Published electron microprobe analyses of mattheddleite, a lead sulpho-silicate apatite from Leadhills, Scotland, have 9–13% IV site deficiencies. However, galena was used as a standard for S, which suggested that low S resulted from a shift in the S-Kα peak. Wavelength scans with a PET crystal show that the S-Kα peak is shifted down by 0.0026 Å for sulphates relative to sulphides. Quantitative analyses show a ∼30% increase of S in mattheddleite using a celestite standard, which fills the IV site, but with Si > S, on average Pb5S1.2Si1.8O11.7Cl0.6(OH)0.4. Direct analysis of oxygen with the electron microprobe implies that the charge imbalance engendered from the inequality of Si and S is compensated with substitution of a vacancy (□), as in Pb5S1.2Si1.8[O11.7□0.3] [Cl0.6(OH)0.4] or Pb5S1.2Si1.8[O11.7(Cl, OH)0.73]. [Cl,OH)0.7 □0.3]. Calculation of OH as l–C1 suggests the presence of both OH- and Cl-dominant mattheddleite at Leadhills, but direct analysis of H is needed to confirm the dominance of OH in the channel site. Wavelength-dispersive analyses of S in apatite and other sulphates must be undertaken with sulphate standards: use of sulphide standards yields a negative error on the order of 10–20% in the resultant S concentration. Reactions of mattheddleite with other Pb minerals at Leadhills show that their stability depends on fluid composition as well as pressure and temperature. An X-ray map of Cl shows complex zoning between Cl-poor and Cl-rich mattheddleite, recording rapid changes in the fluid chemistry during late-stage hydrothermal processes at Leadhills.

Munakataite, Pb2Cu2(Se4+O3)(SO4)(OH)4, has been found in association with a variety of rare secondary Te minerals at Otto Mountain, San Bernardino County, California, USA. It is very rare and occurs as subparallel bundles of blue needles up to 1 mm long. Electron microprobe analyses provided the empirical formula Pb1.96Cu1.60[(Se0.894+S0.11)∑1O3](SO4)[(OH)3.34(H2O)0.66]∑4- Munakataite is mono-clinic, space group P21/m, with cell parameters a = 9.8023(26), b = 5.6751(14), c = 9.2811(25) Å, β = 102.443(6), V = 504.2(2) Å3 and Z = 2. The crystal structure, solved by direct methods and refined to R1 = 0.0308 for 544 Fo > 4σF reflections, consists of Jahn-Teller-distorted Cu2+O6 square bipyramids. which form chains along b by sharing trans edges across their square planes. The chains are decorated by SO4 tetrahedra and Se4+O3 pyramids, which bond to apical corners of adjacent bipyramids. The chains are linked to one another via bonds to two different PbO9 polyhedra, only one of which exhibits one-sided coordination typical of Pb2+ with a stereochemically active 6s2 lone-electron-pair. Munakataite is isostructural with schmiederite and the structure is closely related to that of linarite.

The Mathiatis massive sulphide deposit in Cyprus was a low-grade (0.3% Cu), three million ton ore body of pyrite and minor chalcopyrite occurring within basaltic lavas of the Troodos ophiolite. Cessation of mining in 1987 left a deep open pit surrounded by large heaps of spoil, which are undergoing oxidation and leaching. The aim of this study was to determine the mineralogical controls on the storage and potential remobilization of As, Cu, Pb and Zn within, and from, mine spoil heaps. Most of the spoil samples collected, and related materials (stream sediment, reaction zone between a boulder of massive pyrite and calcareous chert, salt crusts on stream beds), are enriched in As (27—220 ppm), Cu (110—400 ppm), Pb (10—140 ppm) and Zn (290—12,000 ppm) relative to both the basalt and calcareous chert (As 4—10 ppm, Cu 20—76 ppm, Pb 3—6 ppm, Zn 39—200 ppm).

Arsenic, Cu, Pb and Zn in the spoil and related materials are associated with Fe(-Al-S)-O, Fe(-Al-Mg)-S-O, Al(-Mg-Fe)-S-O and Mg(-Al-Fe)-S-O phases (the brackets represent minor components of less than 20 wt.% within the phases). Chemical extraction work using CaCl2 suggests that Cu, Zn and to some extent, As, are potentially more soluble than Pb. This is corroborated by the very high total concentrations of Cu and Zn in both the secondary salt crusts and the reaction zone material, high CaCl2-extractable As, Cu and Zn in the salt crusts, and aqueous data for the Mathiatis mine area collected for a European Union LIFE report. This may have implications for ecosystem health and water quality in the Mathiatis area and areas of similar mineralogy and climate world wide.

The type specimen of peisleyite has been reinvestigated by a combination of scanning electron microscopy, electron probe microanalysis (EPMA) and synchrotron powder X-ray diffraction. Morphological investigation showed that mats of peisleyite crystals, individually <3 μm across, are intergrown with wavellite veinlets to form the white cryptocrystalline material that is typical of ‘peisleyite’. New EPMA data (mean of 12 analyses) gave the empirical formula of peisleyite as (Na1.69Ca0.18)Σ1.87(Al9.04Fe0.03)Σ9.07[(P6.28S1.38Si0.25)O4]Σ7.91(OH)6.66·27.73H2O, or ideally Na2Al9[(P,S)O4]8(OH)6·28H2O. The associated wavellite was found to be F-rich. Synchrotron powder data were indexed and refined and gave the following unit cell: P1̄, a = 9.280(19), b = 11.976(19), c = 13.250(18) Å, α = 91.3(1), β = 75.6(1), γ = 67.67(1)°, V = 1308(5) Å3 and Z = 4. These data are significantly different to those reported in the original description of peisleyite.

Calcite growth rates were measured in the presence of sulphate using mixed-flow reactors and in situ Atomic Force Microscopy. Preliminary observations reveal that the kinetics and mechanism of the calcite growth was altered by the presence of sulphate. Calcite growth rates in the presence of sulphate (≥ mM) were decreased and two-dimensional nuclei tend to grow on top of existing nuclei, rather than spreading. The height of new nuclei was ~4 Å, 1 Å greater than that of pure calcite growth. This difference reflects the incorporation of tetrahedral SO2-4 anions into the calcite lattice.

Edwardsite, Cu3Cd2(SO4)2(OH)6·4H2O, is a new mineral from the Block 14 Opencut, Broken Hill, New South Wales, Australia. It occurs as druses of tabular and bladed crystals up to 0.06 mm in size, associated with niedermayrite and christelite. Edwardsite is pale blue, transparent with vitreous lustre and has excellent cleavage parallel to {100}. Density was not measured but the calculated density, from the empirical formula, is 3.53 g cm–3 and the Mohs hardness is ∼3. Optically, it is biaxial negative with α ∼ 1.74, β = 1.762(4), γ ∼ 1.77 and 2Vcalc. ∼ +62°. The optical orientation is X = b, Y ∼ a, Z ∼ c. Electron microprobe analysis gave (wt.%): CdO 32.43, CuO 28.06, ZnO 2.26, FeO 0.08, SO3 20.35, H2Ocalc. (from crystal-structure analysis) 14.14, totalling 99.32. The empirical formula, calculated on the basis of 18 oxygen atoms is Cu2.77Cd1.98Zn0.22Fe0.01(SO4)2.00(OH)5.95·4.06H2O. Edwardsite is monoclinic, space group P21/c, with a = 10.863(2) Å, b = 13.129(3) Å, c = 11.169(2) Å, β = 113.04(3)°, V = 1465.9(5) Å3 (single-crystal data) and Z = 4. The eight strongest lines in the powder diffraction pattern are [d (Å), (I/I0), (hkl)]: 9.991, (90), (100); 5.001, (90), (200, 21); 4.591, (45), (20); 3.332, (60), (300, 032); 3.005, (30), (03); 2.824, (40), (2); 2.769, (55), (20, 042, 10); 2.670, (45), (2). The crystal structure was determined by direct methods and refined to R1 = 3.21% using 1904 observed reflections with Fo > 4σ(Fo) collected using synchrotron X-ray radiation (λ = 0.773418 Å). The structure is based on infinite sheets of edge-sharing Cuϕ6 (ϕ: O2–, OH) octahedra and Cdϕ7 (ϕ: O2–, H2O) polyhedra parallel to (100). The sheets are decorated on both sides by corner-sharing (SO4) tetrahedra, which also corner-link to isolated Cdϕ6 octahedra, thus connecting adjacent sheets. Moderate-strong to weak hydrogen bonding provides additional linkage between sheets.

Tamarugite (NaAl(SO4)2.6H2O) occurs at Compton Chine (NGR SZ 36808513), on the Isle of Wight, U.K., as globular encrustations covering an area of 2.8 m2 on argillaceous pyritous siltstones of the Lower Greensand Group, Lower Cretaceous. It is proposed that the production of H2SO4 from oxidizing pyrite in the siltstones releases Al ions from the argillaceous sediments, the Na content being acquired from sea spray. An analogy is made between Compton Chine and an occurrence in Victoria, Australia.

The crystal structure of macphersonite (Pb4SO4(CO3)2(OH)2, Pcab, a = 9.242(2), b = 23.050(5), c = 10.383(2) Å) from Leadhills, Scotland has been determined to an R = 0.053. The structure has many features in common with its polymorph leadhillite including three distinct types of layers. Layer A includes sulphate tetrahedra, Layer B is composed of Pb and OH, while Layer C is composed of Pb and CO3 with topology identical to that in cerussite. In both macphersonite and leadhillite these layers are stacked along [010] as …BABCCBABCC… The double CC layer is almost identical in the two structures and forms a structural backbone and occurs in other structures including hydrocerussite and plumbonacrite. The sulphate layer shows the greatest difference between the two structures and can be described by a pattern of up or down pointing tetrahedra. For macphersonite the sequence along [001] is …UDUDUD… while in leadhillite the sequence along [010] is …UDDUUDDU… This latter sequence effectively doubles b relative to the equivalent direction in macphersonite. Susannite, a third polymorph, may have yet another sequence of sulphates to give trigonal symmetry; by heating leadhillite, displacive movements of sulphate groups may occur with a conversion to susannite.

Sedimentary and magmatic rocks and their distinct sulphur isotopic signatures indicate the sources and processes of sulphur cycling, in particular through the analysis of all four stable sulphur isotopes (32S, 33S, 34S and 36S). Research over the past 15 years has substantially advanced our understanding of sulphur cycling on the early Earth, most notably through the discovery of mass-independently fractionated sulphur isotopic signatures. A strong atmospheric influence on the early Archean global sulphur cycle is apparent, much in contrast to the modern world. Diverse microbially driven sulphur cycling is clearly discernible, but its importance for Earth surface environments remains to be quantified.

Various Mars missions have detected Cl atoms, chlorides and perchlorates in martian surface materials. The global soils, in particular, always contain significant levels of observable Cl. Direct evidence points to this Cl being in the form of both chlorides and perchlorates, and possibly also chlorates and other oxychlorines. The most widespread measurements have been of Cl atoms, and cannot discern the chemical form. However, from separate evidence of perchlorate obtained at high latitudes (Phoenix lander) and low latitudes (Curiosity rover), it is likely that perchlorates are widespread, albeit in varying proportions relative to the total amount of ubiquitous Cl.

Water-soluble sulphate minerals such as epsomite and gypsum have been reported on a number of planetary bodies of astrobiological interest and their presence is often used as an indicator for potential habitability as it can indicate the presence of liquid water. The sulphate minerals can incorporate biomarkers and biomolecules as intracrystalline inclusions. These intracrystalline inclusions are protected from their exterior chemical environments and their analysis can yield a biomarker record, even in environments where extreme oxidizing conditions may have degraded any record present in non-intracrystalline organic matter. In this study, organic compounds were incorporated within epsomite as intracrystalline inclusions by co-precipitating a mineral from solutions of a mineral and organic compound. A feasibly study utilizing a microfluidic H-cell to process finely ground samples of the inclusion-bearing epsomite indicates that a similar device may be used to extract biomarkers for analysis.

Two shallow ponds at Cape Evans, Ross Island, were sampled at 1–2 week intervals, during winter freezing throughout the winter and during the subsequent melt period, to examine the physical and chemical conditions imposed on the biota during the year. Liquid water was first detected at the base of the ponds in late December. During the main summer melt period conductivities were less than 10 mS cm−1 with maximum daily temperatures around 5°C. The bottom waters became increasingly saline during freezing and water temperatures decreased below 0°C; by June the remaining water overlying the sediments had conductivities >150 mS cm−1 and temperatures of −13°C. Calcium carbonate, then sodium sulphate precipitated out of solution during early freezing. The dominant nitrogen species was dissolved organic-N which reached 12 g m−3 in Pond 1 just prior to final freeze up. The organic and inorganic forms of nitrogen and dissolved reactive phosphorus increased with increasing conductivity in the ponds. The behaviour of particulate-N and particulate-P mirrored that of chlorophyll a with a peak in March-April and a second higher peak just before final freeze-up. This study provides clear evidence that organisms which persist throughout the year in Antarctic coastal ponds must be capable of surviving much more severe osmotic, pH, temperature and redox conditions than those measured during the summer melt. Deoxygenation, pH decline and H2S production, however, point to continued respiratory activity well into the dark winter months.

Four pot experiments are reported in which Norway spruce (Picea abies (L.) Karst) seedlings, of different nutrient status, were treated with acid mist for one growing season in open-top chambers (OTCs). Combinations of H+, SO42−, NH4+ and NO3− were applied at different frequencies of application and supplying different doses of S and N kg ha−1. Plant growth, visible injury, frost hardiness and nutrient status were observed. These experiments were undertaken to improve our understanding of the interaction of environmental factors such as nutrition and mist-exposure frequency on seedling response to N and S deposition.

Both acidity ([les ]pH 2·7) and SO42− ions were necessary to induce visible injury. Mist containing SO42−, H+ and to a lesser extent NH4+ significantly reduced winter frost hardiness. Increasing the misting frequency, and to a lesser extent the overall dose, increased the likelihood of acid mist causing visible injury and reducing frost hardiness. Post-planting stress, low N status and needle juvenility increased the likelihood of acid mist causing visible injury. Increased plant vitality, adequate N status and growth rate reduced the likelihood of acid-mist-induced reductions in frost hardiness.

Principles underlying the responses of spruce seedlings treated in controlled conditions to acid mist are discussed.

The incorporation of [35S]sulphur in thiophenes by Tagetes patula roots was used as a model to study the regulation of secondary metabolism with a limited supply of substrate. Growth and thiophene accumulation were measured in root cultures incubated at various sulphate concentrations in the medium. A 20-fold to 40-fold reduction in the sulphate concentration did not affect elongation growth, branching and biomass production within 14 d but decreased the thiophene level to 25–50% of the control in the same period. The reduction in thiophene content was found to result from a decline in biosynthetic capacity of 80–95% after 8 d. This capacity was restored when roots were transferred to standard medium. The restoration took more than 24 h and was suppressed by cordycepin, an inhibitor of mRNA processing. It is concluded that the rate of thiophene synthesis is regulated by a control mechanism that reacts to the availability of sulphate to the roots.