Detailed microprobe and modal data for a sample of layered, garnetiferous, quartzose paragneiss reveal significant differences in garnet-biotite Mg-Fe distribution coefficients (Kd) — and hence paleotemperatures — determined for leucocratic (modal Grt+Bt<25 vol.%) and mesocratic (Grt+Bt> 25 vol.%) layers. In leucocratic layers, lnKd determined from both the core and rim compositions of minerals shows a range of values that varies sympathetically with the absolute amount of garnet and biotite, and, as demonstrated in other studies, inversely with the distance separating both minerals. Due to the small size (<2 mm) of garnets, which facilitated diffusional re-equilibration during cooling from peak metamorphic temperature, lnKd does not correlate to modal Bt/Grt ratios. The largest garnets, which occur in mesocratic layers, nonetheless tend to preserve the most pronounced (retrograde) zoning patterns (i.e. rimward increase in Fe/Mg), consequently mineral core composition lnKd values correlate with grain diameter except where garnets contain abundant biotite inclusions. The highest Grt-Bt temperatures (∼700°C are recorded by: (1) the composition of relatively widely-separated (>0.3 mm) grains in highly leucocratic layers; and (2) the core compositions of relatively large (>1 mm), inclusion-free grains in mesocratic layers. More closely spaced garnets and biotites in leucocratic layers, and small grains in mesocratic layers, give a range of temperatures intermediate between Tmax and diffusional blocking temperatures (∼ 560°C) recorded by the rim compositions of contiguous grains.

Musgravite, Be(MgFeZn)2Al6O12, is associated with norbergite and minor chlorite in a Precambrian calcite marble within the gneissic basement in an internal part of the Caledonian mobile belt in Dove Bugt, North-East Greenland. It commonly occurs as vitreous black, idioblastic crystals (<7 mm in size) with combined rhombohedral and basal pinacoid forms. XRD data show that its space group is R3m and its unit cell dimensions are a 5.687 ± 0.002 Å and c 41.16 ± 0.02 Å. Electron microprobe and ICP-MS analyses have yielded BeO 5.51 wt.% and ranges in abundance (wt.%): Al2O3 68.74-70.63; Tot, Fe as FeO 6.76-7.89; MgO 12.17-13.98; and ZnO 3.22-4.47. ICP-MS analysis also revealed significant trace amounts of V 249 ppm, Cr 740 ppm and Ga 178 ppm. The crystallographic parameters and composition are broadly in accord with those of musgravite from the two other recorded occurrences, in Precambrian high-grade terrains in Australia and Antarctica, although mineral and rock associations in these localities differ from those in Dove Bugt. The source of beryllium in each of the musgravite occurrences is uncertain, although a metasomatic source related to granite emplacement is favoured for the occurrence in North-East Greenland.

Cossaite, ideally (Mg0.5,☐)Al6(SO4)6(HSO4)F6·36H20, was found in the altered pyroclastic breccia of an active fumarole (T about 350°C) located at the rim of the La Fossa crater, Vulcano Island, Aeolian archipelago, Sicily, Italy. Cossaite is trigonal, space group R3̄, with a = 22.010(2), c = 9.238(1) Å, V = 3875.6(6) Å3, Z = 3. It forms stout prismatic hexagonal crystals up to 100 μm in size, terminated by rhombohedral faces, and is associated with thermessaite, vlodavetsite, sassolite and salammoniac. Cossaite is colourless to white, the streak is white and the lustre vitreous. It is not fluorescent in either long-wave or short-wave ultraviolet radiation. The calculated density is 2.075 g cm–3. The mean refractive index nobs is 1.49(1) (589 nm). Chemical analysis gave MgO 1.4, A12O3 19.5, SO3 34.7, F 5.7, (H2O 40.85, from structure refinement), O=F –2.4, total 99.75 wt.%, corresponding to the empirical formula Mg0.56Al6.19S7.01H73.37F4.85O65.15 calculated on the basis of 70 oxygen plus fluorine atoms. The strongest six lines in the X-ray powder diffraction pattern [dobs(Å) (I) (hkl)] are: 4.15 (100) (140), 3.87 (70) (32̄2), 11.00 (50) (110), 4.58 (25) (131), 2.770 (20) (3̄33), 2.166 (20) (1̄8̄1). The crystal structure was refined to a final R index of 0.0349. It contains octahedral [A1(H2O)5F]2+ cations and sulphate anions interacting via hydrogen bonds to form channels running along [001], where disordered [Mg(H2O)6]2+ cations and hydrogensulphate anions are hosted.

The crystal structure of the organic mineral refikite has been determined. The mineral was found in joints in bark and wood from pine trees in the 'V Borkách' peat deposit near the town of Krásno, Slavkovský les Mountains, western Bohemia, Czech Republic. It forms white to light-yellow polycrystalline crusts or randomly intergrown, transparent, colourless, very thin, acicular crystals up to 0.2–0.5 mm long. Sometimes, colourless-to-white elongated prismatic crystals up to 1–1.5 mm in size were encountered. The mineral is soft (Mohs hardness ∼1) and very brittle, with an uneven fracture. No visible cleavage was discerned. Crystals have a greasy-to-glassy lustre; fine crystal aggregates have a pearly lustre. Refikite, empirical formula C20H34O2 or C19H33COOH, is a derivative of abietic acid. It is orthorhombic, space group P21212, with a = 22.6520(7), b = 10.3328(3), c = 7.6711(2) Å, V = 1795.49(9) Å3, Z = 4. Refikite comprises two closely related compounds based on perhydrophenanthrene. The major component has two axial methyl groups, one terminal carboxylic group and one terminal propan-2-yl (isopropyl) group joined to the three fused rings in the same fashion as in abietic acid. However, the fused ring system is fully reduced (contains single bonds only). In the minor component, the terminal propan-2-yl group is replaced by a propen-2-yl (methylvinyl) group. The crystal structure is stabilized by strong O···H–O hydrogen bonds. High-resolution mass spectroscopy (HRMS) confirmed a molecular mass of 306 and the formula C20H34O2. Hydrogen-1 and carbon-13 nuclear magnetic resonance (NMR) spectroscopy showed the presence of four methyl groups in the major component; infrared (IR), Raman and NMR spectra are consistent with the structure. The HRMS, IR and Raman spectroscopy methods confirmed the presence of a minor component containing the propen-2-yl group replacing the propan-2-yl group. This is also reflected in a shortened C15–C17 single bond metric of 1.468(6) Å shown by single-crystal X-ray analysis. The trivial name of the major component of refikite is tetrahydroabietic acid or abietan-18-oic acid. This work represents the first proof of the existence of abietic acid derivatives as naturally occurring species.

Microcrystals of platinum-group element (PGE)-bearing cobaltite occur in the Gulcari A deposit of vanadiferous titanomagnetite in the lower zone of the Rio Jacaré mafic-ultramafic layered intrusion, Brazil. Aggregates of cobaltite and sperrylite are cluster-like and developed generally along the boundary of Fe-Ti oxide grains with deuteric silicates. Our observations of cryptic zoning, compositional variability and interelement correlations are based on 37 analytical points (wavelength-dispersion spectrometry mode) of cobaltite, and indicate that Ir and Rh behave uniformly with Ni and antipathetically with Co which, in turn, correlates directly with S content. Iridium, Rh and Ni apparently substitute for Co in the As-enriched grain core, and the substitution mechanism invokes solid solution with a cattierite-type molecule: (Ni + Ir + Rh) + (AsS) = Co + (S2). The PGE-bearing cobaltite probably crystallized as a primary phase at 500 to 300°C, from microvolumes of a late fluid phase. The observed enrichment in S and decrease in the As:S ratio at the cobaltite grain margins is a reflection of the increase in sulfur fugacity (fS2) with decrease in temperature of crystallization.

The significance of metastable and equilibrium pyroxene fractionation trends in tholeiitic magmas is discussed, and the development of sector zoning and skeletal growth are considered in relation to Nakamura's (1973) hypothesis of protosites on growing clinopyroxene crystal surfaces. At the Galapagos Spreading Centre (GSC) basalts and ferrobasalts investigated behave paradoxically in that the slower-cooled basalts follow the quench trend while the faster-cooled ferrobasalts define a much closer approach to the equilibrium trend.

It is concluded that under metastable conditions fractionation trends in Ca-rich pyroxenes may be strongly influenced by textural features such as cotectic crystallization of plagioclase and the onset of liquid immiscibility, the latter leading to the development of strongly Fe-enriched ferroaugites. Even under plutonic conditions metastable crystallization can develop and severely reduce the pyroxene miscibility gap. A model for metastable crystallization is presented. These considerations are then addressed to the remarkable correspondence of the Skaergaard and Thingmuli pyroxene fractionation trends.

Brumadoite, ideally Cu3Te6+O4(OH)4-5H2O, is a new mineral from Pedra Preta mine, Serra das Eguas. Brumado, Bahia, Brazil. It occurs as microcrystalline aggregates both on and, rarely, pseudomorphous after coarse-grained magnesite, associated with mottramite and quartz. Crystals are platy, subhedral. 1—2 μm in size. Brumadoite is blue (near RHS 114B), has a pale blue streak and a vitreous lustre. It is transparent to translucent and does not fluoresce. The empirical formula is (Cu2.90Pb0.04Ca0.01)Σ2.95 (Te0.936+Si0.05)Σ0.98O3.92(OH)3.84.5.24H2O. Infrared spectra clearly show both (OH) and H2O. Microchemical spot tests using a KI solution show that brumadoite has tellurium in the 6+ state. The mineral is monoclinic, P2/m or P21. Unit-cell parameters refined from X-ray powder data are a 8.629(2) Å, b 5.805(2) Å, c 7.654(2) Å,β 0 103.17(2)°, F 373.3(2) Å3, Z= 2. The eight strongest X-ray powder-diffraction lines [d in Å,(I),(hkl)] are: 8.432,(100),(100); 3.162,(66),(2̄02); 2.385,(27),(220); 2.291,(12),(l̄22); 1.916,(11),(312); 1.666,(14),(4̄22,114); 1.452,(10),(323,040); 1.450,(10),(422,403). The name is for the type locality, Brumado, Bahia, Brazil. The new mineral species has been approved by the CNMNC (IMA 2008-028).

Munirite was found in the sandstones of Siwaliks formation of mid-Miocene to Pleistocene age. It occurs as small globular clusters of acicular crystals (2 to 3 mm long). Analysis gave V2O5 67.46, N2O 22.91, and H2O 10.26%. The X-ray powder diffraction pattern shows remarkable similarity to a synthetic compound NaVO3 · 1.9H2O (Lukacs and Strausievici, 1962).

Synthetic andradite (Ca3Fe2Si3O12) has been compressed to loading pressures >21 GPa and heated to ∼1000°C by a YAG laser in a Diamond Anvil Cell (DAC). After quenching to room temperature, X-ray diffraction of the sample, still held at 21 GPa, showed that andradite had transformed to a cubic perovskite type polymorph with a = 3.460(4) Å. Upon decompression the perovskite phase transformed into an amorphous phase. The density of the perovskite polymorph (Ca3Fe2Si3O12) is ∼13.6% greater than that of isochemical andradite at 21 GPa. Ferric iron replaces Ca2+ and Si4+ in the perovskite structure (Fe3+ + Fe3+ = Si4+ + Ca2+), giving a formula unit: (Ca,Fe3+)(Si,Fe3+)O3. The new Fe3+-rich Ca-perovskite may provide new insight into the controls on the electrical conductivity of the lower mantle.

The crystal structure of hejtmanite, Ba2Mn4Ti2(Si2O7)2O2(OH)2F2, from Mbolve Hill, Mkushi River area, Central Province, Zambia (holotype material) has been refined on a twinned crystal to R 1 = 1.88% on the basis of 4539 [|F| > 4|F|] reflections. Hejtmanite is triclinic, C1̅, a = 10.716(2), b = 13.795(3), c = 11.778 (2) ,= 90.07(3),= 112.24(3),= 90.03(3), V = 1612(2) 3. Chemical analysis (electron microprobe) gives: Ta2O5 0.09, Nb2O5 1.27, ZrO2 0.65, TiO2 14.35, SiO2 23.13, BaO 26.68, SrO 0.19, FeO 11.28, MnO 15.12, Cs2O 0.05, K2O 0.33, F 3.82, H2Ocalc. 1.63, O = F 1.61, total 97.10 wt.%, where the H2O content was calculated from the crystal-structure refinement, with (OHF) = 4 apfu. The empirical formula, calculated on the basis of 20 (OF) anions, is of the form (Si2O7)2(XO)4(XP)2, Z=4: (Ba1.82K0.07 Sr0.02)Σ1.91(Mn2.33 Zr0.04Mg0.03)Σ3.95(Ti1.88Nb0.10Zr0.02)Σ2(Si2.02O7)2O2[(OH)1.89 F0.11]Σ2F2. The crystal structure is a combination of a TS (Titanium Silicate) block and an I (intermediate) block. The TS block consists of HOH sheets (Hheteropolyhedral, Ooctahedral). The topology of the TS block is as in Group-II TS-block minerals: Ti ( Nb) = 2 apfu per (Si2O7)2 [as defined by Sokolova (2006)]. In the O sheet, five [6]MO sites are occupied mainly by Mn, less Fe2 and minor Zr and Mg, with <MOφ> = 2.198(φ = O,OH), ideally giving Mn4 apfu. In the H sheet, two [6]MH sites are occupied mainly by Ti, with <MHφ> = 1.962(φ = O,F), ideally giving Ti2 apfu; four [4] Si sites are occupied by Si, with < SiO> = 1.625 . The MH octahedra and Si2O7 groups constitute the H sheet. The two [12]Ba-dominant AP(1,2) sites, with <APφ> = 2.984(φ = O, F), ideally give Ba2 apfu. Two (1,2) and two (1,2) sites are occupied by O atoms and OH groups with minor F, respectively, ideally giving (XO)4 = ()2()2=O2(OH)2 pfu. Two (1,2) sites are occupied by F, giving F2 apfu. TS blocks link via a layer of Ba atoms which constitute the I block. Simplified and end-member formulae of hejtmanite are Ba2(Mn,Fe2)4Ti2 (Si2O7)2O2(OH,F)2 F2 and Ba2Mn4Ti2(Si2O7)2O2(OH)2F2, Z = 4. Hejtmanite is a Mn-analogue of bafertisite, Ba2 4 Ti2(Si2O7)2O2(OH)2F2.

The estimation of molybdenum and tungsten when present together has proved difficult, as is indicated by the large number of methods put forward for their determination. Many of the methods given are for one or other of these elements only, a note often being added that the presence of the other invalidates the method. The estimation of molybdate and tungstate in the mineral powellite has been briefly described by one of the authors (A. A. M.): molybdate and tungstate were precipitated as oxinates (Mo,W)O2(C9H6ON)2 and the molybdate (MoO4″) determined by measurement of the optical density at 230 mµ of a solution containing molybdate and tungstate. The amount of tungstate present was then estimated by difference. The property of the molybdate ion, MoO4″, to absorb strongly in the ultra-violet has been further investigated and it has been found that, if a wave-length of 240 mµ is chosen and the proper precautions taken, the MoO4″ ion can be estimated without significant interference by the WO4″ ion. Methods are given for the analysis of the common molybdate and tungstate minerals, together with results obtained during the course of this investigation.

A Dark brown (blackish-brown) mineral forms a thin crust on manganese ore on the specimen [B.M. 1944,35] from no. 5 orebody of the Benallt mine, Rhiw, Carnarvonshire, North Wales. This is the specimen on which the first measurable crystals of banalsite were discovered in 1944 (Min. Mag., 1945, vol. 27, pp. 63-64). The mineral occurs as closely-packed, small rosettes, at most 0"5 ram. across, and is partly coated with a thin layer of baryte. An X-ray photograph by Dr. Bannister suggested that the mineral might belong to the chlorite group. Its optical properties were determined and nothing further was done with it at the time.