Au-Cu mineralization at Palai-Islica occurs as disseminations in massive silicified volcanic rocks and, more abundantly, in sulphide-bearing quartz veins. The major ore minerals in the deposit are pyrite ± chalcopyrite, sphalerite and galena and there is a great variety of accessory minerals, including Au-Ag alloys and native gold. Pyrite, the most abundant sulphide, is closely associated with gold. Seven different types of pyrite have been distinguished with a variable concentration of different trace elements. Among these, the only one free of trace elements (type IV) is related to Au-Ag alloys. Pyrite associated with these Au-Ag alloys has cubic and pentagonal dodecahedral habits, whereas pyrite with pentagonal dodecahedral habit only is from barren zones. In addition, there is no significant invisible gold in the pyrite, but there is a relatively large amount of Ag in collomorphic pyrite (up to 0.20 wt.%) or type III pyrite (up to 1.47 wt.%). Arsenic is the most abundant trace element in pyrite (up to 6.11 wt.%), present as a metastable solid solution or as a non-stoichiometric element. A variety of marcasite related to the gold levels also has a considerable amount of trace elements (As up to 1.15 wt.%, Sb up to 0.40 wt.%).

In bioreactor systems for the treatment of metal-contaminated water, pretreatment with zerovalent Fe can be exploited for oxygen consumption and H2 production. In this study, a column experiment is used to investigate the changes in surface chemistry and solid phase products that result from the reaction of a Zn-sulphate-lactate solution with zerovalent Fe filings. The results of this study indicate that zerovalent Fe is very effective in immobilizing dissolved Zn with a porewater residence time of 1.3 –3.1 days. A combination of X-ray diffractometry, X-ray photoelectron spectroscopy, and mineral equilibria calculations indicates that Zn precipitates as Zn(OH)2 and zincite at pH 9 –10. At pH ≈6, Zn primarily adsorbs to abundant ferric oxyhydroxides, although incorporation in green rust is also considered. During the course of the experiment, the surface mineralogy changes from magnetitelepidocrocite- goethite to green rust-akaganéite-goethite. The results suggest that the zerovalent Fe surface becomes passivated by a surface film of ferric oxyhydroxides, green rust and organic material, so that the rate of electron transfer and proton consuming reactions (i.e. oxygen consumption, H2 generation) declines, resulting in a decrease in solution pH.

The dispersion and sediment-water partitioning of Pb and Zn have been studied in the Conwy River, North Wales. Analysis included major and trace element water chemistry and concentrations of sediment-hosted Pb and Zn. In situ solution pH, Eh, temperature and conductivity were also measured. Sediments were characterized via SEM, XRD, nitric acid leaching and sequential chemical extraction to quantify metal distribution and sediment phase associations. Dissolved and sediment-bound Pb and Zn within river and estuary waters and sediments have been used to calculate whole sediment- and phase-specific apparent partition coefficients.

Weathering of galena and sphalerite, associated with the Llanrwst Mining Field, provide point sources of elevated dissolved and sedimentary Pb and Zn in the upper catchment. Dissolved Pb is actively adsorbed onto sedimentary surface coatings of Fe-Mn (hydr)oxides and organics whilst Fe-Mn (hydr)oxides, organics and carbonates were the main hosts for Zn. Systematic changes in metal sorption are evident between the estuary and the upper catchment, with organic matter becoming progressively more important upstream. This change is ascribed to the sorptive properties of sedimentary organic material. Solution pH, [Cl] and aqueous metal speciation are the dominant solution controls on metal partitioning. Laboratory sorption experiments parallel Pb sorption behaviour in the natural system.

Fluoronyböite, ideally NaNa2(Al2Mg3)(Si7Al)O22F2, has been found in the Jianchang eclogite pod, Su-Lu coesite-eclogite province, China. It has been approved as a new mineral by the IMA. Single-crystal structure refinement and electron microprobe analysis were used for characterization: C2/m, with a = 9.666(4), b = 17.799(6), c = 5.311(2) Å, β = 104.10(3)º, V = 886.2(8) Å3, Z = 2, formula: A(Na0.78K0.06)Σ0.84B(Na1.53Ca0.47)Σ2.00C(Fe2+0.89Mg2.55Mn0.01Zn0.01Fe3+0.32Al1.21Ti0.01)Σ5.00T(Si7.14Al0.86)Σ8.00O22X(OH0.84F1.16)Σ2.00.

Fluoronyböite formed during UHPM conditions, and is preserved in the retrograded kyanite-bearing eclogite sample DJ102 together with clinopyroxene (Jd70Ae20Di10), garnet (Alm60Prp21Grs17Sps02), and rutile. Lower-pressure minerals are also present (fluoro-alumino-magnesiotaramite, apatite, paragonite), and symplectitic rims were also developed around clinopyroxene crystals. Cation ordering and the structural and physical properties of fluoronyböite are reported and discussed with reference to those of F-free nyböite from the type locality at Nyböin Norway, for which some as yet unpublished mineral data are also reported. Relations between composition and petrogenetic conditions of these rare high-pressure amphiboles are discussed.

Fluorine-rich prismatine, (□,Fe,Mg)(Mg,Al,Fe)5Al4(Si,B,Al)5O21(OH,F), with F/(OH+F) = 0.36–0.40 and hercynite are major constituents of a Fe-Al-B-rich lens in ultrahigh-temperature granulite-facies quartz-sillimanite-hypersthene-cordierite gneisses of the Eastern Ghats belt, Andhra Pradesh, India. Hemo-ilmenite, sapphirine, magnetite, biotite and sillimanite are subordinate. Lithium, Be and B are concentrated in prismatine (140 ppm Li, 170 ppm Be, and 2.8 –3.0 wt.% B2O3). Another Fe-rich lens is dominantly magnetite, which encloses fine-grained zincian ferrohögbomite-2N2S, (Fe2+,Mg,Zn,Al)6 (Al,Fe3+,Ti)16O30(OH)2, containing minor Ga2O3 (0.30 –0.92 wt.%). Fe-Al-B-rich lenses with prismatine (or kornerupine) constitute a distinctive type of B-enrichment in granulite-facies rocks and have been reported from four other localities worldwide. A scenario involving a tourmalineenriched lateritic precursor affected by dehydration melting is our preferred explanation for the origin of the Fe-Al-B-rich lenses at the five localities. Whole-rock analyses and field relationships at another of these localities, Bok se Puts, Namaqualand, South Africa, are consistent with this scenario. Under granulite-facies conditions, tourmaline would have broken down to give kornerupine-prismatine (±other borosilicates) plus a sodic melt containing H2O and B. Removal of this melt depleted the rock in Na and B, but the formation of ferromagnesian borosilicate phases in the restite prevented total loss of B.

The development of protocols for the identification of metal phosphates in phosphate-treated, metalcontaminated soils is a necessary yet problematical step in the validation of remediation schemes involving immobilization of metals as phosphate phases. The potential for Raman spectroscopy to be applied to the identification of these phosphates in soils has yet to be fully explored. With this in mind, a range of synthetic mixed-metal hydroxylapatites has been characterized and added to soils at known concentrations for analysis using both bulk X-ray powder diffraction (XRD) and Raman spectroscopy.

Mixed-metal hydroxylapatites in the binary series Ca –Cd, Ca –Pb, Ca –Sr and Cd –Pb synthesized in the presence of acetate and carbonate ions, were characterized using a range of analytical techniques including XRD, analytical scanning electron microscopy (SEM), infrared spectroscopy (IR), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and Raman spectroscopy. Only the Ca –Cd series displays complete solid solution, although under the synthesis conditions of this study the Cd5(PO4)3OH end member could not be synthesized as a pure phase. Within the Ca –Cd series the cell parameters, IR active modes and Raman active bands vary linearly as a function of Cd content. X-ray diffraction and extended X-ray absorption fine structure spectroscopy (EXAFS) suggest that the Cd is distributed across both the Ca(1) and Ca(2) sites, even at low Cd concentrations.

In order to explore the likely detection limits for mixed-metal phosphates in soils for XRD and Raman spectroscopy, soils doped with mixed-metal hydroxylapatites at concentrations of 5, 1 and 0.5 wt.% were then studied. X-ray diffraction could not confirm unambiguously the presence or identity of mixed-metal phosphates in soils at concentrations below 5 wt.%. Raman spectroscopy proved a far more sensitive method for the identification of mixed-metal hydroxylapatites in soils, which could positively identify the presence of such phases in soils at all the dopant concentrations used in this study. Moreover, Raman spectroscopy could also provide an accurate assessment of the degree of chemical substitution in the hydroxylapatites even when present in soils at concentrations as low as 0.1%.

Arhbarite was described in 1982 as a new copper arsenate, Cu2(OH)AsO4·6H2O, from the Arhbar mine, Morocco. Due to the very small grain size no crystallographic data other than the X-ray powder diffraction data could be given. Reinvestigation of the type material and of new finds from the El Guanaco mine, Chile, is based on Rietveld refinement of X-ray powder data, electron microprobe investigations, optical studies as well as infrared and Raman spectra. The main results are: (1) arhbarite has the ideal formula Cu2Mg(AsO4)(OH)3 with magnesium oxide as an additional constituent and (2) arhbarite is isotypic with gilmarite, Cu3(AsO4)(OH)3. Arhbarite is triclinic, space group P1 (no. 1), unit-cell parameters (type material; refined from powder data) a= 5.315(4), b= 5.978(6), c= 5.030(6)Å, α = 113.58(6), β = 97.14(7), γ = 89.30(8)°, V= 145.2(1)Å3, Z= 1. Microprobe analyses of the type material gave MgO 10.20, CuO 47.46, NiO 0.20, CoO 0.24, As2O5 33.85, SiO2 0.10, H2O 7.58 (calc.), total 99.63 wt.%. The empirical formula is Cu1.98(Mg0.88Cu0.09Ni0.01Co0.01)S0.99(AsO4)1.02(OH)2.92, based on 7 O atoms. The Chilean arhbarite shows a slightly higher Cu content than the type material; it has the formula Cu1.99(Mg0.73Cu0.25Zn0.01)∑0.99[(AsO4)1.01(SiO4)0.01]∑1.02(OH)2.92. The formal redefinition of arhbarite has been approved by the CNMMN of the IMA.

Tidal mudflats are locally enriched in heavy metals at the head of Strangford Lough in Northern Ireland, where drainage from the hinterland enters the sea lough via a tidal canal in an urban area. To characterize the metallic contaminants and investigate their provenance, heavy particles separated from stream, canal and estuarine sediments were analysed by electron microprobe and laser Raman microspectroscopic methods. Potential metal sources are mineralization in the catchment area and industrial or domestic pollution. Anthropogenic particles include metallic grains, alloys and compounds of Pb, Zn, Cu, Fe, Cr and Sn. Alteration of metallic particles includes de-zincification of brass in freshwater sediment and replacement of Cu wire by covellite in brackish to marine sediment. Mobility of Cu, Fe and S in canal and estuarine sediments is indicated by the authigenic growth of framboidal Fe sulphide on oxide substrates and of chalcopyrite rims on covellite. Intricate colloform and platy crystalline textures suggest a cyclical deposition of covellite and chalcopyrite under conditions of varying redox and salinity. Lead and Cr mobility in the contaminated estuarine sediment is shown by the authigenic formation on Pb-rich substrates of heterogeneous Pb- and Cr-rich sulphate-phosphate compounds and Pb-oxychlorides.

The original description of nickelphosphide from the Butler meteorite [(Ni1.83Fe1.21)Σ3.04P0.96 to (Ni1.71Fe1.28Co0.01)Σ3.00P1.00] lacks detailed and accurate powder data – with only 11 observed reflections down to 1.37 Å. Consequently, no crystal structure information for this phase is available. Here we present the crystal structure for a synthetic analogue of the phase found in the Vicenice IID medium octahedrite (with a mean empirical formula of (Ni1.69Fe1.31)Σ3.00P1.00) and a hypothetical Ni3P end-member. Unit-cell dimensions of the synthetic analogue of Ni1.68Fe1.33P0.99 composition from individual peak profile fitting of XRD data collected with Cu radiation are a= 9.0168(2)Å, c= 4.4491(1)Å, V= 361.72(1)Å3 and those for Ni3P composition are a= 8.9546(1)Å, c= 4.38714(8)Å, V= 351.783(8)Å3. The space group of the mineral is I4¯ and Z= 8. The crystal structure refined from powder data by the Rietveld method is consistent with that refined and published for Fe3P and Ni3P synthetic compounds as well as Fe-dominant schreibersite from single-crystal data. However, because of the similarity of the scattering of iron and nickel, we were not able to refine directly the site occupancies in the synthetic analogue of the nickelphosphide from the Vicenice iron meteorite.

Stream sediment geochemistry provides an innovative method of assessing the basinal history of the Caledonian slate belts. Despite glaciation, the stream sediment geochemical patterns spatially mimic the outcrop of underlying bedrock lithologies. However, erosion from rock to sediment by fluvial processes may either increase or reduce an element’s abundance depending on the nature of its mineral host. An element held in heavy, resistate minerals will be concentrated, whereas one residing in unstable ferromagnesian minerals, which readily break down to clays during weathering, may be preferentially removed. Examples are provided from the Cr-Ni-V-Mg, base metal and Rb-Sr element suites. Primary and secondary bedrock patterns are recognized in the stream sediments. Primary patterns follow the original composition of the source bedrock, with steep gradients in the element distribution coinciding with lithostratigraphical boundaries. Such patterns also reveal subtle divisions within the established geological units for which the main compositional control was the nature of the ancient sedimentary provenance. Secondary patterns reflect remobilization of elements within the bedrock and so may cut across lithostratigraphical boundaries. These patterns (or their absence) are influenced by the thermal histories of the Caledonian basins, and so are indicative of the geotectonic regime in which the sedimentary sequences were originally deposited.

Small deviations from higher symmetry can be established by single-crystal diffraction methods by (1) measuring the metric of the unit cell with high, non-routine precision; (2) measuring a full reflection sphere of diffraction data and testing it for the presence or absence of symmetry elements in the dataset; (3) refining the structure in both the higher and the lower symmetry and comparing the results; (4) checking the refined crystal structures for the presence or absence of hidden symmetry elements. By these criteria it is not established that the v{120} growth sector of yugawaralite really has triclinic symmetry (Tanaka et al., 2002). On the contrary, the refined metrical parameters and the atomic positions conform to monoclinic symmetry within the margins of experimental error.

The crystal structure of hügelite, Pb2[(UO2)3O2(AsO4)2](H2O)5, monoclinic, space group P21/m, a= 31.066(3)Å, b= 17.303(2)Å, c= 7.043(1)Å, β = 96.492(2)°, V= 3761.6(1)Å3, Z= 8, Dcalc = 5.74 g/cm3, was solved by direct methods using data from a crystal twinned by pseudo-merohedry, and was refined by full-matrix least-squares techniques on the basis of F2 to agreement indices R1 of 3.3% calculated for 5519 unique observed reflections (|Fo| 5 ≥ 4σF), and wR2 of 6.7% for all data. Intensity data were collected at room temperature using Mo-Kα radiation and a CCD-based area detector. Hügelite is a member of the phosphuranylite group and is the arsenate counterpart of dumontite. The sheets of uranyl pentagonal and hexagonal bipyramids and arsenate tetrahedra in hügelite are oriented parallel to (100), and the interlayer contains four symmetrically independent Pb atoms, each of which is coordinated by two oxygen atoms from uranyl ions, two oxygen atoms from arsenate tetrahedra, and three symmetrically distinct H2O groups. The unit-cell volume is four times larger than that previously reported for hügelite, or expected by comparison to dumontite, Pb2[(UO2)3O2(PO4)2](H2O)5; the larger cell probably results from the accommodation of the larger As atoms (relative to P) in the structure, and consequent subtle variations in the coordination geometries of the U and Pb positions.

The profile of the supergene zone of the Zapadno-Ozernoe massive sulphide Cu-Zn deposit differs from the classic model (Emmons, 1917) in that it includes a prominent dark sooty subzone rich in secondary sulphides. This subzone is situated above residual pyrite sands, which overlie the massive sulphide body and below quartz-baryte leached sands. It contains a diverse mineral assemblage which consists of secondary sulphides such as galena, sphalerite, metacinnabar, Se-bearing pyrite—dhzarkenite series, tiemannite, native Au, native S and native Se, and unidentified sulphosalts of Ag and Hg. The very light S isotope composition of the secondary sulphides (lowest values δ34S = —17.2‰ (VCDt) in comparison with primary pyrite ∼0‰ and baryte +18.4‰ is indicative of bacterial sulphate reduction. The overlying oxidized part of the supergene column contains minerals of the jarosite-beudantite- segnitite series. The maximum concentrations of Au, up to 150 ppm, occur in the lower part of the profile. The atypical structure, mineral assemblage and S isotope composition of the secondary sulphides in the dark layer of the supergene profile are indicative of particular geochemical conditions due to the existence of a stagnant water body that gave rise to intense bacterial activity, in turn controlled by fluctuations in the redox boundary.

Dumortierite occurs as small nodules or thin layers along horizontal fractures in the altered volcanic rocks of the Milyang clay deposit, southeastern Korea. Textural evidence shows that dumortierite is associated with pyrophyllite, suggesting that the silica activity increased with decreasing B and Al activities during the hydrothermal alteration. Dumortierite chemistry shows a slight excess of Al, possibly due to common occurrence of Al-rich minerals in the clay deposit. The structural formula of dumortierite is recalculated as Al6.93(Fe0.03Mg0.07)B(Si2.99Al0.01)O18. An absorption peak at 1387 cm–1 in the IR spectrum indicates that B is present in three-fold coordinated sites. The 29Si MAS NMR spectrum has two peaks at –90.9 and –95.5 ppm, showing that Si in dumortierite is located in two different crystallographic sites and is linked to four octahedral Al atoms. The 27Al MAS NMR spectrum shows only one asymmetrical peak near 0 ppm, suggesting that there is no substitution of Al for Si. The 11B MAS NMR spectrum at 17.5 ppm shows a typical second order quadrupole pattern represented by the three-fold coordinated B. The 11B chemical shifts indicate that all of the B occupies such sites, indicating that the B sites are axially symmetric or nearly so in a very well defined site.

The chemical composition of unaltered biotites extracted from 18 Lower Palaeozoic metabentonites from Sweden, Norway and Scotland was determined. Discrimination based on FeO, MgO and TiO2 proved able to separate the metabentonites on the basis of their stratigraphical age. A triangular discrimination diagram using MgO, FeO and Al2O3 classified the biotites as calc-alkaline. Independent support for the discriminant power of FeO, MgO and TiO2 in biotite comes from Sr isotope ratios and Sr concentration data from cognate apatite crystals. Within this dataset Caradocian and Llandoverian metabentonites have unique biotite compositions, while Wenlockian samples can be characterized to a lesser degree. Biotite composition also supported the correlation of a pair of metabentonites from Norway known to form part of the same horizon. Biotite in metabentonites preserves the chemical signature of the host magmas in which it crystallized and can be used to discriminate between metabentonites of different ages and provenance.