Although there have been many publications on the fluorescence MX. of minerals in ultra-violet light, very little systematic work has yet been done in utilizing this property for the elucidation of petrological problems, The response of various minerals would seem to be entirely capricious; but the extensive work done on phosphors shows that this depends on the presence of traces of impurities. The spectacular display given by certain minerals has made a strong appeal to amateur collectors.

In 1943 the present writer made use of a fluorescent variety of zircon to assist in the subdivision of the Archaezoic gneisses and igneous rocks of the Mnsgrave Ranges in Central Australia; and after further fieldwork preliminary observations were published in 1947.

The name chlorophaeite was given by John Macceulloch in 1819 to a mineral exhibiting striking colour change on exposure which he found at Craig nan Stàrdean (=Sgùrr Mòr) in the island of Rum. Sixty years later Professor Heddle visited the type locality and redescribed the mineral, giving for the first time chemical analyses. He also noted an occurrence of the mineral in Canna. In 1908 A. Harker showed that the rock which contained the chlorophaeite belongs to the mugearites.

Records of chlorophaeite arc not always trustworthy since the term has been used somewhat loosely. Professor Heddle (loc. cit., p. 88) confirmed the occurrence at the Giant's Causeway, Co. Antrim, first recorded by Greg and Lettsom in their Manual of Mineralogy.

Optical microscopy, Raman spectroscopy and electron probe microanalyses were conducted on a migmatitic metapelite to investigate the effects of alpha radiation and subsequent alteration at the interface between uraninite inclusions and the host minerals biotite, chlorite and albitic plagioclase. The study reveals (1) anomalous colouration under the polarizing microscope; (2) pertinent changes in the characteristic Raman spectra of host phases; (3) reaction aureoles, composed of secondary phases (viz. chlorite and K-feldspar) of various sizes (∼15–45 μm) within biotite and plagioclase, respectively; (iv) K-feldspatization and sericitization of plagioclase at the grain boundaries; (5) agreement between the observed α-penetration depths and the Monte-Carlo simulation results; and (6) dissolution textures within the matrix monazites. Analysis of the compositions of the reaction aureoles in albitic plagioclase reveals a systematic distribution of K-feldspar-, LREE- and clay-rich zones; while the same in biotite is composed of secondary chlorite. The growth sequence of the secondary phases indicates an influx of a K-rich fluid, following intense radiation damage, efficiently superimposed by LREE-metasomatism and later acidic alteration. These changes took place under low-temperature (≤150°C) conditions, wherein radial cracks (within plagioclase) and cleavages/fractures (within biotite) favoured fluid infiltration-circulation into the reaction aureoles. Depletion of the LREEs from the dissolved matrix monazites and their enrichment as a discrete LREE phase within the damaged aureoles in plagioclase demonstrate micrometre-scale LREE mobility.

With potential storage of several hundred years underground in a geological disposal facility (GDF) before closure, there is a requirement for radioactive waste packages to perform adequately. Over the past 25 years, cementitous grouts based on blast furnace slag (BFS) and ordinary Portland cement (OPC), have been used in the UK to immobilize intermediate-level waste (ILW), Magnox swarf, and currently such wasteforms are in surface storage awaiting geological disposal. Magnox fuel cladding will slowly corrode when encapsulated in alkaline cementitious grouts to produce hydrogen gas and an expansive corrosion product. Expansive corrosion products may lead to degradation of the wasteform and, if extensive, could affect the container. This study investigated the acute and chronic rates of corrosion of unirradiated Magnox swarf encapsulated in a BFS/OPC grout over a range of temperatures (25, 40, 60, 75 and 90°C) for curing times of up to 2½ years. Structural product degradation starts to develop as the tensile strength of the grout is approached by the expansive forces generated. Deformation of some experimental containers was also noted. An estimate of the time taken for a grouted product to fracture from this study due to the corrosion solely of Magnox is 350 years for storage at 25°C. Although not fully described in this paper, the main cement phases were calcium silicate hydrate, portlandite and gehlenite; the main product of Magnox corrosion was brucite. The curing temperature did not affect the compositions of the Magnox metal, corrosion product or grout.

Pb-lawsonite, PbAl2[(OH)2|Si2O7]·H2O, space group Pbnm, was synthesized as crystals up to 15 μm × 5 μm × 5 μm in size by a piston cylinder technique at a pressure of ∼4 GPa and a temperature of 873 ± 10 K. Temperature-dependent powder and single-crystal X-ray diffraction (XRD) analyses partly using synchrotron radiation as well as Raman spectroscopic investigations reveal a phase transition around 445 K resulting in the Cmcm high-temperature structure. The transformation temperature is considerably higher than that of lawsonite around 273 K, which is characterized predominantly by proton order/disorder. The transition is confirmed using principal component analysis and subsequent hierarchical cluster analysis on both the powder XRD patterns and the Raman spectra. Furthermore, a non-uniform change is observed around 355 K, which is not as pronounced as the 445 K transition and apparently comes from enhanced hydrogen bonding, which stops the atom shifts in Pb-lawsonite. These are the same bonds that mainly characterize the phase transition in lawsonite around 273 K. In contrast, the structural transition of Pblawsonite at 445 K seems to originate from the interaction of the SiO4 tetrahedra and AlO6 octahedra framework with the Pb2+ cation. The structural environment of Pb2+ can be described by a 12-fold coordination above 445 K, which changes towards irregular ten-fold coordination below this temperature. An assignment of the O–H stretching Raman bands confirms moderately strong H bonds in Pb-lawsonite, whereas both strong and weak H bonds exist in lawsonite. Therefore, a further phase transition of Pblawsonite, similar to that of lawsonite around 273 K, is not expected.

Members of the KAlSi3O8-BaAl2Si2O8 feldspar series have been synthesized by hydrothermal methods. Although the products are too finely crystalline for complete detailed study, some X-ray and optical measurements have been made, together with some electron-diffraction observations.

The results presented confirm the existence of high structural states over the greater part of the series, and suggest that a simple solid-solution series is formed between the end-members at high temperatures.

Three statistical tests, depending upon the probability distribution of X-ray intensities, have been applied to orthoclase, sanidine, and albite. It is concluded that these three felspars posses centres of symmetry, justifying the assumption of holohedral symmetry made in earlier structure analyses.

Variation diagrams for the optic properties and densities of natural specimens within the series have been determined. They focus attention on two composition regions at about 45 % Cn and 65 % Cn. The significance of the first of these is uncertain, but it is suggested that the discontinuity at 65 % Cn is related to structural changes that take place at this composition.

Olivines from igneous rocks generally have low calcium contents. However, olivines crystallized from strongly silica-undersaturated magmas occasionally contain large amounts of kirschsteinite (Ki" CaFeSiO4) and monticellite (Mo: CaMgSiO4) components. The purpose of this note is to report the first natural occurrence of kirschsteinite crystals that have lamite (La: CazSiO4) in the mineralogical norm.

Two distinct habits of redledgeite are described: small black bipyramidal crystals and yellow-green fibres. The mineral is a Ba-Cr-Ti oxide rather than a Mg-Cr-Ti oxide as previously supposed. Electron microprobe analysis gave Ba1.10(Cr1.82Ti5.95 Fe0.10V0.08)Σ7.95O16 and Ba1.27(Cr2.48Ti5.49Fe0.02)Σ7.99 O16 for the black and yellow-green forms respectively. The mineral is a monoclinic hollandite-type phase, space group I2/m, with a = 10.129(2); b = 2.959(1); c = 10.135(2) Å; β = 90.05(11)° and Z = 1; calculated density for the black form is 4.413 g cm−3. The crystal structure was refined to R 6.3%, Rw 7.4% using 1017 reflections with F > 3σ(F) from a set of 1062 unique reflections. Electron diffraction studies revealed weak superlattice reflections, with a period of 2.24b due to tunnel cation ordering.

The volumes of a disordered An20 (Qod = 0.15), a disordered An78 (Qod = 0.55) and an ordered An78 (Qod = 0.81) were determined up to 9.569(10) GPa, 8.693(5) GPa and 9.765(10) GPa, respectively, using single-crystal X-ray diffraction. The volume variations with pressure for these samples are described with 4th-order Birch Murnaghan equations of state with V0 = 669.88(7) Å3, K0 = 59.7(7) GPa. K′ = 5.7(5), K″ = −0.8(2) GPa−1 for disordered An20, V0 = 1340.48(10) Å3, K0 = 77.6(5) GPa, K0′ = 4.0(3), K″ = -0.59(9) GPa−1 for disordered An78 and V0 = 1339.62(6) A3, K0 = 77.4(6) GPa, K′ = 4.2(4), and K″ = −0.7(1) GPa−1 for ordered An78. Along with data from previous studies (An0 ordered, An0 disordered and An2o ordered), the volumes for the disordered samples were found to be up to ∼0.3% larger than the ordered samples of the same composition. The disordered samples are softer than the ordered samples of the same composition by 4(1)% for An0, 2.5(9)% for An20 and essentially zero for An78. The relationship between volume increase, density decrease, and decreasing bulk modulus with increasing disorder is in accordance with Birch's Law.

A new computer code (MARVIN) has been developed for the simulation of surfaces and interfaces. The models and methodologies employed within the program are briefly discussed. One application of the code, calculating crystal morphologies, is explored using zircon, quartz and α-Al2O3 as examples. The new code enables the use of covalent type force fields and the effect of surface relaxation on the growth morphology to be calculated for the first time. It is found that relaxation does affect the attachment energy but not by a large enough amount to significantly change the growth morphology for the three examples discussed here. Finally, the calculated surface relaxation for the basal plane of α-Al2O3 is found to be in complete agreement with Hartree-Fock ab initio calculations, verifying that the potentials, which are derived from bulk properties, transfer well to this surface.

A new mineral falgarite, K4(V+4O)3(SO4)5 was discovered at the tract of Kukhi-Malik, Fan-Yagnob coal deposit, ca. 75 km N of Dushanbe, Tajikistan. The new mineral is named after the Falgar, an ancient Sogdian name for an area around the Zeravshan riverhead. Falgarite is a fumarolic mineral formed directly from a gas emitted by a natural underground coal fire. Associated minerals are anhydrite, baryte, molybdite, an unidentified Tl-vanadyl sulfate, K–Mg sulfate and an anhydrous Mg-sulfate. Falgarite forms small isometric or pseudo-octahedral individual crystals (10–60 μm) of turquoise colour and spherical aggregates up to 0.5 mm in diameter. Mohs hardness is ~ 2.5, Dmeas = 2.87(2) and Dcalc = 2.89 g/cm3. Refractive indices are: α = 1.588(3), β(calc.) = 1.600(3) and γ = 1.609(2) (590 nm). In transmitted light falgarite is transparent green with a weak pleochroism. The mineral is non-soluble in H2O and 5% HNO3 at room temperature. Infrared spectra support the absence of H2O and OH–. The chemical composition determined by electron-microprobe analysis is (wt.%): Na2O 0.55, K2O 20.76, Tl2O 1.83, VO2 29.38 and SO3 46.78, total 99.29. The empirical formula (based on 23 O apfu) is: (K3.76Na0.15Tl0.07)Σ3.98V3.02S4.99O23.0. The strongest lines of the powder X-ray diffraction pattern are [d,Å(I,%)(hkl)]: 3.20(70)(202); 3.17(80)024; 3.14(70)$\bar{2}$04; 3.01(50)$\bar{1}$51; and 2.88(100)151. Falgarite is monoclinic, P21/n, a = 8.7209(5), b = 16.1777(6), c = 14.4614(7) Å, β = 106.744(5)°, V = 1953.77(17) Å3, Z = 4 and R1 = 0.05. VO6 octahedra and SO4 tetrahedra link together by sharing corners thus forming a [(VO)3(SO4)5]4– framework. K+, Na+ and Tl+ cations are located in the channels of the framework. The synthetic K4(VO)3(SO4)5 analogue is known.

Ternary systems of 152Eu(III), bulk bentonite and ethylenediaminetetraacetic acid (EDTA) ([Eu] = 7.9 × 10–10 M; pH = 6.0–7.0) have been studied. Without EDTA, there was slow uptake in a two-stage process, with initial rapid sorption of Eu(III) (96%), followed by slower uptake of a much smaller fraction (3.0% over a period of one month). The reversibility of Eu(III) binding was tested by allowing Eu(III) to sorb to bentonite for 1–322 days. EDTA was added to the pre-equilibrated Eu bentonite systems at 0.01 M, a concentration that was sufficient to suppress sorption in a system where EDTA was present prior to the contact of Eu(III) with bentonite. A fraction of the Eu was released instantaneously (30–50%), but a significant amount remained bound. With time, the amount of Eu(III) retained by the bentonite reduced, with a slow fraction dissociation rate constant of approximately 4.3 × 10–8 s–1 (values in the range 2.2 × 10–8 – 1.0 × 10–7 s–1) for pre-equilibration times ≥7 days. Eventually, the amount of Eu(III) remaining bound to the bentonite was within error of that when EDTA was present prior to contact (4.5% ± 0.6), although in systems with pre-equilibration times >100 days, full release took up to 500 days. Europium interactions with colloidal bentonite were also studied, and the dissociation rate constant measured by a resin competition method. For the colloids, more Eu was found in the slowly dissociating fraction (60–70%), but the first-order dissociation rate constant was faster, with an average rate constant of 8.8 × 10–7 s–1 and a range of 7.7 × 10–7 –9.5 × 10–7 s–1. For both bulk and colloidal bentonite, although slow dissociation was observed for Eu(III), there was no convincing evidence for 'irreversible' binding.

Properties and possible structures of hydronium trihydrate H9O+4 and hexahydrate H15O+7 are considered. From the 2330 minerals listed in Strunz's mineralogical tables nineteen were selected that appear to contain H+.4H2O or H+.7H2O, and the possibility of discrete H9O+4 or H15O+7 groupings existing in their crystal lattice is discussed. From a crystallochemical point of view the most probable examples of hydronium hydrate compounds are layer lattice minerals like H-montmorillonite, H-vermiculite, troegerite, H-meta-autunite, sabugalite, and hewettite.

In spite of significant concerns about Hg contamination and its toxic impacts in the environment, limited studies have been carried out in Korea. The objectives of this study are to investigate the extent and degree of Hg contamination in soil, sediment, dust and sludge from various anthropogenic sources in Korea, and to understand the distribution patterns of Hg in the study areas. The anthropogenic sources of Hg contamination were divided into four major sources: (1) by-product from abandoned Au-Ag mines; (2) coal combustion; (3) cement production; and (4) industrial and domestic discharges. A calculation of enrichment factor and index of geoaccumulation for Hg in soils and sediments indicated that some samples from mining sites were enriched in Hg. In addition, Hg concentrations in marine sediments from industrial sites were above the Effects Range Median (ERM) criteria suggested by the National Oceanic and Atmospheric Administration of the United States (NOAA). Therefore, it can be concluded that samples from various sites were directly influenced by anthropogenic sources of Hg in the surface environment.

To trace the historyof anthropogenic, atmospheric Pb pollution, analyses of soils from the region and of cores from the karst Lake Vrana (Croat: Vransko jezero) on the island of Cres were performed. The area affected byPb pollution in Croatia covers most of the high-mountain karst region. Since lake sediments can act as archives of atmospheric deposition of metals (and other pollutants) a multi-element analysis as well as Pb isotopes of dated sediment core samples and palaeosoil from the catchment enabled the evaluation of Pb-pollution history. The Pb/Sc ratios and the 206Pb/207Pb ratios allowed the calculation of enrichment factors and the anthropogenic contributions of Pb during the past 4000 y. The sediments of Lake Vrana were found to be a consistent record of Pb pollution in this part of the Mediterranean region, despite the fact that the catchment lost most of its soil cover between 1404 and 1650 AD due to deforestation which caused a major change in sediment composition.

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.

In 1962 Dawson described a calcite carbonatite (specimen BD83) from the Tanzanian volcano Oldoinyo Lengai as a sövite, thus implying that at an earlier stage in its evolution this volcano had crystallized magmatic calciocarbonatites as well as the highly alkalic natrocarbonatite lava that has been erupted in more recent times. This proposition is difficult to reconcile with the currently fashionable hypothesis whereby the natrocarbonatite lava separated immiscibly from a type of nephelinite magma, most recently thought to be a wollastonite nephelinite. In 1993 Dawson sought to discredit the magmatic origin of this sövite specimen by arguing that it was derived from natrocarbonatite lava through extreme alteration (calcitization) in which process the original nyerereite was replaced by calcite in near-perfect pseudomorphs. We suggest that the arguments advanced in support of this concept are unconvincing and that the specimen is exactly what it was originally described as, namely a magmatic sövite in which the calcite crystallized from a magma rather than having replaced nyerereite. We do not seek to discredit the liquid immiscibility hypothesis but do believe that whatever process is responsible for the Oldoinyo Lengai natrocarbonatites and silicate rocks must also allow for the crystallization of calciocarbonatite.