No abstract

Summary. Pure dry chlorine at 250 to 350 ~ C is shown to have no action on the principal silicate and phosphate phases of meteorites, but reacts quantitatively with the sulphide and phosphide phases and with kamacite ; taenite does not react if it contains more than about 20 to 25 % Ni; some rare meteoritic minerals have not yet been tested. Volatile chlorides (including SIC14) distil, and non-volatile chlorides can be leached out with water. Based on these observations, a method has been devised and applied to the analysis of a number of ehondrites and to the purification of olivine and pyroxene separated by physical methods. The amount of Si present in the metal of enstatite chondrites, and the distribution of P, Ga, Ge, Ti, Cr, Mn, Ca, and Mg between oxidized and non-oxidized phases can readily be determined, and some results are presented. From the limited data so far available, Co appears to be concentrated in kamacite; gallium in the metallic phase is mainly in the taenite ; germanium is strongly siderophile in the common chondrites but some is present in the silicate of the enstatite chondrites ; titanium is markedly chalcophile in the enstatite chondrites, less so in the common chondrites, and the same applies to chromium; phosphorus is present as phosphide in the enstatite chondrites, but as phosphate in the hypersthene chondrites.

SUMMARY. Claringbullite, Cu4CI(OH)7.nH20 where n is about 0"5, a new mineral, is reported as soft blue plates in cuprite from Nchanga open pit, Zambia and Kambowe, Mina M'sesa, Katanga. The mineral is hexagonal a 6-6708, c 9~I83 A, Z = 2. Optically, claringbullite is uniaxial negative with m = r782 and e = 1"78o. Indexed powder data are given together with five electron-probe analyses of the mineral.IN I973 a specimen of cuprite said to have come from the Nchanga open pit,1 Zambia, with tiny blue platy crystals on one corner, was brought to the Museum for identification by Mr. N. Wilson. The blue crystals were thought to be gerhardtite, Cu2NO3(OH)3 , but their X-ray powder pattern did not correspond to this, or any other known mineral. A match was obtained, however, with a blue mineral from Bisbee, Arizona, belonging to Dr. S. A. Williams. A few days later a blue mineral from the M'sesa mine, Kambowe, Katanga, on loan from the Sorbonne, Paris, and believed to be a new species, was X-rayed and its powder pattern found to be identical with that of the Zambian and Arizonan mineral.The Zambian and Katangan specimens form the type specimens of claringbullite, Cu4Cl(OH)7.nH20 where n is about o'5. The mineral is named for Sir Frank Claringbull, former director of the British Museum (Natural History) and Keeper of Mineralogy. The data that follow and the name have been approved prior to publication by the Commission on New Minerals and Mineral Names, I.M.A. Physical andoptical properties.Claringbullite from Nchanga occurs as a slightly divergent group of blue plates filling a cavity in quartz and malachite on cuprite. Yellow-stained quartz crystals also occur on the specimen. The Katangan occurrence consists of slightly divergent groups of soft blue plates up to I mm across, with pearly lustre, in a vug in cuprite, associated with acicular and tabular crystals of brochantite. Malachite and copper occur elsewhere on the specimen. The claringbullite plates are flattened on {oooI}; cleavage is perfect on {oooI}; distinct on { I oTo} and { 11 ]o}. Fragments from the Katangan specimen were used for the optical investigation and consist of micaceous, thin, delicate laminae with maximum dimensions from o'o5 to 0.28 mm. The mineral is uniaxial negative. In transmitted light it is pale blue with no noticeable pleochroism and coN, is r782 for sodium light. All cleavage flakes remained dark between crossed polars.A cleavage flake of size o.28 x o'I7 x o'oi5 mm was mounted on a stage rotation apparatus. When viewed edgewise it remained pale blue for the principal vibration directions, but it was not possible to determine the refractive index for the extraordinary ray using the immersion method because of the micaceous nature of the fragment. Between crossed polars the edge-on flake showed straight extinction and abnormal interference colours of dark blue rising to yellowishgreen. The yellowish-green interference colour was obtained when the o.17 mm dimensions of the cleavage flake was parallel to the axis of the microscope and was...

Apatite-rich inclusions in some basaltic rocks from eastern Australia are interpreted as mantle crystallization products of a carbonatitic/kimberlitic fluid enriched in low atomic number rare earth elements (l.r.e.e.), and are a priori evidence for mantle heterogeneity. The chondrite-normalized rare earth abundances of separated apatite, clinopyroxene, amphiboles and micas are high, with La in apatite being up to 4600 times chondrite. Apatites show a significant variation in rare earth content and in La:Lu ratios, indicating the occurrence of some crystal fractionation. The absence of europium anomalies from all mineral phases is indicative of a relatively high oxygen fugacity for the parent magma. The nature of the rare earth element distribution between mineral pairs suggests that some xenoliths represent equilibrium assemblages while some of the amphibole-bearing ones do not. The fluid from which these xenoliths crystallized would be an ideal agent for the metasomatism of upper mantle material and may account for l.r.e.e. enriched patterns of primary magmas in some alkaline provinces.

No abstract