ALBERT

Description: The investigation of elemental composition, crystal structure and thermal behavior of vonsenite and hulsite from the Titovskoe boron deposit in Russia is reported. The structures of the borates are described in terms of cation-centered and oxocentred polyhedra. There are different sequences of double chains and layers consisting of oxocentred [OM 4] n + tetrahedra and [OM 5] n + tetragonal pyramids forming a framework. Elemental composition was determined by energy-dispersive X-ray spectroscopy (EDX). Oxidation states and coordination sites of iron and tin in the oxoborates are determined using Mössbauer spectroscopy and compared with EDX and X-ray diffraction data (XRD). According to results obtained from high-temperature Mössbauer spectroscopy, the Fe2+ to Fe3+ oxidation in vonsenite and hulsite occurs at approximately 500 and 600 K, respectively. According to the high-temperature XRD data, this process is accompanied by an assumed deformation of crystal structures and subsequent solid-phase decomposition to hematite and warwickite. It is seen as a monotonic decrease of volume thermal expansion coefficients with an increase in temperature. A partial magnetic ordering in hulsite is observed for the first time with T c ≃ 383 K. Near this temperature, an unusual change of thermal expansion coefficients is revealed. Vonsenite starts to melt at 1571 K and hulsite melts at 1504 K. Eigenvalues of thermal expansion tensor are calculated for the oxoborates as well as anisotropy of the expansion is described in comparison with their crystal structures.

Description: A review of the crystal chemistry of Fe-deficient eudialyte-group minerals is given. Specific features of cation distribution over key sites in the crystal structure, including partial substitution of Fe2+ with Na, Mn and Zr at the M2 site are discussed. It is concluded that Na-dominant (at the M2 site) eudialyte-group members (M2Na-EGMs) are markers of specific kinds of specific peralkaline (hyperagpaitic) igneous rocks and pegmatites. New data are obtained on the chemical composition, IR spectra and crystal chemistry for two samples of M2Na-EGMs with disordered M1 cations, which are a potentially new mineral species with the simplified formula (Na,H2O)15Ca6Zr3[Na2(Fe,Zr)][Si26O72](OH)2Cl·nH2O.

Description: 〈div data-abstract-type="normal"〉〈p〉The new durangite-group mineral arsenatrotitanite, ideally NaTiO(AsO〈span〉4〈/span〉), 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 orthoclase, tenorite, hematite, johillerite, bradaczekite, badalovite, calciojohillerite, arsmirandite, tilasite, svabite, cassiterite, pseudobrookite, rutile, sylvite, halite, aphthitalite, langbeinite and anhydrite. Arsenatrotitanite occurs as prismatic, tabular, lamellar or acicular crystals up to 0.3 mm × 0.8 mm × 2 mm. They are separated or combined in open-work aggregates up to 2 mm across or interrupted crusts up to 2 mm × 5 mm in area and up to 0.3 mm thick. Arsenatrotitanite is transparent, brownish red to pale pinkish-reddish or almost colourless, with vitreous lustre. It is brittle and the Mohs’ hardness is ~5½. Cleavage is perfect on {110} and the fracture is stepped. 〈span〉D〈/span〉〈span〉calc〈/span〉 is 3.950 g cm〈span〉–3〈/span〉. Arsenatrotitanite is optically biaxial (+), α = 1.825(5), β = 1.847(6), γ = 1.896(6) (589 nm) and 2V〈span〉meas.〈/span〉 = 70(5)°. Chemical composition (wt.%, electron-microprobe) is: Na〈span〉2〈/span〉O 12.26, CaO 3.10, Al〈span〉2〈/span〉O〈span〉3〈/span〉 4.39, Fe〈span〉2〈/span〉O〈span〉3〈/span〉 9.57, TiO〈span〉2〈/span〉 17.11, SnO〈span〉2〈/span〉 1.03, As〈span〉2〈/span〉O〈span〉5〈/span〉 50.17, F 3.29, O = F –2.39, total 99.53. The empirical formula based on 5 (O + F) apfu is (Na〈span〉0.91〈/span〉Ca〈span〉0.13〈/span〉)〈span〉Σ1.04〈/span〉(Ti〈span〉0.49〈/span〉Fe〈span〉3+〈/span〉〈span〉0.27〈/span〉Al〈span〉0.20〈/span〉Sn〈span〉0.02〈/span〉)〈span〉Σ0.98〈/span〉(As〈span〉1.00〈/span〉O〈span〉4.00〈/span〉)(O〈span〉0.60〈/span〉F〈span〉0.40〈/span〉). Arsenatrotitanite is monoclinic, 〈span〉C〈/span〉2/〈span〉c〈/span〉, 〈span〉a〈/span〉 = 6.6979(3), 〈span〉b〈/span〉 = 8.7630(3), 〈span〉c〈/span〉 = 7.1976(3) Å, β = 114.805(5)°, 〈span〉V〈/span〉 = 383.48(3) Å〈span〉3〈/span〉 and 〈span〉Z〈/span〉 = 4. The strongest reflections of the powder X-ray diffraction (XRD) pattern [〈span〉d〈/span〉,Å(〈span〉I〈/span〉)(〈span〉hkl〈/span〉)] are: 4.845(89)(〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190709073523038-0660:S0026461X18001342:S0026461X18001342_inline31.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉), 3.631(36)(021), 3.431(48)(111), 3.300(100)(〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190709073523038-0660:S0026461X18001342:S0026461X18001342_inline32.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉), 3.036(100)(200), 2.627(91)(130) and 2.615(57)(022). The crystal structure was solved from single-crystal XRD data with 〈span〉R〈/span〉 = 1.76%. Arsenatrotitanite belongs to the titanite/durangite structure type. It is named as an 〈span〉arsenat〈/span〉e of sodium (〈span〉natr〈/span〉ium in Latin) and 〈span〉titani〈/span〉um isostructural with 〈span〉titanite〈/span〉.〈/p〉〈/div〉

Description: Carlgieseckeite-(Nd), ideally NaNdCa3(PO4)3F, a new mineral species of the belovite group of the apatite supergroup, was found at the Kuannersuit Plateau, Ilímaussaq alkaline complex, South Greenland. It is associated with albite, analcime and fluorapatite in cavities of an albite vein cross-cutting augite syenite. Carlgieseckeite-(Nd) forms hexagonal tabular crystals up to 0.25 × 1 × 1.3 mm, and their parallel intergrowth up to 0.7 × 1.3 mm is found epitactically overgrown on prismatic crystals of fluorapatite. A phase with the idealized formula Na1.5Nd1.5Ca2(PO4)3F epitactically overgrows some crystals of carlgieseckeite-(Nd). Carlgieseckeite-(Nd) is transparent and shows a distinct color-change effect, from almost colorless with a greenish hue in daylight to pink in yellow electric light. The luster is vitreous. The Mohs hardness is ca. 5. The mineral is brittle with no observed cleavage and an uneven fracture. The calculated density is 3.91 g/cm3. Carlgieseckeite-(Nd) is optically negative, uniaxial [ω = 1.655(3), ɛ = 1.632(2)] or shows anomalous biaxiality [α 1.632(2), β 1.654(3), γ 1.656(3), 2V(meas.) 15(5)°]. The average chemical composition (electron-microprobe data) is: Na2O 5.68, CaO 18.53, SrO 7.55, BaO 0.14, La2O3 1.32, Ce2O3 10.60, Pr2O3 2.62, Nd2O3 15.08, Sm2O3 2.89, Gd2O3 0.52, SiO2 0.56, P2O5 32.72, F 2.80, Cl 0.06, −O=(F,Cl)2 −1.19, total 99.88 wt.%. The empirical formula calculated on the basis of 13 O + F + Cl apfu is: Na1.17Ca2.11Sr0.46Ba0.01La0.05 Ce0.41Pr0.10Nd0.57Sm0.11Gd0.02Si0.06P2.94O12.05F0.94Cl0.01. Carlgieseckeite-(Nd) is trigonal, space group P3̄, a 9.4553(1), c 6.9825(1) Å, V 540.62(1) Å3, Z = 2. The crystal structure was refined from X-ray-diffraction data (single crystal, R = 0.0218). Carlgieseckeite-(Nd) is the isostructural Ca- and Nd-dominant analogue of belovite-(Ce) and belovite-(La). The strongest lines of the powder X-ray pattern [d in Å (I)(hkl)] are: 7.02(22)(001), 5.33(18)(101), 3.923(27)(111), 3.463(23)(002), 3.095(19)(210), 2.815(100)(211,112), 2.727(42)(300). The mineral is named in honor of Carl Ludwig Giesecke (1761–1833), a mineralogist and polar explorer, the pioneer researcher of the mineralogy of Greenland. The Levinson suffix modifier -(Nd) is appropriate to express the dominance of Nd over other REE in the mineral. The holotype material is deposited in the Fersman Mineralogical Museum of Russian Academy of Sciences, Moscow.

Description: The new Mg- and F-dominant lamprophyllite-group mineral lileyite (IMA 2011-021) was found at the Löhley quarry, Üdersdorf, near Daun, Eifel Mountains, Rhineland-Palatinate (Rheinland-Pfalz), Germany, and named for the old name of the type locality, Liley. Associated minerals are nepheline, leucite, augite, magnetite, fluorapatite, perovskite, götzenite. Lileyite is brown, translucent; streak is white. It forms platy crystals up to 0.1 × 0.3 × 0.5 mm in size and their clusters up to 1 mm across on the walls of cavities in an alkaline basalt. Lileyite is brittle, with Mohs hardness of 3–4 and perfect cleavage on (001). Dcalc is 3.776 g/cm3. The new mineral is biaxial (+), a = 1.718(5), ß = 1.735(5), ? = 1.755(5), 2V (meas.) = 75(15)°, 2V (calc.) = 86°. The IR spectrum is given. The chemical composition is (EDS-mode electron microprobe, mean of 5 analyses, wt%): SiO2 28.05, BaO 26.39, TiO2 18.53, Na2O 6.75, MgO 4.58, FeO 4.48, CaO 2.30, SrO 2.23, MnO 1.44, K2O 1.41, Nb2O5 0.95, F 3.88, –O=F2 -1.63; total 99.36. The empirical formula based on 18 anions is: Ba1.50Sr0.19K0.26Na1.89Ca0.36Mn0.18Mg0.99Fe0.54Ti2.01Nb0.06Si4.06O16.23F1.77. The simplified formula is: Ba2(Na,Fe,Ca)3MgTi2(Si2O7)2O2F2. The crystal structure was solved using single-crystal X-ray diffraction data (R = 0.024). Lileyite is monoclinic, space group C2/m, a = 19.905(1), b = 7.098(1), c = 5.405(1) Å, ß = 96.349(5)°, V = 758.93(6) Å3, Z = 2. The strongest lines of the powder diffraction pattern [d, Å (I, %) (hkl)] are: 3.749 (45) (31–1), 3.464 (76) (510, 311, 401), 3.045 (37) (51–1), 2.792 (100) (221, 511), 2.672 (54) (002, 601, 20-2), 2.624 (43) (710, 42–1). Type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, registration number 4106/1.

Description: The new mineral langbanshyttanite was discovered in a specimen from the Langban mine (59.86{degrees}N, 14.27{degrees}E), Filipstad district, Varmland County, Bergslagen ore province, Sweden. Associated minerals are calcite, Mn-bearing phlogopite, spinels of the jacobsite-magnetite series, antigorite and trigonite. The mineral is named after the old name of the mine, smelter and mining village: Langbanshyttan. Langbanshyttanite is transparent, colourless. It occurs in late-stage fractures or corroded pockets, forming soft, radial and random aggregates (up to 1 mm) of acicular crystals up to 5 x 20 x 400 {micro}m. Dcalc is 3.951 g/cm3. The new mineral is biaxial (+), {alpha} = 1.700(5), {beta} = 1.741(5), {gamma} = 1.792(5), 2V (meas.) {approx} 90{degrees}, 2V (calc.) = 86{degrees}. Dispersion is strong, r 〈 v. The IR spectrum is given. The chemical composition is (electron microprobe, mean of five analyses, wt%): PbO 44.71, MgO 3.79, MnO 13.34, FeO 1.89, P2O5 0.65, As2O5 22.90, H2O (determined by gas chromatographic analysis of the products of ignition at 1200 {degrees}C) 14.4; total 101.68. The empirical formula based on 18 O atoms is: Pb1.97Mn1.85Mg0.93Fe0.26(AsO4)1.96(PO4)0.09(OH)3.87{middle dot}5.93H2O. The simplified formula is: Pb2Mn2Mg(AsO4)2(OH)4{middle dot}6H2O. Single-crystal diffraction data obtained using synchrotron radiation indicate that langbanshyttanite is triclinic, P[IMG]f1.gif" ALT="Formula" BORDER="0"〉, a = 5.0528(10), b = 5.7671(6), c = 14.617(3) A, {alpha} = 85.656(14), {beta} = 82.029(17), {gamma} = 88.728(13){degrees}, V = 420.6(2) A3, Z = 1, and is a representative of a new structure type. In the structure, edge-sharing MnO2(OH)4 octahedra form zig-zag columns that are linked by isolated AsO4 tetrahedra. Pb cations having six-fold coordination are located between the AsO4 tetrahedra. Isolated Mg(H2O)6 octahedra are located in the inter-block space. The strongest lines of the powder diffraction pattern [d, A (I, %) (hkl)] are: 14.48 (100) (001), 7.21 (43) (002), 4.969 (34) (100, 101), 4.798 (28) (003), 3.571 (54) (112, 1-1-1, 01-3, 11-1), 2.857 (45) (020, 021, 114), 2.800 (34) (11-3). Parts of the holotype specimen are deposited in the Fersman Mineralogical Museum of Russian Academy of Sciences, Moscow, Russia, with the registration number 4032/1 and in the collections of the Swedish Museum of Natural History, Stockholm, Sweden, under catalogue number NRM 20100076.

Description: 〈div data-abstract-type="normal"〉〈p〉Hydrotalcite, ideally [Mg〈span〉6〈/span〉Al〈span〉2〈/span〉(OH)〈span〉16〈/span〉](CO〈span〉3〈/span〉)(H〈span〉2〈/span〉O)〈span〉4〈/span〉, was studied in samples from Dypingdal, Snarum, Norway (3〈span〉R〈/span〉 and 2〈span〉H〈/span〉), Zelentsovskaya pit (2〈span〉H〈/span〉) and Praskovie–Evgenievskaya pit (2〈span〉H〈/span〉) (both Southern Urals, Russia), Talnakh, Siberia, Russia (3〈span〉R〈/span〉), Khibiny, Kola, Russia (3〈span〉R〈/span〉), and St. Lawrence, New York, USA (3〈span〉R〈/span〉 and 2〈span〉H〈/span〉). Two polytypes, 3〈span〉R〈/span〉 and 2〈span〉H〈/span〉 (both ‘classical’), were confirmed on the basis of single-crystal and powder X-ray diffraction data. Their chemical composition was studied by electron-microprobe analysis, infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The crystal structure of hydrotalcite-3〈span〉R〈/span〉 was solved by direct methods in the space group 〈span〉R〈/span〉〈span〉〈span〉〈img data-mimesubtype="gif" data-type="simple" src="http://static.cambridge.org/resource/id/urn:cambridge.org:id:binary:20190522072108342-0385:S0026461X18001457:S0026461X18001457_inline1.gif"〉 〈span data-mathjax-type="texmath"〉 〈/span〉 〈/span〉〈/span〉〈span〉m〈/span〉 on three crystals (two data collections at 290 K and one at 120 K). The unit-cell parameters are as follows (290/290/120 K): 〈span〉a〈/span〉 = 3.0728(9)/3.0626(3)/3.0617(4), 〈span〉c〈/span〉 = 23.326(9)/23.313(3)/23.203(3) Å and 〈span〉V〈/span〉 = 190.7(1)/189.37(4)/188.36(4) Å〈span〉3〈/span〉. The crystal structures were refined on the basis of 304/150/101 reflections to 〈span〉R〈/span〉〈span〉1〈/span〉 = 0.075/0.041/0.038. Hydrotalcite-2〈span〉H〈/span〉 crystallises in the 〈span〉P〈/span〉6〈span〉3〈/span〉/〈span〉mmc〈/span〉 space group; unit-cell parameters for two crystals are (data collection at 290 K and 93 K): 〈span〉a〈/span〉 = 3.046(1)/3.0521(9), 〈span〉c〈/span〉 = 15.447(6)/15.439(4) Å, 〈span〉V〈/span〉 = 124.39(8)/124.55(8) Å〈span〉3〈/span〉. The crystal structures were refined on the basis of 160/142 reflections to 〈span〉R〈/span〉〈span〉1〈/span〉 = 0.077/0.059. This paper reports the first single-crystal structure data on hydrotalcite. Hydrotalcite distribution in Nature, diagnostic features, polytypism, interlayer topology and localisation of 〈span〉M〈/span〉〈span〉2+〈/span〉–〈span〉M〈/span〉〈span〉3+〈/span〉 cations within metal hydroxide layers are discussed.〈/p〉〈/div〉

Description: A new pumpellyite-group mineral shuiskite-(Cr), ideally Ca2CrCr2[SiO4][Si2O6(OH)](OH)2O, was found at the Rudnaya mine, Glavnoe Saranovskoe deposit, Middle Urals, Russia. It occurs on the walls of 0.5 to 1 cm thick fractures in chromitite, filled with calcite, Cr-bearing clinochlore, and uvarovite. Shuiskite-(Cr) forms long prismatic to acicular crystals up to 0.1 × 0.5 × 7 mm elongated along [010] and slightly flattened on [100]. The crystals are commonly combined into radial, sheaf-like aggregates. Most observed crystals are simple twins with a (001) composition plane. Shuiskite-(Cr) is greenish-black under daylight or purplish-black under incandescent light. It is optically biaxial (–), α = 1.757(5), β = 1.788(6), γ = 1.794(6), 2V (meas.) = 45(10)°, 2V (calc.) = 46° (589 nm). The Dcalc is 3.432 g/cm3. The IR spectrum is reported. The chemical composition (wt.%) is CaO 21.33, MgO 3.17, Al2O3 5.41, Cr2O3 28.50, TiO2 0.18, SiO2 33.86, H2O 5.82, total 98.27. The empirical formula calculated based on the sum of eight metal cations and Si atoms per formula unit is Ca2.02Mg0.42Cr3+1.99Al0.56Ti0.01Si3.00O10.57(OH)3.43. The simplified formula is Ca2(Cr,Mg)(Cr,Al)2[SiO4][Si2O6(OH,O)](OH,O)(OH)2. Shuiskite-(Cr) is monoclinic, C2/m, a = 19.2436(6), b = 5.9999(2), c = 8.8316(3) Å, β = 97.833(3)°, V = 1010.17(6) Å3, and Z = 4. The crystal structure, solved from single-crystal X-ray diffraction data (R = 0.0469), is based on a pair of chains of edge-sharing Cr-centred octahedra running along the b axis, linked together via the [SiO4] and [Si2O6(OH)] groups and Ca-centred polyhedra. The mineral species shuiskite, ideally Ca2MgCr2[SiO4][Si2O6(OH)](OH)3, was renamed to shuiskite-(Mg) by the decision of the IMA CNMNC. The shuiskite solid solution series with the general formula Ca2XCr2[SiO4][Si2O6(OH,O)](OH)2(OH,O), which includes shuiskite-(Mg) and shuiskite-(Cr) with X = Mg and Cr3+, respectively, appeared in the pumpellyite group.

Description: Pseudolyonsite, ideally Cu3(VO4)2, is a new mineral from the medium-temperature fumaroles of the New Tolbachik scoria cones, Tolbachik volcano, Kamchatka Peninsula, Russia. It occurs as needles that are 5-20 {micro}m across and up to 0.5 mm in the length, which sometimes produce parallel intergrowths, sprays or openwork clusters up to 2 mm. Associated minerals are: piypite, hematite, magnetite, lyonsite, aphthitalite, palmierite, langbeinite, filatovite, lammerite, vergasovaite, rutile and native gold. Pseudolyonsite is dark red with a brownish tint to black, translucent to opaque, with a reddish-brown streak and adamantine to semi-metallic lustre. The mineral is brittle, but thin long needles are flexible. The fracture is conchoidal, and no cleavage was observed. The calculated density is 4.749 g/cm3. In reflected light in air the mineral is grey with a weak bluish tint, non-pleochroic, has distinct anisotropy and ubiquitous red to orange internal reflections. The reflectance values (R1 and R2, %) in air for the four COM wavelengths are, respectively, 17.05, 19.6 (470 nm); 16.1, 18.15 (546 nm); 15.85, 17.7 (589 nm); and 15.55, 17.4 (650 nm). Four electron probe (EDS) analyses produced the following mean values: V2O5 40.37, CuO 48.83, ZnO 7.60, MoO3 1.89, and SiO2 0.14, total 98.83 wt%, which corresponds, on the basis of 8 O atoms, to (Cu2.58Zn0.44){sum}3.02(V1.88Mo0.06Si0.02){sum}1.96O8. The idealised formula is Cu3(VO4)2. Pseudolyonsite is monoclinic: P21/c, a = 6.2695(4), b = 8.0195(3), c = 6.3620(3) A, {beta} = 111.96(1){degrees}, V = 296.66(3) A3, Z = 2. The strongest powder X-ray diffraction lines [d in A (I) (hkl)] are: 4.70 (60) (110); 3.30 (79) (021, 120); 3.22 (87) (111); 3.18 (34) (-121, -102); 2.894 (74) (200, -211); 2.761 (100) (012); 2.479 (59) (-212, -122); 2.419 (67) (031, 130). The crystal structure was solved from single-crystal data and refined to R = 0.0444. Pseudolyonsite is isostructural with synthetic monoclinic Cu3(VO4)2. The crystal structure of pseudolyonsite contains corrugated octahedral layers formed by the chains of edge-shared, distorted Cu(2)-octahedra running along the c axis and connected to each other by distorted Cu(1)-octahedra. The octahedra of both types contain Cu and subordinate Zn, and they are typically Jahn-Teller-distorted. Adjacent octahedral layers are connected to each other by VO4 tetrahedra. Pseudolyonsite is dimorphous with triclinic mcbirneyite. The name pseudolyonsite comes from its close visual similarity to another vanadate mineral, lyonsite, Cu3Fe3+4(VO4)6. Both the mineral and its name have been approved by the IMA CNMNC (IMA No. 2009-062).