On the mineralogy of the O Casteliño spodumene pegmatite near Lalín, Galicia, Spain

[Abstract] The mineralogy of a spodumene-bearing pegmatite from northwestern Spain is briefly described. Analyses of spodumene, tantalite and wodginite are give

Platelet monoamine oxidase activity predicts alcohol sensitivity and voluntary alcohol intake in rhesus monkeys

Platelet monoamine oxidase B (MAO-B) has been proposed to be a biological marker for the properties of monoamine systems, with low activity being associated with vulnerability for high scores on personality traits such as sensation seeking, monotony avoidance, and impulsiveness, as well as for vulnerability for alcoholism. In the present study, platelet MAO-B activity was analysed in 78 rhesus macaques, and its relation to voluntary alcohol intake and behaviours after intravenous alcohol administration was observed

Carex supina

Angiosperm

Burangaite, a new phosphate mineral from Rwanda

This paper describes a new phosphate, burangaite, from the Buranga pegmatite in Rwanda. Burangaite is monoclinic with the idealized formula (Na,Ca)2(Fe2+,Mg)2Al10(OH,O)12(PO4)8 ∙ 4H2O, Z = 2. The crystals exhibit narrow, bladed prisms, elongated parallel to the b-axis. Perfect cleavage parallel to 100. Mohs' hardness 5. Streak slightly bluish. Unit-cell data: a0 25.09 Å, b0 5.048 Å, c0 13.45 Å, ß 110.91°, space group C2/c. These parameters and the indexed X-ray powder pattern (Table 1) indicate a marked relationship with dufrenite. The mineral is blue in color with y || b and c/\a = 11°, 2Va = 58°, strong pleochroism, refractive indices α 1.611, ß 1.635, γ 1.643. Common hourglass structure with a blue core and a colorless margin

The composition, physical properties and occurrence of eucryptite from the Haapaluoma pegmatite, Finland

Eucryptite has been found as nodules and aggregates up to ten centimetres in diameter from the Haapaluoma lithium pegmatite in Peräseinäjoki, western Finland. The mineral occurs as a rare accessory in postmagmatic fracture fillings and replacement bodies associated with quartz, cleavelandite and lithium silicates (elbaite, lepidolite and spodumene). Chemical analysis shows: SiO2 51.74 %, Al2O3 36.76 %, Li2O 9.70 %, Fe2O3tot. 0.99 %, CaO 0.30 %, Na2O 0.26 %, K2O 0.16 %, H2O+ 1.02 %. Electron microprobe analysis, however, indicates smaller amounts of SiO2 (47.5 %) and higher amounts of Al2O3 (39.4 %), corresponding to the nearly theoretical formula (LiAlSiO4) of the mineral. Spectrochemically analysed minor elements are given. On the basis of X-ray studies the unit cell data are: ahex = 13.473 Å, chex = 9.000 Å, Vhex = 1414.87 Å3, space group R3. The indexed X-ray powder pattern is given. The specific gravity is 2.657 and the calculated density 2.663 g/cm3. The mineral is grey or brown when altered. Some of the eucryptite specimens are polysynthetically twinned. The optical properties are ε = 1.585, ω = 1.572. Unlike eucryptite specimens from other localities, the mineral does not fluoresce in short- or long-wave UV light. Eucryptite is rare, and this is the first record of the mineral in Finland

Rankamaite, a new tantalum mineral from Kivu, Congo

Rankamaite is a new alkali tantalate found in heavy mineral concentrates from alluvial deposits, Mumba area, Kivu, eastern Congo, as water-worn pebbles up to tens of grams in weight. The mineral constitutes the matrix in which corroded grains of simpsonite, minute crystals of cassiterite and some manganotantalite and muscovite are seen. It was probably formed by alteration of simpsonite; the source rock is probably a lithium pegmatite. The chemical analysis gave: Ta2O5 69.47, Nb2O5 17.40, Al2O3 3.40, Li2O 0.11, Na2O 2.31, K2O 1.80, PbO 2.63, H2O+ 1.55, H2O- 0.35, SiO2 0.96, sum 99.98 %. After correcting for muscovite, this gives for the unit cell content (Na3.45K1.52Pb0.55Li0.34) (Ta13.75Nb6.06Al2.35) O56.52 (OH)7.48 or (Na, K, Pb, Li)5.86 (Ta, Nb, Al)22.16 (O, OH)60. The X-ray study shows that the powder pattern can be indexed on the basis of an orthorhombic unit cell, with a0 = 17.19, b0 = 17.70, c0 = 3.933 Å. If only reflections, with h + k = even, are considered, the possible space groups are C222, Cmm2, Cm2m, and Cmmm. The powder data are comparable to those of tetragonal SrTa4O11 and K2Nb8O21 and also to those of orthorhombic PbNb2O6; all these synthetic compounds are structurally related to the tungsten bronzes. The strongest X-ray lines are 4.112 (34), 3.935 (41), 3.467 (52), 3.375 (60), 3.011 (80), 2.970 (100), 1.736 (32). The colour is white to creamy-white. H is difficult to determine, but is approximately 3–4. G is about 5.5 (meas.), 5.84 (calc.). In thin section it is felt-like, somewhat resembling fibrous sillimanite. Elongation is positive, Z || c, X perpendicular to c, ns above 2.1. The name is in honour of Professor Kalervo Rankama of the University of Helsinki, who has made a major contribution to the geochemistry of tantalum and niobium. The name rankamaite was approved in advance of publication by the Commission on New Minerals and Mineral Names of the I.M.A