The specimen of cordierite-gneiss under notice was collected by Mr. T. N. Muthuswami (Assistant Professor of Geology, Presidency College, Madras) in a quarry at Ganguvarpatti in the Madura district. On examining tliin sections of the rock, he found that many of the cordierite crystals were optically positive, and, thinking that the mineral might be worth further investigation, he sent a specimen of the rock to me. The investigation was carried out ill the Geological Department of the Imperial College of Science and Technology, and my thanks are due to Professor W. W. Watts and Dr. J. W. Evans for their kindness in affording me facilities for this work and also to Dr. H. H. Thomas, of H.M. Geological Survey, for his kindness in placing Fedorov's universal stage at my disposal for the measurement of the optic axial angle.

In the Geological Survey memoir a dike is recorded cutting the Lewisian gneiss near Achmelvich, north-west of Lochinver, Sutherland. At the time the mapping was carried out no thin section was prepared of the rock, and the dike was presumed to be a continuation of the Canisp porphyry dike which is exposed in the river Inver near Lochinver and farther south-east.

During an investigation of the post-Cambrian sills and dikes of Assynt and the adjoining districts of north-west Scotland, the writer examined the Achmelvich dike in some detail and recognized its affinities with the nepheline-syenites. It is the purpose of the present note to describe the field occurrence and petrography of the dike.

The albitisation of pelitic metasediments to form adinoles adjacent to minor mafic intrusions has in the past been attributed to Na-bearing metasomatizing fluids emanating from the intrusions themselves. The chemistry and mineralogy of adinoles associated with dykes forming a high-intensity swarm in the Tallaght area, County Dublin, Ireland, confirms a metasomatic origin for the adinoles described, with Na and to a lesser extent Ca introduced into the country rocks at the expense of K. We suggest, however, that the source of the metasomatizing fluids was external to the dykes — possibly involving a hydrothermal system driven by an underlying magma reservoir that was parental to the dykes and also contributed volatiles to the hydrothermal system by degassing. Heat flow from the dykes was instrumental in promoting the reaction between muscovite in the country rock pelites and the Na(Ca)-bearing fluids to form albite, temperatures of ∼350°C in the country rocks within a metre of the contact being indicated. The mechanism of adinolization proposed is shown to be compatible with recent experimental work on the hydrothermal alteration of greywackes and basalts and also with the likely temperature gradients adjacent to dykes.

Phosphatic limestones and a related soil were described from collections made by the first Royal Society coral-reef-boring expedition to Funafuti in 1896 (Cooksey, 1896; David and Sweet, 1904, Judd, 1904; Sollas, 1904; cf. Cullis, 1904). Although there is some geographic uncertainty about the source of some of Judd's samples, the specimens came from three localities on Funafuti, the largest being on Amatuku.

A new mineral species, guangyuanite, ideally Pb3Cl3(Se4+O3)(OH), was discovered from the El Dragón mine, Antonio Quijarro Province, Potosí Department, Bolivia. It occurs as equant crystals. Associated minerals are Co-bearing krut'aite–penroseite, chalcomenite, schmiederite, olsacherite, phosgenite, anglesite, cerussite and franksousaite. Guangyuanite is pale yellow–brown in transmitted light, transparent with white streak and vitreous lustre. It is brittle and has a Mohs hardness of ~3. No parting or cleavage was observed. The calculated density is 7.63 g/cm3. An electron microprobe analysis yielded an empirical formula [based on 7 (O + Cl) atoms per formula unit] of Pb3.02Cl3.01(Se4+0.99O3)(OH), which can be simplified to Pb3Cl3(Se4+O3)(OH).

Guangyuanite is isostructural with synthetic Pb3Br3(Se4+O3)(OH). It is orthorhombic, with space group Pnma and unit-cell parameters a = 11.0003(5), b = 10.6460(5), c = 7.7902 Å, V = 912.31(6) Å3 and Z = 4. The crystal structure of guangyuanite contains two symmetrically-distinct Pb (Pb1 and Pb2) cations, with Pb1 coordinated by eight anions (4O + 4Cl) and Pb2 only by six anions (3O + 3Cl), forming a marked lopsided coordination typical of Pb2+ with a stereochemically active 6s2 lone electron pair. The Se4+ cation forms a typical [Se4+O3] trigonal pyramid. The crystal structure of guangyuanite can be described as consisting of layers of edge-sharing [Pb1O4Cl4] polyhedra parallel to (100). These layers are linked together by sharing polyhedral corners (Cl atoms), as well as [Pb2O3Cl3] and [Se4+O3] groups. Chemically, guangyuanite is one of six lead chloride selenite minerals reported thus far and closely related to orlandiite Pb3Cl4(Se4+O3)⋅H2O.

Kurilite, with the simplified formula, Ag8Te3Se, is a new mineral from the Prasolovskoe epithermal Au-Ag deposit, Kunashir Island, Kuril arc, Russian Federation. It occurs as aggregates up to 2 mm in size, composed of brittle xenomorphic grains, up to several μm in size, in quartz, associated with tetrahedrite, hessite, sylvanite and petzite. Kurilite is opaque, grey, with a metallic lustre and a black streak. Under plane-polarized light, kurilite is white with no observed bireflectance, cleavage, or parting observed. Under crossed polars it appears isotropic without internal reflections. Reflectance values in air and in oil, are tabulated. It has a mean VHN (25 g load) of 99.9 kg/mm2 which equates roughly to a Mohs hardness of 3. Electron microprobe analyses yield a mean composition of Ag 63.71, Au 0.29, Te 29.48, Se 5.04, S 0.07, total 98.71 wt.%. The empirical formula (based on 12 atoms) is (Ag7.97Au0.02)Σ7.99Te3.00(Se0.86Te0.12S0.03)Σ1.01. The calculated density is 7.799 g/cm3 (based on the empirical formula and unit-cell parameters refined from single-crystal data). Kurilite is rhombohedral, R3 or , a 15.80(1), c 19.57(6) Å, V 4231(12)Å3, c:a 1.2386, Z = 15. Its crystal structure remains unsolved. The seven strongest lines of the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 3.727(20)(131), 2.996(50)(232), 2.510(30)(226,422), 2.201(100)(128,416,342), 2.152(20)(603), 2.079(30)(253), 2.046(20)(336,434). The mineral is named after the locality.

White and yellowish precipitates were found in a gravel pit in the Kumpuselkäesker chain during the summers of 2004—2007. The esker is located in northern Finland, in the northern Ostrobothnia schist area which contains mica schists with quartz veins, which are locally enriched in Co, Cu, Au, Zn, Pb and Ni. A thin till bed lies between the esker gravel and bedrock. Precipitates were found as small grains on the till surface, encrusting twigs and around small pebbles. Ground-water ponds in the pit measured in the summer of 2006 were very acidic as was the till material. The precipitates comprise secondary sulphates, such as gypsum, pickeringite and Mg-sulphates, which are all water-soluble.

Five povondraite crystals from San Francisco Mine, Villa Tunari, Bolivia, have been structurally and chemically characterised by single-crystal X-ray diffraction and electron microprobe analysis. For the first time, this characterisation is accompanied by Mössbauer spectroscopic and single-crystal infrared spectroscopic data, which show the exclusive presence of Fe3+ at both the octahedrally-coordinated Y and Z sites as well as slight disorder of (OH) and O over the O(1) and O(3) sites.

The data obtained along with those for earlier-studied bosiite and oxy-dravite oxy-tourmalines show a complete substitution series described by the reaction YFe3+3 + ZMg + ZFe3+4 ↔ YAl2 + YMg + ZAl5 (i.e. Fe3+Al–1) with variation of the structural parameters dominated by Fe3+ (or Al). Povondraite is the tourmaline member having the largest unit-cell parameters due to the larger size of Fe3+ relative to other trivalent cations (V > Cr > Al). In the tourmaline-supergroup minerals, the a and c unit-cell parameters vary from ~15.60 Å to ~16.25 Å and ~7.00 Å to ~7.50 Å, respectively. Their values increase with increasing Fe3+ or decreasing Al. End-member compositions related to the smallest and largest a and c parameters are, respectively, NaAl3Al6(Si3B3O18)(BO3)3(OH)3(OH) (synthetic tourmaline) and NaFe3+3(Fe3+4Mg2)(Si6O18)(BO3)3(OH)3O (povondraite).

In the UK, technetium may be disposed of in a high pH, low Eh cementitious repository. In such a scenario, its chemistry would be dominated by TcO4 −, in aerobic conditions and the sparingly soluble TcO2(s) in anaerobic conditions. Repository heterogeneity could mean that both Tc(VII) and Tc(IV) are present simultaneously. The anthropogenic ligands EDTA and picolinic acid are commonly used as decontamination agents and are likely to be present in intermediate-level waste (ILW). They could complex with Tc(IV) increasing its aqueous concentration and mobility in the cement porewaters and beyond. The conditional stability constants (measured in 0.3 mol dm−3 NaOH) for the Tc(IV)–EDTA and Tc(IV)–picolinic acid complexes have been determined to be: βTc(IV)−EDTA = 1.6 × 1026, which corresponds to log β = 25.2±0.6; and βTc(IV)−PA = 8.65 × 1026, which corresponds to log β = 26.9±0.1, respectively.

Natromelansonite, Na3Zr[Si7AlO19]⋅4–5H2O, was found at the Poudrette (Demix) quarry, Mont Saint-Hilaire, Quebec, Canada in a highly altered pegmatite together with a clay mineral, steacyite, polylithionite and rhodochrosite. It occurs as an outer zone of tabular crystals to 0.1 × 0.3 × 1 mm in size flattened on (001). The inner zone is made of melansonite. The mineral is grey with white powder colour and vitreous lustre. The cleavage is parallel to {010}, perfect. The Mohs hardness is 3.5. The mineral has green fluorescence under short-wave ultraviolet light. The Dcalc is 2.31 g/cm3. The infrared spectrum is reported. The composition (wt.%, average of 8 analyses) is Na2O 10.08, K2O 1.72, CaO 0.24, BaO 0.32, MnO 0.10, Al2O3 6.86, Y2O3 0.35, Yb2O3 0.55, SiO2 56.23, ZrO2 14.78, H2O 9.52, total 100.75. The empirical formula calculated on the basis of O = 23 apfu and H = 8 apfu is Na(□Na0.38Ca0.02Mn0.01)2(Na0.70K0.28Ba0.02)Σ1.00(Zr0.91Y0.02Yb0.02)Σ0.95(Si7.08Al1.02)Σ8.10O19⋅4H2O. The mineral is monoclinic, P21/m, a = 6.5156(3) Å, b = 24.061(1) Å, c = 6.9759(6) Å, β = 90.453(5)° and V = 1093.61(9) Å3 and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are: 12.02(100)(020), 6.97(89)(001), 6.51(39)(100), 3.416(37)(160), 3.062(42)($\bar{1}$61, 102, 161 and $\bar{1}$12), 3.018(38)(230 and 042), 2.864(40)(240 and 132). The crystal structure, solved and refined from single-crystal X-ray diffraction data (R1 = 0.042), is based on a double sheet of tetrahedra (T) and a sheet of octahedra (O) that alternate along the [010] direction forming a TOT structure typical for members of the rhodesite mero-plesiotype series.

Among the minerals found in meteorites, there is none which has attracted the general notice to such a degree as the metallic nickel-iron, especially from the fact that it has hitherto never been seen for certain in any telluric rocks. Nay, so much stress was laid upon this latter circumstance, that such iron was thought never to occur here on earth without having been carried to us from the outer universe, and ever since Chladni's report on the iron-mass of Pallas, every loose block of iron lying on the surface of the ground, nay, even deeply imbedded in it, has generally been declared to be a meteorite, if it only contained a certain percentage of nickel and, which was not always the case, manifested some crystalline texture, called after the discoverer "Widmannstäitten's figures."

Magnetite is a common mineral in the Paleoproterozoic Stollberg Zn–Pb–Ag plus magnetite ore field (~6.6 Mt of production), which occurs in 1.9 Ga metamorphosed felsic and mafic rocks. Mineralisation at Stollberg consists of magnetite bodies and massive to semi-massive sphalerite–galena and pyrrhotite (with subordinate pyrite, chalcopyrite, arsenopyrite and magnetite) hosted by metavolcanic rocks and skarn. Magnetite occurs in sulfides, skarn, amphibolite and altered metamorphosed rhyolitic ash–siltstone that consists of garnet–biotite, quartz–garnet–pyroxene, gedrite–albite, and sericitic rocks. Magnetite probably formed from hydrothermal ore-bearing fluids (~250–400°C) that replaced limestone and rhyolitic ash–siltstone, and subsequently recrystallised during metamorphism. The composition of magnetite from these rock types was measured using electron microprobe analysis and LA–ICP–MS. Utilisation of discrimination plots (Ca+Al+Mn vs. Ti+V, Ni/(Cr+Mn) vs. Ti+V, and trace-element variation diagrams (median concentration of Mg, Al, Ti, V, Co, Mn, Zn and Ga) suggest that the composition of magnetite in sulfides from the Stollberg ore field more closely resembles that from skarns found elsewhere rather than previously published compositions of magnetite in metamorphosed volcanogenic massive sulfide deposits. Although the variation diagrams show that magnetite compositions from various rock types have similar patterns, principal component analyses and element–element variation diagrams indicate that its composition from the same rock type in different sulfide deposits can be distinguished. This suggests that bulk-rock composition also has a strong influence on magnetite composition. Principal component analyses also show that magnetite in sulfides has a distinctive compositional signature which allows it to be a prospective pathfinder mineral for sulfide deposits in the Stollberg ore field.

In the UK, radioactive wastes currently planned for disposal in a geological disposal facility (GDF) are intermediate-level waste, some low-level waste and high-level waste. Disposal of other materials, including spent fuel, separated uranium and separated plutonium are also included in the planning of a GDF, if such materials are classified as wastes in the future. This paper gives an overview of the radionuclide behaviour research studies of the Nuclear Decommissioning Authority Radioactive Waste Management Directorate (NDA RWMD). The NDA RWMD's current understanding of the processes that control radionuclide behaviour in groundwater and how the engineered and natural barriers in a GDF would contain radionuclides is presented. Areas requiring further work are also identified.

Scorodite from Kiura mine, Bungo, Japan, has been known for many years. However, owing to its diversity in crystallographical and optical properties as well as chemical composition from those of other localities there appears to be some doubts as to the identity of the mineral. It has even been suggested to be possibly a new mineral having a composition akin to that of scorodite. Some time ago a number of fine crystals were placed at our disposal by the courtesy of Dr. Kô, in addition to the recent acquisition by our Institute of a few rarely found beautiful druses of the mineral. It will therefore be worth while to describe some of its main features in detail.

During the investigation of a migmatite complex near Strathy, north Sutherland, cummingtonite and gedrite were found to be common constituents of certain schists and granulites. Calcium-poor amphiboles have not hitherto been recorded from rocks of the Moine Series, and it is the purpose of this paper to give the results of the optical and chemical study of three examples of this group. The methods of separation and purification employed are described in some detail as it is considered that many of the previous analyses of these minerals are vitiated by faulty procedure. To avoid errors in separating two amphibole species, the investigated samples were taken from rocks containing a single amphibole phase. The paper concludes with a discussion of the correlation of optical properties and chemical composition of cummingtonites and gedrites.

The new mineral currierite (IMA2016-030), Na4Ca3MgAl4(AsO3OH)12·9H2O, was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with anhydrite, canutite, chudobaite, halite, lavendulan, magnesiokoritnigite, quartz, scorodite and torrecillasite. Currierite occurs as hexagonal prisms, needles and hair-like fibres up to ∼200 μm long, in sprays. The crystal forms are ﹛100﹜ and ﹛001﹜. Crystals are transparent, with vitreous to silky lustre and white streak. The Mohs hardness is ∼2, tenacity is brittle, but elastic in very thin fibres, and the fracture is irregular. Crystals exhibit at least one good cleavage parallel [001]. The measured density is 3.08(2) g cm -3 and the calculated density is 3.005 g cm -3. Optically, currierite is uniaxial (–) with ω= 1.614(1) and ε= 1.613(1) (measured in white light). The mineral is slowly soluble in dilute HCl at room temperature. The empirical formula, determined from electron-microprobe analyses, is (Na3.95A12.96Ca2.74Mg1.28Fe0.633+Cu0.13K0.08Co0.03Σ11.80 (AS11.685+Sb0.325+Σ12(O56.96Cl0.04)Σ57H30.81. Currierite is hexagonal, P622, with a = 12.2057(9), c = 9.2052(7) Å, V= 1187.7(2) Å3 and Z = 1. The eight strongest powder X-ray diffraction lines are [dobs Å(I)(hkl)]: 10.63(100)(100), 6.12(20)(110), 5.30(15)(200), 4.61(24)(002), 4.002(35)(210), 3.474(29)(202), 3.021(96)(212) and 1.5227(29)(440,334,612). The structure of currierite (R1 = 2.27% for 658 Fo > 4σF reflections) is based upon a heteropolyhedral chain along c in which AlO6 octahedra are triple-linked by sharing corners with AsO3OH tetrahedra. Chains are linked to one another by bonds to 8(4 + 4)-coordinated Na and 8-coordinated Ca forming a three-dimensional framework with large cavities that contain rotationally disordered Mg(H2O)6 octahedra. The chain in the structure of currierite is identical to that in kaatialaite and a geometrical isomer of that in ferrinatrite. The mineral is named in honour of Mr. Rock Henry Currier (1940–2015), American mineral dealer, collector, author and lecturer.

This mineral tar, which, from its elasticity, though somewhat weak, resembles elaterite, is found at the Craig Well, near Dingwall.

It is an intensely black, lustrous, sticky substance, of the consistency of tar, and from its being associated with albertite it may be looked upon as a variety of that asphalt.

A visual microphotometer depending on three polarizing screens is used to provide the primary scale for measuring the ratio of intensity between the incident and reflected beams for a prepared standard surface, which is intended for subsequent use in the ordinary procedure with the ore-microscope. A reversing mirror on the microscope stage gives reflection at quasi-normal incidence. Direct measurements on a surface of diamond confirm the validity of the Fresnel formula for a polished surface of this substance, and there is general agreement for a series of transparent bodies ranging up to 17 % reflectance. The standard is a glass-covered metallic surface with a reflectance near 50 %. For pyrite RD = 54·5 %.

57Fe Mössbauer spectroscopy has been used to determine the Mg2+-Fe2+ distribution between the two crystallographically inequivalent cation sites in hypersthenes from a stratigraphic tephra sequence of the Taupo Pumice formation, North Island, New Zealand. From these distributions and X-ray fluorescence analytical data, cooling histories were constructed using previously determined Mg2+-Fe2+ equilibrium isotherms for orthopyroxenes. The results showed that this cooling history geothermometer could be used to enable airfall and airflow tephra to be distinguished. In addition, they showed that the cooling rate of the above deposits correlated better with the deposit thickness, than with the distance of the deposit from the source.