calcioveatchite, ideally SrCaB11O16(OH)5·H2O, is a Ca-Sr-ordered analogue of veatchite. It was found at the Nepskoe potassium salt deposit, Irkutsk Oblast, Siberia, Russia in halite-sylvite and sylvite-carnallite rocks, with boracite, hilgardite, kurgantaite, hydroboracite, volkovskite, veatchite, anhydrite, magnesite, and quartz. Calcioveatchite forms prismatic or tabular crystals up to 1 × 1.5 × 3 mm3 and crystal clusters up to 3 mm across. It is transparent and colourless with vitreous lustre. Calcioveatchite is brittle, cleavage is perfect on {010}, the Mohs' hardness is ca 2, Dmeas is 2.58(1), and Dcalc is 2.567 g cm−3. Calcioveatchite is optically biaxial (+), α = 1.543(2), β = 1.550(5), γ = 1.626(2), 2Vmeas = 30(10)°, and 2Vcalc = 35°. The average chemical composition (wt.%, electron microprobe, H2O calculated by stoichiometry) is: CaO 7.05, SrO 20.70, B2O3 61.96, H2O 10.22, and total 99.93. The empirical formula, calculated based on 22 O apfu = O16(OH)5(H2O) pfu, is Sr1.23Ca0.78B10.99O16(OH)5·H2O. Calcioveatchite is monoclinic, space group P21, a = 6.7030(3), b = 20.6438(9), c = 6.6056(3) Å, β = 119.153(7)°, V = 798.26(8) Å3, and Z = 2. Polytype: 1M. The strongest reflections of the powder XRD pattern [d,Å(I,%)(hkl)] are: 10.35(100)(020), 5.633(12)(110), 5.092(10)(120), 3.447(14)(060), 3.362(13)(101, 051), 3.309(38)(–102), 2.862(10)(012), and 2.585(19)(080). The crystal structure was solved based on single-crystal XRD data, R1 = 0.0420. Calcioveatchite (calcioveatchite-1M) is an isostructural analogue of veatchite-1M with the 11-fold cation polyhedron occupied mainly by Sr [Sr0.902(8)Ca0.098(8)] whereas the 10-fold polyhedron is Ca dominant [Ca0.686(7)Sr0.314(7)]. The chemical composition of veatchite from five localities in Russia (Nepskoe), Kazakhstan (Shoktybay and Chelkar in the North Caspian Region), and the USA (Tick Canyon and Billie Mine in California) was studied, and it is shown to exist in nature as a continuous, almost complete isomorphous series which extends from Ca-free veatchite, Sr2B11O16(OH)5·H2O, to calcioveatchite with the composition Sr1.14Ca0.87B10.99O16(OH)5·H2O. [ABSTRACT FROM AUTHOR]

Titanosilicates comprise a broad class of materials with promising technological applications. The typical obstacle that restricts their industrial applicability is the high manufacturing cost due to the use of specific organotitanium precursors. We herein report a new approach to the synthesis of titanosilicates using an inexpensive inorganic precursor, ammonium titanyl sulfate (ATS or STA), (NH4)2TiO(SO4)2∙H2O. The latter is an intermediate in the processing of titanium-bearing concentrates produced from apatite-nepheline ores. In this paper, the new synthetic approach is exemplified by the microwave-assisted synthesis of IONSIVE-911, one of the most effective Cs-ion scavengers. The method can be modified to synthesize various titanosilicate compounds. [ABSTRACT FROM AUTHOR]

Yakubovichite, CaNi2Fe3+(PO4)3, a new mineral containing up to 20 wt% NiO, represents a novel type of terrestrial phosphate mineralization featuring an extreme enrichment in Ni. The mineral was discovered in the Hatrurim Formation (Mottled Zone)—pyrometamorphic complex whose outcrops are exposed in Israel and Jordan in the area coincident with the Dead Sea Transform fault system. Nickel-rich minerals in these assemblages also include Ni phosphides: halamishite Ni5P4, negevite NiP2, transjordanite and orishchinite—two polymorphs of Ni2P, nazarovite Ni12P5, polekhovskyite MoNiP2; Ni-spinel trevorite NiFe2O4, bunsenite NiO, and nickeliferous members of the hematite-eskolaite series, Fe2O3-Cr2O3 containing up to 2 wt% NiO. Yakubovichite forms polycrystalline segregations up to 0.2 mm in size composed of equant crystal grains, in association with crocobelonite, hematite, other phosphates, and phosphides. It has a deep yellow to lemon-yellow color, is transparent to translucent with vitreous luster, and has no cleavage. Mohs hardness = 4. Yakubovichite is orthorhombic, Imma, unit-cell parameters of the holotype material: a = 10.3878(10), b = 13.0884(10), c = 6.4794(6) Å, V = 880.94(2) Å3, Z = 4. Chemical composition of holotype material (electron microprobe, wt%): Na2O 1.82, K2O 1.76, CaO 6.37, SrO 0.49, BaO 1.37, MgO 2.13, NiO 21.39, CuO 0.16, Fe2O3 18.80, Al2O3 1.06, V2O3 0.44, Cr2O3 0.15, P2O5 44.15, total 100.09. The empirical formula calculated on the basis of 12 O atoms per formula unit is (Ca0.55Na0.29K0.18Ba0.04Sr0.02)1.08(Ni1.39Mg0.26Fe30.24+ V30.03+ Cu0.01Cr0.01)Σ1.94 (Fe30.90+ Al0.10)Σ1P3.02O12. Dcalc = 3.657 g cm–3. The strongest lines of powder XRD pattern [d(Å)(I)(hkl)]: 5.82(44)(011), 5.51(73)(101), 5.21(32)(200), 4.214(34)(121), 2.772(97)(240), 2.748(100)(202), 2.599(38)(400). Yakubovichite is the first mineral that crystallizes in the α-CrPO4 structure type. It has a direct synthetic analog, CaNi2Fe3+(PO4)3. Since yakubovichite is the first natural Ni-phosphate of non-meteoritic origin, the possible sources of Ni in the reported mineral assemblages are discussed. Pyrometamorphic rocks of the Hatrurim Formation were formed at the expense of the sediments belonging to a Cretaceous-Paleogene (Cretaceous-Tertiary) boundary (~66 Ma age). This geological frame marks the event of mass extinction of biological species on Earth that was likely caused by the Chicxulub impact event. The anomalous enrichment of pyrometamorphic assemblages in Ni may be related to metamorphic assimilation of Ni-rich minerals accumulated in the Cretaceous-Paleogene layer, which was formed due to a Chicxulub collision. [ABSTRACT FROM AUTHOR]

Crocobelonite, CaFe23+(PO4)2O, is a new natural oxyphosphate discovered in the pyrometamorphic complexes of the Hatrurim Formation in Israel and Jordan. Crocobelonite-bearing assemblages contain a series of anhydrous Fe-Ni phosphates, hematite, diopside, anorthite, and phosphides—barringerite Fe2P, transjordanite Ni2P, murashkoite FeP, halamishite Ni5P4, and negevite NiP2. Crocobelonite forms submillimeter-sized aggregates of prismatic to acicular crystals of saffron-red to pinkish-red color. There are two polymorphic modifications of the mineral whose structures are interrelated by the unit-cell twinning. Crocobelonite-2O is orthorhombic, Pnma, a = 14.2757(1), b = 6.3832(1), c = 7.3169(1) Å, V 666.76(1) Å3, Z = 4. This polymorphic modification is isotypic with synthetic oxy-phosphates A V 2 3 + P O 4 2 O where A = Ca, Sr, Cd. The crystal structure has been refined to RB = 0.71% based on powder XRD data, using the Rietveld method and the input structural model obtained from the single-crystal study. Chemical composition (electron microprobe, wt%) is: CaO 16.03, MgO 0.56, Fe2O3 43.37, Al2O3 0.33, SiO2 0.32, P2O5 39.45, Total 100.06. The empirical formula based on O = 9 apfu is C a 1.02 F e 1.94 3 + M g 0.05 A l 0.02 2.01 P 1.98 S i 0.02 2.00 O 9.00 The strongest lines of powder XRD pattern [d(Å)(I)(hkl)] are: 6.54(16)(200), 5.12(26)(201), 3.549(100)(102), 3.200(50) (401), 2.912(19)(220), 2.869(40)(411), 2.662(21)(501). Crocobelonite- 1M is monoclinic, P21/m, a = 7.2447(2), b = 6.3832(1), c = 7.3993(2) Å, β = 106.401(2)°, V = 328.252(14) Å3, Z = 2. This polymorphic modification does not have direct structural analogs. Its crystal structure has been solved and refined based on the single-crystal data to R1 = 1.81%. Chemical composition is: CaO 15.56, MgO 0.16, NiO 0.78, Fe2O3 41.28, Al2O3 0.45, V2O3 0.42, Cr2O3 0.23, TiO2 0.79, P2O5 39.94, Total 99.61, corresponding to the empirical formula (O = 9 a p f u) C a 0.99 F e 1.85 3 + N i 0.04 T i 0.04 A l 0.03 V 0.02 3 + C r 0.01 M g 0.01 2.00 P 2.01 O 9.00 with Dcalc = 3.604 g/cm3. The strongest lines of powder XRD pattern [d(Å)(I)(hkl)] are 6.98(17)(100), 4.40(22)(101), 3.547(100)(201), 3.485(21)(200), 3.195(50)(020), 2.855(38)(102), 2.389(33)(122). Crocobelonite represents a novel type of phosphate mineral formed by oxidation of phosphide minerals at temperatures higher than 1000 °C and near-atmospheric pressure (pyrolytic oxidation). [ABSTRACT FROM AUTHOR]

A new mineral, hanauerite, ideally AgHgSI, was found in the oxidation zone of Ag- and Hg-bearing ores at two old, abandoned mines in Rhineland-Palatinate, Germany. In a holotype specimen originating from the Schöne Aussicht Mine, Dernbach, Westerwald, it is associated with plumbogummite–hinsdalite series of minerals and goethite. In cotype from the Friedrichssegen Mine, Bad Ems, it is associated with perroudite, goethite, and quartz. At both localities, hanauerite occurs as a prismatic crystal up to 0.15 mm long and up to 0.02 mm thick. The mineral is yellow, transparent, with an adamantine lustre. It is brittle, and cleavage was not observed. The calculated density values are 6.671 and 6.575 g cm−3 for holotype and cotype, respectively. The empirical formulae calculated (from electron microprobe data) based on the sum of all atoms = 4 apfu are Ag0.95Hg1.00S1.01(I0.83Br0.19Cl0.03)Σ1.05 for holotype and Ag0.97Hg0.97S1.05(I0.76Br0.25)Σ1.01 for cotype. Hanauerite is orthorhombic, space group Pmma; the unit cell parameters (from single-crystal X-ray diffraction data; holotype/cotype) are: a = 9.932(2)/9.9256(8), b = 4.6219(19)/4.6209(2), c = 9.891(4)/9.9006(4) Å, V = 454.0(3)/454.19(5) Å3, and Z = 4. The crystal structure was studied on single crystals extracted from both holotype and cotype specimens; R1 = 0.0416 (holotype) and =0.0544 (cotype). In hanauerite, Hg2+ cations centre strongly distorted octahedra with two short Hg–S bonds (Hg and S atoms build "crankshaft-type" chains) and four strongly elongated Hg–I bonds. The Hg-centred octahedra are connected via common edges and faces to form corrugated layers; Ag+ cations are located between these layers. Hanauerite is named in honour of the German mineral collector Dr. Alfred Hanauer (1912–1988). The common crystal chemical features of mercury sulphohalide minerals are discussed. [ABSTRACT FROM AUTHOR]

Ryabchikovite, ideally CuMg(Si2O6), a new pyroxene-group mineral (IMA No. 2021-011) was discovered in exhalations of the active Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia. The associated minerals are diopside, hematite, cuprospinel, fluorophlogopite, anhydrite, johillerite, tilasite, and aphthitalite-group sulfates. Ryabchikovite forms thin (up to 25 μm), light brown to reddish-brown epitactic crusts on short-prismatic brownish-gray crystals of diopside (up to 0.5 mm). The new mineral is optically biaxial (+), α = 1.685(5), β = 1.690(5), γ = 1.703(4), and 2V (meas) = 60(15)°. The average chemical composition (wt%, electron microprobe data) is: MgO 18.05, CaO 0.77, CuO 26.46, ZnO 2.23, Al2O3 0.93, Fe2O3 1.89, SiO2 50.10, total 100.43. The empirical formula calculated based on 6 O atoms per formulas unit is M g 1.05 C u 0.78 Z n 0.06 F e 0.06 3 + C a 0.03 S i 1.96 A l 0.04 O 6 Electron backscattered diffraction and powder X-ray difraction show that ryabchikovite is a Cu,Mg-ordered analog of clinoenstatite. Ryabchikovite adopts the space group P21/с and has the following unit-cell parameters: a = 9.731(9), b = 8.929(8), c = 5.221(4) Å, β = 110.00(6)°, V = 426.3(7) Å3, and Z = 4. Ryabchikovite is named in honor of the outstanding Russian geochemist and petrologist Igor Dmitrievich Ryabchikov (1937–2017). Our studies reveal that copper analogs of rock-forming minerals could be found in fumarolic systems. Their crystallization does not require high temperatures or/and pressures (below 500 °C/Pa). [ABSTRACT FROM AUTHOR]

The new mineral nishanbaevite, ideally KAl2O(AsO4)(SO4), was found in sublimates of 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 euchlorine, alumoklyuchevskite, langbeinite, urusovite, lammerite, lammerite-β, ericlaxmanite, kozyrevskite, and hematite. Nishanbaevite occurs as long-prismatic or lamellar crystals up to 0.03 mm typically combined in brush-like aggregates and crusts up to 1.5 mm across. It is transparent, colourless, with vitreous lustre. Dcalc = 3.012 g cm− 3. Nishanbaevite is optically biaxial (–), α = 1.552, β ≈ γ = 1.567. The chemical composition (average of seven analyses) is: Na2O 3.79, K2O 8.01, CaO 0.10, CuO 0.21, Al2O3 30.08, Fe2O3 0.50, SiO2 1.62, P2O5 0.66, As2O5 32.23, SO3 22.59, total 99.79 wt%. The empirical formula calculated based on 9 O apfu is: (K0.57Na0.41Ca0.01)Σ0.99(Al1.99Fe3+0.02Cu0.01)Σ2.02(As0.95S0.95Si0.09P0.03)Σ2.02O9. Nishanbaevite is orthorhombic, Pbcm, a = 15.487(3), b = 7.2582(16), c = 6.6014(17) Å, V = 742.1(3) Å3 and Z = 4. The strongest reflections of the powder XRD pattern [d,Å(I)(hkl)] are: 15.49(100)(100), 6.56(30)(110), 4.653(29)(111), 3.881(54)(400), 3.298(52)(002), 3.113(29)(121), and 3.038(51)(202, 411). The crystal structure, solved from single-crystal XRD data (R = 7.58%), is unique. It is based on the complex heteropolyhedral sheets formed by zig-zag chains of Al-centred polyhedra (alternating trigonal bipyramids AlO5 and octahedra AlO6 sharing edges) and isolated tetrahedra AsO4 and SO4. Adjacent chains of Al polyhedra are connected via AsO4 tetrahedra to form a heteropolyhedral double-layer. Its topological peculiarity is considered and compared with those in structurally related compounds. The (K,Na) site is located in the interlayer space between SO4 tetrahedra. The position of nishanbaevite among the arsenate-sulfates and their specific structural features are discussed. The mineral is named in honour of the Russian mineralogist Tursun Prnazorovich Nishanbaev (1955–2017). [ABSTRACT FROM AUTHOR]

Zaykovite, ideally Rh3Se4, is a new mineral, the first natural rhodium selenide. It was discovered in the assemblages of platinum-group minerals from the Kazan gold placer, South Urals, Russia. The mineral occurs as crystals up to 40 μm in size within the grains of Pt3Fe alloy, in association with unnamed Pd–Sb–Te phase and Au–Pd alloy. In reflected light, zaykovite has a grey colour with bluish-greenish tint; it shows weak bireflectance and anisotropy. Reflectance values [ R max/ R min (%) for COM approved wavelengths (nm)] are: 30.1/29.3(470), 32.2/31.0(546), 33.4/32.0(589) and 35.1/33.7(650). The chemical composition corresponds to the empirical formula (Rh2.26Pt0.46Ir0.25Ru0.01Pd0.01Fe0.01)Σ3.00(Se2.77S1.21Te0.02)Σ4.00 Zaykovite is monoclinic, space group C 2/ m , a = 10.877(1), b = 11.192(1), c = 6.4796(6) Å, β = 108.887(2)°, V = 746.3(1) Å3, Z = 6 and D calc = 8.32 g cm–1. The crystal structure has been solved and refined to R 1 = 0.016 based on 858 unique observed reflections. The strongest lines of the powder X-ray diffraction pattern [ d (Å), (I), (hkl)] are: 5.43(37)($\bar{1}$ 11), 3.275(75)(310), 3.199(100)($\bar{1}$ 31), 3.061(87)(002), 2.568(62)(400), 2.545(41)(041), 3.413(34)($\bar{2}$ 41) and 1.697(34)(441). Zaykovite is a Se analogue of kingstonite, Rh3S4. A continuous series of solid solutions between kingstonite and zaykovite was encountered in the samples from the Kazan placer. The possible sources of this unique Rh–Se mineralisation in the South Urals could be serpentinised dunite–harzburgite or gabbro–clinopyroxenite–dunite complexes in the vicinity. [ABSTRACT FROM AUTHOR]