Potassium pargasite containing 3.19 wt. % K2O was found in a skarn from the islet of Einstödingen, Lützow-Holm Bay, East Antarctica, together with some high potassium pargasitic amphiboles. A positive correlation is shown between Fe2+/(Mg+Fe2+) and K/(K + Na(A)) ratios in pargasitic amphiboles suggesting that the increase of Fe2+ serve to stabilize high-K pargasites under the metamorphic conditions of the granulite facies.

In Part I (Vinograd, 2002) the relationship between temperature, composition and free energy of the diopside–jadeite solid solution was described using a CVM model. Here the same relationship is described using a combination of Redlich-Kister (RK) polynomials and Gaussian functions. The use of the Gaussians permits an accurate description of the free energy dip centred at Jd50, which is caused by the long-range ordering, while the effect of the short-range ordering can be easily modelled using the RK polynomial The simplified RK-Gaussian description is extended to the three-component diopside–jadeite–hedenbergite solid solution. The polynomial description permits an easy incorporation of the derived activity-composition relations into phase-equilibrium computation software.

The new mineral joanneumite was found at Pabellón de Pica Mountain, Iquique Province, Tarapacá Region, Chile, where it occurs as violet microcrystalline aggregates up to 2 mm in size in small cracks in a gabbroic rock, which is covered by a guano deposit. Associated minerals are salammoniac, dittmarite, möhnite and gypsum. Joanneumite is non-fluorescent and the Mohs hardness is 1. The calculated density is 2.020 g cm–3. The infrared spectrum of joanneumite shows the frequencies of NH3 and isocyanurate groups and the absence of absorptions of H2O molecules and OH– ions. The chemical composition (electron microprobe data, the hydrogen was calculated from the structural formula, wt.%) is C 20.33, N 31.11, O 28.34, Cu 17.27, Zn 0.24, H 2.82, total 100.11. The empirical formula is Cu0.96Zn0.01N7.84C5.98O6.25H9.96 and the idealized formula is CuN8C6O6H10 with the structural formula Cu(C3N3O3H2)2(NH3)2. Due to the lack of suitable single crystals the synthetic analogue of joanneumite was prepared for the single-crystal structure refinement. The crystal structure was solved and refined to R = 0.025 based upon 1166 unique reflections with I > 2σ (I). Joanneumite is triclinic, space group P1̄, a = 4.982(1), b = 6.896(1), c = 9.115(2) Å, α = 90.53(3), β = 97.85(3), γ = 110.08(3)°, V = 290.8(1) Å3, Z = 1 obtained from single-crystal data at 100 K, which are in good agreement with cell parameters from powder diffraction data of joanneumite at 293 K: a = 5.042(1), b = 6.997(1), c = 9.099(2) Å, α = 90.05(3), β = 98.11(2), γ = 110.95(3)° and V = 296.3(1) Å3. The eight strongest lines of the powder X-ray diffraction pattern are [d, Å (I,%) (hkl)] 6.52 (68) (010), 5.15 (47) (011), 4.66 (21) (100, 110), 4.35 (9) (1̄11), 3.29 (6) (1̄20), 3.22 (7) (1̄1̄1), 3.140 (100) (1̄21), 2.074 (7) (1̄32). The crystal structure of joanneumite is identical with the structure of synthetic bis(isocyanurato) diamminecopper(II).

These two minerals are analogous silver compounds with similar pseudo-hexagonal monoclinic form and similar compositions: polybasite, 8(Ag,Cu)2.(Sb,As)2S3, and pearceite, 8(Ag,Cu)2S.As2S3. Cu replaces Ag in considerable and varying amounts in both minerals, and in polybasite there may also be substantial replacement of Sb by As. However, the rather numerous existing analyses do not indicate continuous chemical variation from arsenian polybasite to pearceite, and therefore it is proper to recognize the two minerals as distinct species rather than end-members of a series.

Wollastonite at Scawt Hill, Co. Antrim, ocours as a constituent of both the exogeneous and endogeneous contactzones of the dolerite. In the former it is associated only with flint nodules in the metamorphosed chalk, in the latter, however, commonly as a minor constituent of certain of the hybrid types.

In my original account a wollastonite-bearing augite-dolerite from this latter zone was figured without further description in the text (plate xvII, fig. 3). In examining the optical characters of wollastonites associated with hedenbergite, I had occasion to turn again to the wollastonites of this particular rock type.

As indicated in the explanation of the figured section (loc. cir., p. 467), the dolerite is built essentially of sharply zoned brown titanaugite, labradorite, wollastonite, iron-ores, interstitial thomsonite, analcime, and accessory sphene. In this aggregate wollastonite forms subidiomorphic crystals averaging 1 ram. in size, and from a series of sections its predominant forms can be readily made out.

Levantite, with the end-member formula KCa3(Al2Si3)O11(PO4), is the phosphate analogue of latiumite, KCa3(Al3Si2)O11(SO4, CO3) found in gehlenite–wollastonite hornfels on Har Parsa, Negev Desert, Israel. Levantite forms later zones on long-prismatic crystals of latiumite. Rarer homogeneous colourless levantite crystals up to 0.2 mm long and with mean composition (K0.94Ba0.01Na0.01□0.04)Σ1.00(Ca2.96Mg0.03)Σ2.99{(Si2.69Al2.06Fe3+0.16P0.06)Σ4.97O11}[(PO4)0.65(SO4)0.35]Σ1.00 were noted. Minerals of the levantite–latiumite series are associated with gehlenite, wollastonite, clinopyroxene of the esseneite–diopside series, anorthite and Ti-bearing andradite. Levantite crystalises in space group P21 with unit-cell parameters a = 12.1006(9) Å, b = 5.1103(4) Å, c = 10.8252(9) Å, β = 107.237(8)°, V = 639.34(9) Å3 and Z = 2. The structure of levantite is analogous to latiumite. It is formed by tetrahedral hybrid zweier double layers [(Si,Al)10O22] connected by Ca atoms. Three Ca atoms linked to different double layers are bridged over by (PO4) and minor (SO4) groups. K atoms reside in the cavities between two superimposed zweier double layers. The measured micro-indentation hardness of levantite gave VHN50 = 580(19) (mean of 14), range 550–611 kg/mm2, which correlates with 5 on the Mohs scale. Cleavage is good on (100). Twinning on (100) is polysynthetic or simple. The calculated density is 2.957 g cm–3. Levantite is optically negative with α = 1.608(2), β = 1.618(2), γ = 1.622(2) (λ = 589 nm), 2Vmeas. = 70(5)° and 2Vcalc. = 64.3°. Dispersion of the optical axes r > v is weak; the optical orientation is: Z = b, X ^ c = 22–27°; and it is non-pleochroic. Minerals of the levantite–latiumite series from Israel show characteristic Raman spectra with the main bands at 994 cm–1 [ν1(SO4)2–] and 945 cm–1 [ν1(PO4)3–]. The band intensity ν1(PO4)3–/ν1(SO4) ratio is well correlated with P and S contents in the investigated minerals. The strongest lines in the powder diffraction pattern [dobs, Å (I, %) (hkl)] are: 3.0762(100)(310), 2.8551(96)($\bar 2$13), 2.9704(92)($\bar 3$12), 2.8573(83)(013), 2.5552(66)(020), 2.8228(48)(212), 2.8893(40)(400), and 3.0634(30)(103).

In the investigation of the system CaO–MgO–SiO2 by Ferguson and Merwin the orthositicate 3CaO.MgO.2SiO2 was not observed, and the existence of this compound was first proved in 1921 by Larsen and Foshag who detected it in a contact-altered limestone at Crestmore, California, and gave to it the name merwinite. Since then this compound has been found in contact-altered limestones at Scawt Hill, Antrim, near Neihart in the Little Belt Mts. of Montana, and at Velardeña, Mexico. The history of the recognition of merwinite as an artificial mineral is less easy to trace, but it seems that research workers on refractory bricks were the first to recognize its existence. Thus U.S.A. Patents applied for in the years 1934 and 1935 and British Patents applied for on 11.10.1935 and 19.5.1936 by Non-Metallic Minerals Inc. specify merwinite and periclase as the essential constituents of a refractory brick produced by firing mixtures of dolomite and serpentine, dolomite and sand, or impure magnesite and dolomite at temperatures varying between 2700° and 2900° F.

Noélbensonite, a new mineral, is the barium manganese analogue of lawsonite. It is described from the Woods ornamental rhodonite mine, 30 km NNE of Tamworth, New South Wales, Australia, where it occurs as aggregates of blocky to sometimes lamellar crystals ranging from a few micrometres to (rarely) 100 µm in length. It replaces NaMn amphibole, namansilite, and pectolite, and also occurs as tiny monomineralic veinlets 0.05–0.25 mm thick. Rare euhedral crystals are dominated by {100} and {011}, with (011) ^ = 68°. The mineral is orthorhombic, space group apparently Cmcm; a = 6.325(1), b = 9.120(1), c = 13.618(1) Å, V = 785.6(1) Å3, with a : b : c = 0.694 : 1 : 1.493. Noélbensonite is brittle, fracture irregular, Mohs hardness about 4, cleavage and twinning not observed, colour dark brown, streak paler yellow-brown, lustre earthy on some veinlet surfaces to brilliantly vitreous, calculated density 3.87 g/cm3, refractive indices α = 1.82(1),β (calculated from 2V) = 1.835(10), γ = 1.85(1), biaxial negative 2Vα = 46°(3°), strong dispersion r > v, straight extinction to plane of flattening, {100}, α ∥ c, β ∥ b, γ ∥ a with pleochroism in very thin sections: α = orange yellow, β = orange, γ = brownish orange, absorption γ > β ⇐p; α. The average of 23 electron microprobe analyses (wt.%) is SiO2 26.02, Al2O3 0.17, TiO2 0.01, Fe2O3 0.19, Mn2O3 34.76, CaO 0.31, Na2O 0.14, BaO 29.08, SrO 1.51, H2Ocalc 7.87, total 100.06, leading to the simplified formula . Up to 15% Sr and 9% Ca substitute for Ba in the large-cation sites. The strongest lines in the X-ray powder diffraction pattern are [(Iobs) dobs/Å hkl] (100) 4.85 111; (50) 4.557 020; (59) 4.322 021; (77) 3.416 113,004; (80) 2.869 202; (47) 2.849 114; (82) 2.729 024; (45) 2.543 132; (48) 2.428 222; (38) 2.255 223,041. The name is for William Noél Benson (1885–1957), in honour of his classic researches in the New England Fold Belt and of his tenure of the Chair of Geology at the University of Otago.

The single-crystal X-ray structure of a sulphate-bearing buttgenbachite, Cu36Cl7.8(NO3)1.3(SO4)0.35(OH)62.2.5.2H2O, from Likasi, Democratic Republic of Congo, has been determined at 100 and 288 K. The basic framework of the structure is the same as has been previously reported for buttgenbachite, except for the identification of a hydrogen-bonded chloride ion (occupancy 0.6) at the origin instead of a Cu ion with partial occupancy. The nature of nitrate positional disorder along channels in the c direction and how this relates to the presence of other species such as chloride ions and water molecules and, most importantly, sulphate ions has been elucidated. One nitrate ion, with an occupancy of 0.18, lies at 2/3,l/3,l/4 and shares the site with a chloride ion (occupancy 0.30) and also a sulphate ion (occupancy 0.09); a second nitrate, with an occupancy of 0.24, lies at 2/3,1/3,0.084 and shares the site with a water molecule (occupancy 0.06). As a result, a formula of Cu36Cl7.8(NO3)1.3(SO4)0.35(OH)62.2.5.2H2O is obtained. Re-refinement of deposited data for a supposed connellite crystal from the Toughnut mine,Tombstone, Arizona gives a related, but different, pattern of anion substitution. No sulphate could be detected in the structure and it is evident that this structure refers to buttgenbachite. A nitrate nitrogen atom and a chloride ion are disordered at 2/3,l/3,l/4, the overall site being fully occupied. A chloride ion with ∼0.5 occupancy is sited at the origin and the formula Cu36Cl7.9(NO3)1.1(OH)63.4H2O is indicated. Re-refinement of a deposited data set for another buttgenbachite crystal from the Likasi mine reveals a partially occupied nitrate centred at 2/3,l/3, z and a partially occupied chloride at 2/3,l/3,l/4. Either 0.5Cl–, OH–, H2O or H3O+ is located at the origin. If the latter is the case, the stoichiometry for this buttgenbachite is Cu36Cl6.5(NO3)1.5(OH)64.5.5H2O. The present study has highlighted the fact that a range of compositions for buttgenbachite exists, depending on the pH and relative activities of chloride, nitrate and sulphate ions in solutions from which the mineral crystallizes.

Pyrrhotite Fe1–xS is the main sulfide component of platinum-group element (PGE) ores and commonly contains from a few tenths to a few dozen ppm of disseminated Pt. Here we report an X-ray absorption spectroscopy investigation into the state of Pt in synthetic pyrrhotite in combination with theoretical spectra modelling. The pyrrhotite crystals were obtained by means of the salt flux technique, using a eutectic mixture of alkali metal halides as the transport media. Analysis of the chemical composition of synthesised crystals showed that an increase of the temperature and sulfur fugacity yields higher concentrations of Pt in pyrrhotite. The Pt content reached 0.6 wt.% at the maximum temperature and sulfur fugacity (t = 720°C, log $f_{{\rm S}_ 2}$ = –0.1) achieved in a Pt-saturated system. X-ray absorption near-edge structure (XANES) analysis of Pt L3-edge spectra revealed that Pt is present in pyrrhotite in the 4+ and 2+ ‘formal’ oxidation states. Theoretical modelling of XANES and interpretation of extended X-ray absorption fine structure (EXAFS) spectra showed that Pt4+ substitutes for Fe in the crystal lattice of pyrrhotite, whereas Pt2+ forms PtS-like clusters disseminated in the pyrrhotite matrix. Atoms of isomorphous Pt4+ are surrounded by 6 S atoms at a distance of 2.39 ± 0.02 Å. According to theoretical simulations using the FDMNES program, the second coordination sphere of the solid-solution Pt contains one vacancy in the Fe sublattice within the Fe-layer. The Pt2+S-like clusters can be considered as a quench product. High sulfur fugacity stabilises the solid-solution Pt and prevents the formation of the PtS-like clusters during cooling. The maximum content of the solid-solution Pt in pyrrhotite is ca. 50 times lower than in pyrite and can be approximated by a straight line in the log C(Pt) vs. 1/T plot, it increases from 1 ppm at 350°C to 3 wt.% at 900°C.

The mineral truscottite was discovered at the Lebong Donok mine, Benkulen, Sumatra, by Hövig in 1914. He considered it to be a hydrated calcium silicate of composition CaO.2SiO2.1/2H2O. Later work by Grutterink suggested a different formula, 2(Ca,Mg)O.3SiO2.2H2O, the water content being reduced to 1-3 molecules after drying at 120°. Grutterink noted that the composition, general character, and optical properties indicated a similarity to gyrolite. Flint, McMurdie, and Wells concluded from X-ray powder photographs that the two species were identical, although they detected quartz as an impurity in the truscottite examined. All known specimens of truscottite come from the original locality, and no further investigations have been reported.

Chemical analyses of nine K-feldspars and thirteen albites, along with their optical, physical, and X-ray data are presented. The obliquity values Δ = 12·5(d131-d13¯1) of the K-feldspars are found to be independent of the contents of silica and volatiles in the rocks. The role of temperature as the primary factor affecting the obliquity values is stressed. The relationship between the (An + Ab) content of the potassic phase of K-feldspars and 2Vα is shown diagrammatically.

Wooldridgeite, ideally Na2(P2O7)2(H2O)10, orthorhombic, a = 11.938(1), b = 32.854(2), c = 11.017(1) Å , V = 4321.2(8) Å3, a:b:c = 0.3634:1:0.3353, space group Fdd2, Z = 8, is a new mineral from Judkins Quarry, Nuneaton, Warwickshire, England. Associated minerals are calcite, chalcopyrite, bornite and baryte. It occurs as equant crystals forming rhombic dipyramids; no twinning was observed. It is transparent blue-green with a very pale-blue streak, a vitreous lustre, and does not fluoresce under long- or short-wave ultraviolet light. Wooldridgeite has a Mohs hardness of 2–3, is brittle with an irregular fracture, and has no cleavage. The calculated density is 2.279 g/cm3. In transmitted light, wooldridgeite is colourless, non-pleochroic, and shows no dispersion. It is biaxial negative with α = 1.508(1), β = 1.511(1), γ = 1.517(1), 2V(meas.) = 76.2(5), 2V(calc.) = 71(10)8, X = b, Y = c, Z = a. The strongest five reflections in the X-ray powder diffraction pattern are [d(Å), (I), (hkl)]: 8.23(30)(040), 6.52(100)(131), 4.05(40)(260), 3.255(40)(262); 2.924(40)(371). Electron-microprobe analysis of wooldridgeite gave P2O5 39.37, CuO 20.24, MgO 0.24, CaO 7.73, Na2O 8.33, K2O 0.17, H2O(calc.) 24.72, sum 100.80 wt.%; the corresponding unit formula (based on 24 anions) is (Na1.96K0.03)Ca1.00(Cu1.85Mg0.04)P4.04O14(H2O)10 where the H2O groups were assigned from knowledge of the crystal structure; the infrared absorption spectrum also indicates the presence of H2O in the structure. The mineral is named for James Wooldridge (1923–1995), a fervent amateur mineral collector who discovered this mineral.

In December, 2007, after 30 years of operations, the mine of Meirama ceased extraction of brown lignite. Since then operations have begun which will lead to the formation of a big mining lake (~2 km2 surface and up to 180 m deep) after controlled flooding of the open pit. In the process of flooding, both surface and ground waters are involved, each with their own chemical signature. According to the information available, the diversion of surface waters towards the pit hole should lead to the formation of a water body of acceptable quality. However, an unassisted flooding process could eventually form an acidic lake.

Iron oxides resulting from the corrosion of large quantities of steel that are planned to be installed throughout a deep geological disposal facility (GDF) are expected to be one of the key surfaces of interest for controlling radionuclide behaviour under disposal conditions. Over the lengthy timescales associated with a GDF, the system is expected to become anoxic so that reduced Fe(II) phases will dominate. Batch experiments have therefore been completed in order to investigate how a model reduced Fe-oxide surface (wüstite, Fe1–xO) alters as a function of exposure to aqueous solutions with compositions representative of conditions expected within a GDF. Additional experiments were performed to constrain the effect that highly alkaline solutions (up to pH 13) have on the adsorption behaviour of the uranyl (UO22+) ion onto the surfaces of both wüstite and portlandite [Ca(OH)2; representative of the expected cementitious phases]. Surface co-ordination chemistry and speciation were determined by ex situ X-ray absorption spectroscopy measurements (both X-ray absorption near-edge structure analysis (XANES) and extended X-ray absorption fine structure analysis (EXAFS)). Diffraction, elemental analysis and XANES showed that the bulk solid composition and Fe oxidation state remained relatively unaltered over the time frame of these experiments (120 h), although under alkaline conditions possible surface hydroxylation is observed, due presumably to the formation of surface hydroxyl complexes. The surface morphology, however, is altered significantly with a large degree of roughening and an observed decrease in the average particle size. Reduction of U(VI) to U(IV) occurs during adsorption in almost all cases and this is interpreted to indicate that wüstite may be an effective reductant of U during surface adsorption. This work also shows that increasing the carbonate concentration in reactant solutions dramatically decreases the adsorption coefficients for U on both wüstite and portlandite, consistent with U speciation and surface reactivity determined in other studies. Finally, the EXAFS results include new details about exactly how U bonds to this metal oxide surface.

The mineral, for which the name isokite is now proposed, occurs in the carbonatite plug which forms Nkumbwa Hill Oat. 10° 10' S. long. 32° 51' E.), 15 miles east of Isoka (pronounced Iso̅ka) in Northern Rhodesia. A preliminary account of this interesting mineral locality has already been published (Reeve and Deans, 1954) and a more detailed account is now in preparation, so that only the main features of the occurrence need be mentioned here. The carbonatite plug or pipe, 0.6 by 1 mile across and rising to a height of 1000 feet above the surrounding country, pierces granitic and micaceous gneisses which are fenitized to a distance of 500 yards from the walls of the pipe, but, unlike the classic carbonatite complexes, no intrusive alkalic rocks are exposed.