The composition of topaz from different granites and greisen in the Krušné Hory/Erzgebirge area was investigated using electron microprobe analysis (EMPA) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). All topaz grains are rich in F (17.9 19.8 wt.%, 1.73 1.90 a.p.f.u.) and the most important minor/trace elements are P, Ge and Ga. Contents of P up to 1 wt.% P2O5 (0.025 a.p.f.u.) were found in topaz from the strongly peraluminous P-rich magmatic systems at Podlesí. Regardless of genetic type, topaz from granites typically contains 50 100 ppm Ge. The greatest amounts (up to 204 ppm Ge) were found in topaz from quartz-topaz-apatite greisen in Krásno. In fractionated granites and greisens, topaz is calculated to contain 23 87% of the bulk Ge content in the rock. In contrast, topaz does not concentrate Ga. The Ga content of topaz (typically 5 35 ppm in S-type granites, <10 ppm Ga in A-type granites) is usually smaller than the bulk Ga content of the rock. In addition, up to 16 ppm Sc, 23 ppm Sn and >400 ppm Fe may be present.

The crystal structure of a Te-rich polybasite has been refined by means of X-ray diffraction data collected at room temperature (space group Pm1; R = 0.0505 for 964 observed reflections and 94 parameters; refined formula Ag14.46Cu1.54Sb1.58As0.42S9.67Te1.33). The structure comprises stacking of [(Ag, Cu)6(Sb, As)2(S, Te)7]2–A and [Ag9Cu(S, Te)2(S, Te)2]2+B layer modules in which Sb forms isolated SbS3 pyramids, as occurs typically in sulfosalts, Cu links two S atoms in a linear coordination and Ag occupies sites with coordination ranging from quasi linear to almost tetrahedral. The silver d10 ions are found in the B layer module along two-dimensional diffusion paths and their electron densities evidenced by means of a combination of a Gram-Charlier development of the atomic displacement factors and a split model. The Te-for-S substitution occurs at the same structural sites that Se substitutes for S in selenopolybasite and the Te occupancy at one of these sites is 0.49, thus suggesting the possibility that 'telluropolybasite' could be found in nature.

Leydetite, monoclinic Fe(UO2)(SO4)2(H2O)11(IMA 2012–065), is a new supergene uranyl sulfate from Mas d'Alary, Lodève, Hérault, France. It forms yellow to greenish, tabular, transparent to translucent crystals up to 2 mm in size. Crystals have a vitreous lustre. Leydetite has a perfect cleavage on (001). The streak is yellowish white. Mohs hardness is ∼2. The mineral does not fluoresce under long- or short-wavelength UV radiation. Leydetite is colourless in transmitted light, non-pleochroic, biaxial, with α = 1.513(2), γ = 1.522(2) (further optical properties could not be measured). The measured chemical composition of leydetite, FeO 9.28, MgO 0.37, Al2O30.26, CuO 0.14, UO340.19, SO321.91, SiO20.18, H2O 27.67, total 100 wt.%, leads to the empirical formula (based on 21 O a.p.f.u.), (Fe0.93Mg0.07Al0.04Cu0.01)Σ1.05(U1.01O2)(S1.96Si0.02)Σ1.98O8(H2O)11. Leydetite is monoclinic, space group C2/c, with a = 11.3203(3), b = 7.7293(2), c = 21.8145(8) Å, β = 102.402(3)°, V = 1864.18(10) Å3, Z = 4, and Dcalc = 2.55 g cm–3. The six strongest reflections in the X-ray powder diffraction pattern are [dobs in Å (I) (hkl)]: 10.625 (100) (002), 6.277 (1) (11), 5.321 (66) (004), 3.549 (5) (006), 2.663 (4) (008), 2.131 (2) (0 0 10). The crystal structure has been refined from single-crystal X-ray diffraction data to R1 = 0.0224 for 5211 observed reflections with [I > 3σ(I)]. Leydetite possesses a sheet structure based upon the protasite anion topology. The sheet consists of UO7 bipyramids, which share four of their equatorial vertices with SO4 tetrahedra. Each SO4 tetrahedron, in turn, shares two of its vertices with UO7 bipyramids. The remaining unshared equatorial vertex of the bipyramid is occupied by H2O, which extends hydrogen bonds within the sheet to one of a free vertex of the SO4 tetrahedron. Sheets are stacked perpendicular to the c direction. In the interlayer, Fe2+ ions and H2O groups link to the sheets on either side via a network of hydrogen bonds. Leydetite is isostructural with the synthetic compound Mg(UO2)(SO4)2(H2O)11. The name of the new mineral honours Jean Claude Leydet (born 1961), an amateur mineralogist from Brest (France), who discovered the new mineral.

The new mineral aluminopyracmonite, ideally (NH4)3Al(SO4)3, was found in a medium-temperature (∼250°C) intracrater active fumarole at La Fossa crater, Vulcano, Aeolian Islands, Sicily, Italy. It occurs on a pyroclastic breccia as colourless to white prismatic crystals up to 0.2 mm long, in association with adranosite, mascagnite, alunite and salammoniac. The mineral is identical to the synthetic compound (NH4)3Al(SO4)3. It is trigonal, space group: R (no. 148) with a = 15.0324(8), c = 8.8776(5) 5, V = 1737.3(2) Å3 and Z = 6. The six strongest reflections in the X-ray powder diffraction pattern are: [dobs in Å (I)(hkl)] 3.336(100)(131), 7.469(62)(1 1 0), 3.288(60)(122), 4.289(45)(31), 2.824(29)(51), 4.187(27) (012). The empirical formula based on 12 anions is [(NH4)2.89K0.10]Σ 2.99(Al1.18Fe0.01)Σ 1.19S2.91O12, and the simplified formula (NH4,K)3Al(SO4)3. The measured density is 2.12(1) g/cm3, calculated density 2.143 g/cm3. The mineral is uniaxial(–) with ω = 1.545(3) and ε = 1.532(3) (λ = 589 nm). Using single-crystal diffraction data, the structure was refined to a final R(F) = 0.0258 for 998 independent observed reflections [I > 2σ(I)]. In spite of having unitcell parameters comparable with those of pyracmonite, the two minerals are not isostructural; the difference is related to a disordered conformation of the sulfate anions about the two independent Al3+ ions in aluminopyracmonite.

Camaronesite (IMA 2012-094), [Fe3+(H2O)2(PO3OH)]2(SO4)·1–2H2O, is a new mineral from near the village of Cuya in the Camarones Valley, Arica Province, Chile. The mineral is a low-temperature, secondary mineral occurring in a sulfate assemblage with anhydrite, botryogen, chalcanthite, copiapite, halotrichite, hexahydrite, hydroniumjarosite, pyrite, römerite, rozenite and szomolnokite. Lavender-coloured crystals up to several mm across form dense intergrowths. More rarely crystals occur as drusy aggregates of tablets up to 0.5 mm in diameter and 0.02 mm thick. Tablets are flattened on {001} and exhibit the forms {001}, {104}, {015} and {018}. The mineral is transparent with white streak and vitreous lustre. The Mohs hardness is 2½, the tenacity is brittle and the fracture is irregular, conchoidal and stepped. Camaronesite has one perfect cleavage on {001}. The measured and calculated densities are 2.43(1) and 2.383 g/cm3, respectively. The mineral is optically uniaxial (+) with ω = 1.612(1) and ε = 1.621(1) (white light). The pleochroism is O (pale lavender) > E (colourless). Electron-microprobe analyses provided Fe2O331.84, P2O529.22, SO315.74, H2O 23.94 (based on O analyses), total 100.74 wt.%. The empirical formula (based on 2 P a.p.f.u.) is: Fe1.94(PO3OH)2(S0.96O4)(H2O)4·1.46H2O. The mineral is slowly soluble in concentrated HCl and extremely slowly soluble in concentrated H2SO4. Camaronesite is trigonal, R32, with cell parameters:a = 9.0833(5), c = 42.944(3) Å, V = 3068.5(3) Å3 and Z = 9. The eight strongest lines in the X-ray powder diffraction pattern are [dobs Å (I)(hkl)]: 7.74(45)(101), 7.415(100)(012), 4.545(72)(110), 4.426(26)(018), 3.862(32)(021,202,116), 3.298(93)(027,119), 3.179(25)(208) and 2.818(25)(1·1·12,125). In the structure of camaronesite (R1 = 2.28% for 1138 Fo > 4σF), three types of Fe octahedra are linked by corner sharing with (PO3OH) tetrahedra to form polyhedral layers perpendicular to c with composition [Fe3+(H2O)2(PO3OH)]. Two such layers are joined through SO4 tetrahedra (in two half-occupied orientations) to form thick slabs of composition [Fe3+(H2O)2(PO3OH)]2(SO4). Between the slabs are partially occupied H2O groups. The only linkages between the slabs are hydrogen bonds. The most distinctive component in the structure consists of two Fe octahedra linked to one another by three PO4 tetrahedra yielding an [Fe2(PO4)3] unit. This unit is also the key component in the sodium super-ionic conductor (NASICON) structure and has been referred to as the lantern unit. The polyhedral layers in the structure of camaronesite are similar to those in the structure of taranakite. The Raman spectrum exhibits peaks consistent with sulfate, phosphate, water and OH groups.

Fluorcalcioroméite, (Ca,Na)2Sb25+(O,OH)6F, is a new roméite-group, pyrochlore-supergroup mineral (IMA 2012-093), from Starlera mine, Ferrera, Hinterrhein district, Grischun, Switzerland. The intimately associated minerals are: braunite, hematite, calcite, quartz and, rarely, wallkilldellite-(Mn). It occurs as euhedral octahedra, untwinned, from 0.1 to 1 mm in size. The crystals are yellow to orange and translucent; the streak is white, and the lustre is vitreous to resinous. It is non-fluorescent under ultraviolet light. Mohs' hardness is ∼5½, tenacity is brittle. Cleavage is not observed; fracture is conchoidal. The calculated density is 5.113 g/cm3. The mineral is isotropic, ncalc. = 1.826. The Raman spectrum is dominated by bands of Sb–O octahedral bond stretching and O–Sb–O bending modes. The chemical composition (n = 13) is (by wavelength-dispersive spectroscopy (WDS), H2O calculated by difference, wt.%): Na2O 4.11, CaO 15.41, MnO 0.54, CuO 0.01, ZnO 0.01, PbO 0.02, Al2O3 0.10, FeO 0.50, Y2O3 0.07, SiO2 0.04, TiO2 0.01, UO2 0.01, Sb2O5 76.18, WO3 0.78, F 2.79, H2O 0.59, O = F–1.17, total 100.00. The empirical formula, based on 2 cations at the B site, is (Ca1.16Na0.56☐0.22Fe0.032+ Mn0.032+)Σ2.00(Sb5+1.98Al0.01W0.01)Σ2.00O6[F0.62(OH)0.28O0.06☐0.04]Σ1.00. The strongest eight X-ray powder-diffraction lines [d in Å (I)(hkl)] are: 5.934(81)(111), 3.102(20)(311), 2.969(100)(222), 2.572(6)(400), 1.979(7)(333), 1.818(8)(440), 1.551(15)(622), and 1.484(5)(444). The crystal structure refinement (R1 = 0.0106) gave the following data: cubic, Fdm, a = 10.2987(8) Å, V = 1092.31(15) Å3, Z = 8. Unit-cell parameters refined from the powder data are: a = 10.284(2), V = 1087.7(7) Å3, Z = 8.

Weissite, Cu2–xTe (x ≈ 0.21), a very rare copper telluride, occurs in a sample from the Gambatesa mine, Val Graveglia, Liguria, Italy, where it occurs as purplish black anhedral grains up to 0.1 mm in length and shows a black streak. No cleavage is observed and the Vickers hardness (VHN100) is 142 kg/mm2. Weissite is dark bluish black, weakly pleochroic, and moderately anisotropic in bluish tints. Reflectance percentages in air for Rmin and Rmax are 37.0, 38.4 (471.1 nm), 33.2, 34.2 (548.3 nm), 31.2, 32.1 (586.6 nm), and 28.6, 31.0 (652.3 nm), respectively.

Weissite is trigonal and belongs to the space group P3m1 with the following unit-cell parameters: a = 8.3124(7) Å, c = 21.546(1) Å, V = 1289.3(2) Å3, and Z = 24. Electron microprobe analyses gave the chemical formula (Cu1.62Ag0.04Au0.04Fe0.04Sb0.04)Σ=1.78(Te0.96S0.02Se0.02). The crystal structure has been solved and refined to R = 1.95%. It consists of Cu and Te polyhedra forming complex crystal-chemical environments as is typical of many intermetallic compounds. The exceedingly short bond distances observed among the metals are discussed in relation to other copper tellurides and pure metals.

The crystal chemistry of sekaninaite from Dolní Bory, Czech Republic, was characterized by a multimethod approach. Particular emphasis was put on the characterization of the channel constituents (i.e. H2O and CO2). Electron microprobe analysis shows the sample to be close to the Fe endmember [XFe = Fe/(Fe+Mg) = 94%) with significant Mn (1.48 wt.%) present; laser ablation mass-spectrometry showed the presence of 0.42 wt.% Li2O. H2O and CO2 contents (1.48 and 0.17 wt.%, respectively) were determined via secondary-ion mass-spectrometry. Sample homogeneity was checked by Fourier-transform infrared (FTIR) imaging using a microscope equipped with a focal plane array detector. Single-crystal FTIR spectroscopy confirmed the presence of two types of H2O groups in different orientations (with prevalence of the type II orientation), and that CO2 is oriented preferentially normal to the crystallographic c axis. Using the Beer-Lambert relation, integrated molar coefficients, εi, were calculated for both types of H2O (εi H2O[I] = 6000±2000; εi H2O[II] = 13000±1000) and for CO2 (εiCO2 = 2000±1000).

This paper relates an infrared (IR) (6000–2500; 1400–400 cm–1) spectroscopic study of sideronatrite, Na2Fe3+(SO4)2(OH)·3H2O. Spectra in the 600–1250 cm–1 range are dominated by fundamental S–O absorption bands. Factor-group analysis based on the space group P212121(D42) is in accordance with the observed band multiplicity. A broad and convolute absorption centred around 3400 cm–1 and a sharp band at 3605 cm–1 are observed in the 2900–3900 cm–1 frequency region. The resolution of the broad band is significantly improved at liquid nitrogen temperature; seven components can be fitted to the pattern and these can be assigned to H2O/OH molecules in the structure. All components in the broad band and the sharp absorption at 3605 cm–1 are strongly polarized for E//a, in accordance with the structure analysis results. Infrared transmission spectroscopy is a useful tool to identify these sulfate minerals occurring in specific geological environments.

Domerockite, Cu4(AsO4)2(AsO3OH)(OH)3·H2O, is a new mineral from the Dome Rock Mine, South Australia. It occurs as aggregates of bluish green, equant to short prismatic and tabular crystals up to 0.3 mm long and 0.2 mm across. Domerockite is translucent, with a vitreous lustre and pale green streak. It displays no fluorescence under UV irradiation. The mineral is brittle with an uneven fracture, a Mohs hardness of ∼3 and a calculated density of 4.44 g/cm3 (based on the structure refinement). Optically, it is biaxial negative, with α = 1.798(4), β = 1.814(4), γ = 1.817(4), 2Vcalc. = 46°; pleochroism is very weak; X pale greenish yellow, Y greenish blue, Z greenish blue; absorption X < Y = Z; orientation is uncertain. Chemical analysis by electron microprobe gave CuO 52.04, ZnO 0.78, BaO 0.11, As2O537.67, P2O50.32, SiO20.24, H2O 8.84, total 100.00 wt.%, with H2O calculated by difference. The empirical chemical formula is (Cu3.94, Zn0.06)Σ4.00H0.91(As1.97, P0.03, Si0.02)Σ2.02O8(OH)3.00˙H2O based on 12 oxygen atoms.

Domerockite is triclinic, space group P, with a = 5.378(11), b = 8.962(18) c = 9.841(2) Å, α = 75.25(3), β = 83.56(3), γ = 79.97(3)°, V = 450.5(16) Å3 and Z = 2. The eight strongest lines in the X-ray powder diffraction pattern are [d (Å), (I)(hkl)]: 4.716 (30)(101, 002, 111), 3.697 (25)(121), 3.605 (30)(120, 12), 3.119 (60)(12), 3.073 (100)(1), 2.856 (40)(02, 030), 2.464 (50)(212, 13), 2.443 (40)(014). The crystal structure of domerockite has been solved by direct methods and refined to an R index of 7.44% using 2635 observed reflections. The structure comprises [Cuφ4] (φ = O, OH) chains of edge-sharing sharing, distorted octahedra that extend along [10] and are decorated by AsO4 tetrahedra to form sheets in the (010) plane. Dimers of edge-sharing [CuO4(OH)(H2O)] octahedra share corners with dimers of edge-sharing [CuO4(OH)] square pyramids to form zigzag chains which extend along [101]. The chains lie between and link to the sheets by sharings corners of octahedra, square pyramids and tetrahedra to form a heteropolyhedral framework.

The Kûngnât Complex (1275±1.8 Ma) in the Gardar Alkaline Province, South Greenland, cuts Archaean gneisses and comprises two intersecting syenitic stocks and a gabbroic ring-dyke. The magmas, with increasingly more primitive compositions, were emplaced successively by ring-faulting and roof stoping. The syenites are orthocumulates (cumulus alkali feldspar, olivine, pyroxene, titanomagnetite and apatite; intercumulus phases include alkali amphibole, biotite, quartz and calcite). In the well dissected earlier stock, a 2.2 km-thick layered sequence displays graded modal layering, feldspar lamination and cryptic layering. Modal layering in both stocks is directed mainly inwards at 35° – 50°. Heterogeneous nucleation of the cumulus assemblage, close to steep thermal boundary layers, is inferred. The modal layering is ascribed primarily to gravitational sorting aided by the large density differential between a) feldspar and b) Fe-rich silicates and oxides. Episodic collapse of cumulus + melt slurries contributed to inward-dipping crystal pediments on the chamber floors. The Ring-Dyke (up to 100 m wide) is nearly continuous through 360°. Kûngnât exhibits a compositional nearcontinuum from olivine gabbro through syenite intermediaries to alkali granite, ascribed to protracted assimilation/fractional crystallization processes. The most radiogenic Nd isotope data from Kûngnât (εNdi values between –3.3 and –1.0) point to a lithospheric mantle source, whereas the most unradiogenic values imply enrichment in LREE by crustal contamination of the magmas.