No abstract available

[en] Ningyoite which is the phosphate of four-valent uranium is detected with the help of analytical electron microscopy (image examination with light in combination with electron microdiffraction and X-ray spectral microanalysis with the help of accessory ''Kvebex-5100''). An opinion that this mineral is very rare, existing in connection with the use of traditional methods of investigations (optics; roentgen) hardly usable for its detection, is disproved. It is established that in one deposits ningyoite is the only ore mineral, in the other ones it is present in association with variable quantities of uranium resin and coffinite. Fe containing ningyoite is detected for the first time

[en] A tetravalent uranium phosphate-ningyoite for the first time has been discovered in stratum epigenetic uranium deposit in the USSR. Application of electron microscopy combined with microdiffraction and micro X-ray spectral analysis promoted the discovery. The investigation has been carried out with an aid of electron microscopy supplied with the ''Kevex Ray'' goniometer and microprobe attachment. Spendle-shaped crystals of ningyoite, their fractures and more seldom-stellar concretions are discovered in finely dispersed mineral mixture of sample, selected from grey-green sandstone with spots of red iron hydrooxides. Electron cell of the crystals corresponds to the one of ningyoite, described by Muto. The discovered law of declinations, characterizes one of the spatial groups with base - centered lattice of the rhombic crystallographic system Cmmm; C222; Cmm 2, Cm2m. P, U, Ca elements have been determined in tha ratio P:U:Ca=2; 0,6-0,9; 1,4-1,4. The clarified ningyoite formula appears in the form of Casub(2-x)Usub(x)(PO₄)₂xH₂O where x <=1

[en] Uranyl phosphate is easily synthesized by adding a 0.36M solution of phosphorous acid of 60degC to a 0.5M solution of uranyle nitrate. The precipitate at pH 0.87-1.10 contains two morphologically different phases - one in the form of quadratic disks (''heavy'' phase) - the other in form of needle-crystals of size up to 0.1 mm (''light'' phase). X-ray analysis determined the ''heavy'' phase as meta-autunite, - the ''light'' phase as uranyl phosphate of composition (UO₂):(PO₄)=3:2. Uranyl phosphate is straw-coloured, its specific weight is 3.45; the luminescence is similar to that of autunite; the refraction index is Nsub(g)=Nsub(m)=1.581; pr=1.570 with a slight pleochroism from light yellow to white; the interference colours are week; the extinction is direct. The chemical analysis of two independently obtained samples of uranyl phosphate was carried out. It led to the crystallo-chemical formula (UO₂)₃(PO₄)₂ x 4,8H₂O. The symmetry and the parameters of the elementary cell of the phosphate are determined: it is a rhombic cell with a=13.11+-0.01A, b=6.98+-0.01A, c=16.91+-0.03A and Z=3. The x-ray density is rho=3.53. The DTA curve shows a higher temperature at the beginning of the dehydration: nearly 120deg compared with the first endoeffect of N-metaautunite which occurs at 50deg. The i.r. spectrum gives a lower symmetry than for N-meta-autunite. The water in the uranyl phosphate is strongly orientated and coupled to the structure. Dumontite which has a ratio (UO₂):(PO₄)=3:2 is found to have a analogous chemical composition to the uranyl phosphate. The parameters b and c are similar in both compounds. The formation of phosphate and the transformation into N-meta-autunite can take place even under natural coditions. The phosphoric analogue of troegerite has the same (UO₂)/(PO₄) ratio but differs in the water content. The structural relations of the two compounds are still unknown

[en] A wide variety of suggested crystallo-chemical formulas is typical of minerals of the phosphuranylite group. Uranyl phosphate formula for phosphuranylite are suggested containing an extra cation ((UO₂)₃(PO₄)₂)x6H₂O and containing a calcium cation. The ratio Ca:(UO₂):PO₄ in the unit of the formula varies, according to the data of various authors, within the limits 0,5:3:2; 1:3:2; 1:4:2. The authors of the article tried to resolve the crystal structure of the mineral according to its monocrystal formation. The empirical chemical formula for phosphuranylite was used: Ca((UO₂)₃(PO₄)₂(OH)₂)x6H₂O. The calculations made by the authors made it possible to find the co-ordinates of the atoms: 8 Ca, 24 U, 16 P, 112 O, 16 OH, and 48 H₂O. The calculations showed that the basic structural unit is a uranyl phosphate layer that is very similar to dumontite. The position of the layers relative to each other can be different, as a result of which the layers form the rhombic structure of phosphuranylite and the monoclinic structure of dumontite. The layer itself may undergo certain changes; this is confirmed by the discovery of three types of uranyl polyhedron is phosphuranylite and two in dumontite. The changes of the U polyhedron and the interatomic distances may be the result of the substitution of OH ions for O; variations in the OH:O ratio may result in a change of the content of the interlayer cation. The (UO₂):(PO₂) ratios must be stable, judging by the structures of phosphuranylite and dumontite. (V.Ya.)

No abstract available

[en] To fine oUt stability of the crystallic building of uranocircite (Ba[UO₂PO₄]₂xnH₂O) carried out the detail study of spectral and kinetic characteristics of luminescence spectra of the optical absorption of metauranocircite within the temperature range from -180 to + 350 deg C, and of its infrared spectra, as well. Subjected to investigations were 15 samples of monocrystals of the natural metauranocirzite differing by zone colour. Decifering of the structure of electron-vibrational spectra and the investigation of their connection with crystallochemical factors have permitted to find out that according to the series of spectroscopic characteristics metauranocirzite differs from other uranites, which practically coincide with metauranocirzite by X-ray structural parameters. Metaotenite samples are characterized by a higher degree of structure disordering in comparison with metauranocirzite samples. Thermal and mechanical action greatly distorts the symmetry of uranium-oxygen polyhedr in metaotenite and slightly changes it in metauranocircite. In the case of one-centre radiation predominance in these minerals, the J(Vsub(as))/J(Usub(s)) value, equal to 0.2 for metauranocircite and 0.45 for metaotenite, may be considered the main parameter of their difference. The results obtained confirm the existance of a considerable difference in structures of the minerals of uranite group, though the mechanism of the multicentre radiation manifests itself in all secondary uranium minerals

[en] The infrared spectra of the title compounds, as well as that of the structurally related mineral meta-autunite, [Ca(UO₂)₂(PO₄)₂.n H₂O], are reported and discussed using the available crystallographic data. The results can be considered as representative for the full group of the so-called ''torbernite''-minerals. (author)

[en] Upon visiting Kakinoki Mine, Hyogo Prefecture, in August, 1980, the author collected the green-colored mineral in square plate form adhering on the surfaces of waste ore. It was discovered that this was torbernite, the first uranium-containing mineral discovered in the area. Its deposit classified as hydatogenetic deposit, since the Kakinoki Mine being an abandoned copper mine. Torbernite exists only in blackish pelite (waste ore), and adheres on the surface and the cleavage, either as small platy crystals or their aggregate. In the blackish pelite, numerous quartz veins were observed, where torbernite occasionally appeared. The torbernite adhering on the surface and cleavage was grass-green and translucent, and the one in the quartz veins was emerald-green and transparent or translucent. The detection of torbernite in the waste ore suggests the potentiality of finding uranium in the Kakinoki Mine. (J.P.N.)

[en] Reconnaissance investigations in the Purcell Mountains of westcentral Alaska in 1977 revealed the presence of parsonite, a hydrous phosphate of lead and uranium with the formula Pb²UO²(PO⁴)²2H²O. This is the first reported occurrence of parsonite in Alaska. The parsonite occurs as a soft, yellow to chocolate brown coating closely associated with green muscovite on fracture surfaces in a shear zone in alaskite of the Wheeler Creek pluton. Thin magnetite veinlets are also present. The identification of parsonite was confirmed by x-ray diffraction. Delayed neutron analysis were run on samples of the Alaskite