A new hydrated zinc aluminium phosphate mineral has the composition ZnAl2(PO4)2(OH)2.3H2O. It has been named kleemanite. It occurred rarely both as veinlets 1–2 mm thick, and as thin layers on surfaces of cracks and small cavities in one section of the iron ore deposit at Iron Knob, South Australia. Chemical, X-ray, thermal analysis, and optical data are given.

Drugmanite occurs as rare colourless transparent platy crystals, up to 0.2 mm, aggregated in bunches, in vugs of a mineralized and silicified limestone. Hardness < 6. Crystals monoclinic, forms {001} {110}, parameters from indexed X-ray powder pattern (and monocrystal measurements): a = 11.110 (11.111) Å, b = 7.976 (7.986), c = 4.644 (4.643), β = 90°18′ (90°.41°). Space group P21/a with Z = 2 giving Dcalc = 5.55. Strongest lines are 4.63 Å (9), 3.752 (IO), 3.350 (8), 3.247 (8), 2.912 (9). Mean refractive index 1.88 from reflectance measurements. Strong dispersion r < v, optic axial plane // (olo), 2Vα = 33±2°. Electron microprobe analysis gave P 8.89, Al 0.85, Fe 6.19, Pb 59.76%, leading to Pb4.02 ( Al0.45)P4.00O17.02·3H2O or Pb2(Al0.22) (PO4)2 (OH)·H2O. Associated minerals are pyromorphite, anglesite, corkite and phosphosiderite. Named for J. Drugman, Belgian mineralogist (1875–1950).

Three groups of amphibolites within the Moine rocks of Sutherland have been analysed for twenty-six elements by XRF analysis. (1) Very rare epidotic hornblende schists within pelite, possibly derived from volcanic ash deposited penecontemporaneously with the pelite (2 analyses). (2) Major and minor bodies of ‘early Moine’ schistose garnetiferous amphibolite intruded early in the deformational sequence (41 analyses). (3) Small bodies of ‘Loch a' Mhòid metadolerite’, intruded later in the deformational sequence (23 analyses). Rare Moine ultrabasites are associated with these metadolerites and probably formed from the same magma as olivine cumulates. These ultrabasites (5 analyses) are chemically distinct from Lewisian ultrabasites (both in the basement sheets within the Moine rocks of Sutherland and in the foreland Lewisian rocks) and from the Glen Urquhart ultrabasic body (3 analyses).

Using variation diagrams it is inferred that chemical variation in these amphibolites is due largely to pyroxene and plagioclase crystallization in the early amphibolites and olivine, pyroxene, and plagioclase crystallization in the Loch a' Mhòid metadolerites and ultrabasites, followed in both cases by high-level fractionation. This has led to high values of incompatible elements in many of the early amphibolites. Although geochemical discrimination diagrams tend to give ambiguous results for many of these rocks, the early amphibolites are shown to be tholeiitic in nature with a chemistry transitional between within-plate and island-arc type basaltic magma. The Loch a' Mhòid metadolerites are mildly alkaline within-plate type basaltic magma.

The unusual assemblage ferroglaucophane-chloritoid-paragonite-garnet-muscovite-chlorite-quartz has been found in metapelites of the phyllite series, north-east of Neapolis, southern Peloponnese, Greece. The chemical compositions of the coexisting phases are given, and the physical and chemical constraints which may control the appearance of this assemblage are briefly discussed.

Small ophiolitic bodies are enclosed in the calcschists of the Piemont zone (western Alps). They have been metamorphosed in the blueschist facies during the alpine orogeny. One of them, the Roche Noire massif, includes gabbro breccias. The magmatic mineralogy of the gabbro was plagioclase + clinopyroxene + minor chromite. There was no chemical homogenization during metamorphism because of the lack of penetrative deformation and on the site of previous chromites, chromium-rich high-pressure and low-temperature minerals (jadeite, phengite, pumpellyite, and lawsonite) were formed. The Al ⇌ Cr substitution does not affect other P- and T-dependent substitutions.

Motukoreaite resembles hydrotalcite and has positively charged brucite-like layers separated by carbonate and sulphate anions and water molecules. Four phases are recognized. Phase I, the normal mineral with an 11.1 Å basal spacing, readily changes to a mixture of phase I and a partially dehydrated phase II. Phase III with a basal spacing 8.7 Å persists from 50–170°C. Phase II is a pseudo-regular interstratification of phases I and III, with a spacing 11.1 + 8.7 = 19.8 Å; second- and third-order reflections are observed. Phase IV with a 7.5 Å spacing is obtained by treating motukoreaite with sodium carbonate solution to replace SO4 by CO3 anions. Motukoreaite itself shows only slight tendency to transform to a 7.5 Å phase by heat-treatment alone. Comparison is made with the mineral carrboydite, a NiAl sulphate carbonate hydrate. The possibility is considered that sulphate anions may substitute partially in the brucite-like layers to compensate for a deficiency of hydroxyl ions.

Tomichite, (V,Fe)4Ti3AsO13(OH), a new mineral species related to derbylite, has been found in the ‘green leader’ gold lodes at Kalgoorlie, Western Australia. It is monoclinic, with space group P21/m or P21; a = 7.119 (3), b = 14.176 (5), c = 4.992 (2) Å, β = 105.05 (I)°, Z = 2. Strongest diffraction lines: 3.092 (4), 2.836 (9), 2.663 (10), 1.572 (5). Tomichite occurs as tiny euhedral crystals in quartz; associated minerals are vanadian muscovite, rutile, pyrite, and calaverite. Tomichite is black, has a black streak, lacks internal reflections, is moderately anisotropic, and has S.G. = 4.16 (meas.), 4.42 (calc.). Reflectivity values are 470 nm-15.9%, 546 nm-16.3%, 589 nm 16.6%. Microhardness is VHN 800, using 50 g load.

This paper presents wet chemical analyses of forty-one pyroxenes (thirty-nine of them new) from pyroxene granulites and a few neighbouring rocks from Swat Kohistan and the adjoining Indus Valley. The granulites, considered to be derived from plutonic norites of an island arc tholeiitic nature, constitute one of the most extensive belts of its kind in the world. The pyroxenes are not unusual in any respect but they bear a closer resemblance to metamorphic than to igneous pyroxenes crystallized from deep-seated tholeiitic magmas. The distribution of Mg, Fe, and Mn (average KDMg−Fe=0.57) and the tie-line intersections on the Wo-En join (generally from Wo80.5 to Wo76.5) between the coexisting eighteen pyroxene pairs from the granulites are discussed. Based on eight different methods of geothermometry and other considerations, it is concluded that the pyroxene granulites were metamorphosed at around 800 °C and 7 to 8 kbar.

A Miocene porphyry belonging to the sheshonite association contains 7 cm sanidine megacrysts in a groundmass of microphenocrysts of labradoritebytownite, augite, sporadic hastingsite, magnetite, sphene, K feldspar, apatite, Ca zeolite and calcite. The megacrysts (Or78–94) are enriched in BaO (≃ 2.0 wt%) and SrO relative to the groundmass. Although mineralogr and texture suggest that the megacrysts were suspended in a liquid, now represented by the groundmass, calculated liquid densities except for dry melts are less than those observed for the megacrysts and it is concluded that the original magma contained very little water. It possibly originated in a subduction zone with the main hycration taking place at shallow levels of intrusion during contact with groundwater. This produced zeolitization of the feldspars and may have played a part in the K enrichment at the margins of the sanidine megacrysts.

A nomenclature is proposed for the alluaudite and wyllieite complex series which is based on sequentially distributing the cations in the cell according to increasing polyhedral size, matching that size with increasing ionic radii of the cations. For oxidized members, the largest site may be partly occupied to empty after all the cations have been distributed. This is supported by structural study.

For alluaudites, the cell formula is X(2)4X(I)4 M(I)4M(2)8(PO4)12 and is written according to decreasing size of the discrete sites. The X(I) and X(2) sites are appended as suffixes in the trivial nomenclature, that is specific name—X(I)X(2).

For wyllieites, the cell formula is X(2)4X (1a)2X(1b)2M(I)4M(2a)4A14(PO4)12. The X(1a), X(1b), and X(2) sites are appended as suffixes in the trivial nomenclature, that is specific name--X(la) X(Ib)X(2).

The nomenclature proposed is:

Seventeen analyses are discussed (of which five are new) for alluaudite and four analyses (of which three are new) for wyllieites. Their distribution is given parenthetically above. One analysis revealed predominant Mg2+ in M(2). It is named maghagen-dortite.

Six new analyses are presented for the arrojadite family of minerals including re-examination of dickinsonite from Branchville, Connecticut. Al3+ is always present. We propose X1 Al (OH,F)(PO4)12, Z = 4, where X = large cations (K+, Ba2+, Pb2+, etc.), Y = Na1+, Ca2+, and M = Fe2+ Mn2+, Mg2+. A range of cations X, Y, M, and Al between 76.8 and 85.9 in the cell (84 for proposed formula) suggests the likelihood of some vacancies in the structure.

Georgeite, an amorphous copper carbonatehydrate, has been found in the oxidation zone of the Carr Boyd nickel deposit, Western Australia. It forms thin coatings mostly associated with malachite and chalconatronite on partly weathered tremolite rock containing disseminated copper and iron sulphides.

Physical properties: Colour light blue, streak pale blue, lustre vitreous to earthy, fracture conchoidal, soft, sp. gr. 2.55; transparent to sub-opaque (aggregates), n(NaD) = 1.593, isotropic. Amorphous to X-rays and electron beam.

Chemical microanalysis gave (wt%) CuO 54.9, ZnO 0.4, Na2O 2.7, CO2 20.8, H2O 21.7, sum 100.5. After deduction of all Na2O and corresponding amounts of CuO, CO2, and H2O as chalconatronite (12.35 wt%) the atomic ratios correspond to an empirical formula (Cu5.0, Zn0.05)(CO3)3(OH)4.12.6.3H2O, the ideal formula being Cu5(CO3)3(OH)4.6H2O.

Two different parageneses for cebollite, a rare hydrated calcium aluminium silicate, are described, both differing from all previously reported occurrences.

Cebollite forms concomitantly with natrolite from plagioclase in xenoliths of crustal material incorporated in kimberlite. The mineral also occurs as a late stage primary mineral in a phlogopite-rich kimberlite.

Tentative models for the genesis of the mineral in the environments described are proposed. It is suggested that the final stages in the crystallization of diatreme-facies kimberlite are dominated by fluids rich in lime and having a low partial pressure of CO2.

Aphanitic and fragmental alnöitic rocks from Malaita contain ultrabasic xenoliths and discrete nodules (megacrysts) of pyroxenes and garnets. Primary minerals in the alnöites are olivine (Fo85), clinopyroxene (diopside-sahlite), natro-melilite (1/3 melilite-2/3 åkermanite), phlogopite (1–9% TiO2), perovskite, spinel (ulvö spinel-magnetite series) and accessory nepheline, melanite, and apatite. Alnöite olivines and clinopyroxenes are compositionally different from those phases in the xenoliths and megacrysts. Rare earth element distribution patterns are linear and indicate strong enrichment in the light rare earths (La/Yb = 42−49). The alnöites are possible primary melts of a pyrolite-type mantle formed by approximately 4% partial melting at depths greater than 120 km, under high carbon dioxide pressures. Despite containing a mantle xenolith assemblage similar to that found in kimberlites, the host Malaita rocks are minera-logically and geochemically different from kimberlite.

Unusual clinopyroxenes were synthesized in the study of the join CaFeAlSiO6-CaTiAl2O6 in air at I atm. Clinopyroxene solid solution, hibonite solid solution, X-phase, perovskite, and corundum are present, and at subsolidus temperatures the clinopyroxene singlephase field extends up to about 19 wt% CaTiAl2O6. The CaTiAl2O6 component in the clinopyroxene however increases beyond the clinopyroxene single-phase field and attains 23 wt%. These clinopyroxene solid solutions are extremely poor in SiO2 and extremely rich in Al2O3, Fe2O3, and TiO2, and more than half of tetrahedral sites are occupied by AlIV, contravening the aluminium avoidance principle.

Burkeite (Na6CO3(SO4)2) is found as a surface mineral in the north of Kenya associated with thenardite and halite and in the Konya basin in Turkey associated with trona and halite. The cell dimensions of a natural burkeite are a = 7.070, b = 9.220, c = 5.173 Å. The Gibbs energy of burkeite is estimated in relation to other sodium carbonates and sulphates. Δ (burkeite) = 3594.2 ± 3 kJ.

A study has been made of topaz crystals showing a sectoral texture related to the growth of the crystal, and showing anomalous optical properties within the sectors. The growth surfaces responsible for the development of most of the sectors have been identified. The fluorine/hydroxyl sites in topaz are symmetrically equivalent in the solid crystal, but at a growth surface this equivalence may be lost, resulting in a reduction in the crystal symmetry and the ordering of fluorine and hydroxyl, the ordering scheme being retained once the crystal has formed. The reduction in symmetry expected to be produced by this ordering is in general agreement with the actual reduction in symmetry indicated by the optical properties. Heating of the topaz to about 950 °C results in the almost complete disappearance of the optical anomalies due to disordering, which may be related to the loss of hydroxyl from the crystal. Anomalous pyro- and piezoelectric phenomena may also be the result of ordering. Published optical and X-ray determinative curves for fluorine in topaz may give erroneous results for ordered topaz.

Fifteen widely separated occurrences of kimberlite and kimberlitic rocks are now known in south-eastern Australia. Those that have been satisfactorily dated isotopically give ages ranging from Permian to Late Jurassic. One occurrence exhibits an intimate spatial association with carbonatite. The classification of these rocks as ‘kimberlitic’ is partly based on their mode of emplacement, and particularly on the presence of crust/mantle inclusions. Compared with African kimberlitic magmas, the southeastern Australian examples have lower incompatible-element contents. These differences are interpreted as representing slightly greater degrees of partial melting of a four-phase Iherzolite assemblage at shallower depths (∼ 65 km) than typical African kimberlite magma.

Garavellite occurs in polished sections, as small aggregates, up to 200 µm across, of anhedral crystals, usually in direct contact with tetrahedrite, Sb-rich bismuthinite, chalcopyrite, and siderite. Chemical formula Fe0,80Cu0.02Sb1.13Bi0.78As0.01S4 on the basis of S = 4, or ideally FeSbBiS4.

The mineral has an orthorhombic unit cell with a = 11.439, b = 14.093, c = 3.754 Å, Z = 4; calculated density 5.64 gm/cm3. Important diffraction lines are 14.00 (m) 010, 7.08 (m) 020, 3.62 (vs) 230, 3.49 (m) 040, 3.34 (m) 320, 3.20 (vs) 121, 3.10 (m) 201, 2.98 (s) 240, 2.89 (s) 221, 2.63 (vs) 311, 2.51 (vs) 250, 2.16 (m) 421, 1.677 (m) 312. In reflected light it is grey with a brown-olive tint similar to that of tetrahedrite. Bireftectance is distinct and anisotropism is also strong, from yellowish-green to bluish grey. Vickers hardness (50 g load) 212–22 kg/mm2. Reflectance in air: 470 nm R1 = 33.5−34.7%, R2 = 40.5– 42.8%; 546 nm 32.8–34.7%, 40.2–42.0%; 589 nm 32.6– 33.7%, 39.3–41.0%; 650 nm 32.4–34.6%, 38.4–41.0%.

The mineral and name have been approved before publication by the Commission on New Minerals and Mineral Names, IMA.

Frigidite, the so-called nickel-bearing variety of tetrahedrite found at this locality, is shown to be an intergrowth of tetrahedrite and Ni-bearing minerals.

Plots of partition coefficient (mineral/matrix) against ionic radius of the elements in seventeen biotites from trachytes and rhyolites of the Euganean Hills do not show differences in the type of diagram between the biotites with tetrahedral sites completely filled by Si and Al, and those in which filling is only possible with the intervention of Fe3+ (or Ti4+) since these sites are incompletely filled by Si and Al. This behaviour seems to exclude, for the latter, the presence of Fe3+ (or Ti4+ in the tetrahedral site. Similar indications are given by structural analysis. The possibility of existence of [(OH)4]4− groups or, more probably, vacancies in these sites is therefore suggested. The consequences that these results would have on the possibility of correct calculation of the crystallo-chemical formula are discussed.

Late-stage acid pegmatites veining the predominantly ultrabasic Currywongaun-Doughruagh intrusion are frequently associated with amphibole-rich reaction borders in the adjacent wall-rocks. The chemical and mineralogical changes resulting from reaction between an acid pegmatite vein and the orthopyroxenite wall-rock are assessed from chemical analyses of rocks and microprobe analyses of the amphiboles forming the zoned reaction border. The main chemical change was the addition of H2O to the wall-rock; otherwise the formation of the anthophyllite and hornblende of the reaction border from pyroxene was virtually isochemical. Enrichment in other chemical species, notably Ca and AI, was restricted to the region close to the interface between the reactants. This inhibited style of reaction is attributed to the initial marginal crystallization of the acid pegmatite melt acting as a barrier to subsequent metasomatic interchange.