A hundred years after the discovery of the Merensky Reef in 1924, it is appropriate to present the new mineral andrieslombaardite in honour of Andries Frederik Lombaard who was instrumental in its discovery. Andrieslombaardite, RhSbS, was first described as an unknown mineral from placer deposits associated with the Tulameen Alaskan-Uralian type complex, British Colombia, Canada (Raicevic and Cabri, 1976) but has since been reported from several other deposits including the platiniferous Driekop, Mooihoek, and Onverwacht pipes in the eastern Bushveld Complex, South Africa. The mineral and the name were approved by the Commission on New Minerals Nomenclature and Classification (CNMNC) of the International Mineralogical Association (IMA no. 2022-076) based on data in the co-type samples from Onverwacht and a co-type sample from the Yubdo stream, Birbir River, Ethiopia. Andrieslombaardite in the Onverwacht sample is a single 8 x 20 μm grain attached to laurite in a matrix of altered silicate and Fe-oxyhydroxide minerals. In the Yubdo samples, there are many grains of pale brownish gray andrieslombaardite up to 25 x 55 μm in size, included in Pt-Fe alloys, some associated with erlichmanite, and others attached to bornite and chalcopyrite. The reflectance values (R%) measured in air and in oil at the COM wavelengths are 48.3 and 33.0 (470 nm), 49.3 and 34.0 (546 nm), 51.0 and 35.9 (589 nm), and 51.8 and 36.7 (650 nm). The colour values x, y, Y, λd, and Pe in air are 0.317, 0.322, 50.3, 580, and 3.2, and in oil are 0.319, 0.324, 35.6, 579, and 4.5. The composition of andrieslombaardite is ideally RhSbS, but it contains variable amounts of Fe, Pt, Pd, and Ir that may substitute for Rh. The mineral is cubic with unit-cell dimensions of a = 6.0278(4) Å, V = 219.01(6) Å3 and Z = 4. It was synthesised at 400 and 550°C using stoichiometric elemental amounts. It is a member of the cobaltite group. The mineralisation of the intrusive dunite pipes was probably introduced at high temperatures, under magmatic conditions. The primary assemblages were to a certain degree overprinted and redistributed by low-temperature hydrothermal fluids. The Pt-Fe alloys from Yubdo containing PGM inclusions such as andrieslombaardite in the Yubdo-Alaskan-type complex were formed at some post-magmatic stage owing to PGE remobilisation during hydrothermal or metamorphic episodes.

A new program capable of rapidly and accurately reducing a two-dimensional X-ray diffraction pattern obtained from a Debye–Scherrer or Gandolfi camera to a quantitative digital diffractogram is described. By implementing geometric optimization routines based on the symmetry and sharpness of diffraction lines, the optimal configuration of the camera, X-ray path, and sample can be determined, thus providing the best possible set of integration parameters. Results for NIST standard reference materials 640c (Si) and 676 (Al2O3) are included to illustrate program functionality.

Ungavaite, Pd4Sb3, is a new intermetallic mineral species discovered in the Mesamax Northwest deposit, Cape Smith fold belt. Ungava region, northern Quebec. It is associated with monoclinic pyrrhotite, pentlandite, chalcopyrite, galena, sphalerite, cobaltite. a chlorite-group mineral and magnetite. Associated precious-metal minerals include another new mineral species, naldrettite (Pd2Sb), sperrylite, sudburyite, michenerite, Au-Ag alloy, altaite, petzite (Ag3AuTe4) and hessite (Ag2Te). Ungavaite occurs as rare anhedral grains with inclusions of Au-Ag alloy or with attached chalcopyrite and a chlorite-group mineral. Grains of ungavaite vary in size (equivalent circle diameter) from ca. 36 to 116 mu m, with an average of 73 mu m (n = 4). Neither cleavage nor fracture was observed. It is distinctly anisotropic, non-pleochroic, has weak bireflectance and does not exhibit discernible internal reflections. Ungavaite appears bright creamy white in association with pentlandite, pyrrhotite, the chlorite-group mineral and chalcopyrite. Reflectance values in air (and in oil) for R-1 and R-2 are: 50.2, 50.5 (37.6, 38.0) at 470 nm, 55.6, 55.9 (43.2, 43.5) at 546 nm, 57.9, 58.3 (45.9, 46.3) at 589 nm and 60.2, 60.7 (48.1, 48.5) at 650 nm. The average result of 16 electron-microprobe analyses on one particle is: Pd 54.53, Fe 0.13, Te 0.09, Sb 44.59, Bi 0.42, Hg 0.19, and As 0.20, total 100.15 wt. %, corresponding to empirical formula (based on seven atoms) Pd-4.062(Sb2.893Fe0.017Bi0.017Hg0.006Te0.005)(Sigma 2.938), ideally Pd4Sb3. The mineral is the Pd-dominant analogue of genkinite. It is tetragonal, crystallizing in one of the possible space-groups P4(1)2(1)2, P4(1)22, P4(3)2(1)2, P4(2)2(1)2, or P4(2)22. Cell dimensions are: a 7.7388 (4), c 24.145(1) angstrom, with V = 1446.02(1) angstrom(3) and Z = 8. The calculated density is 7.264(1) g/cm(3). The strongest six lines in the X-ray powder-diffraction pattern [d in angstrom(I)(hkl)] are: 3.008(90)(008), 2.268(100)(134), 2.147(30)(230), 1.9404(60)(400), 1.2043(30)(2218, 452), 1.2002(30)(624). The mineral formed in a narrow (Pd + Sb)-rich zone separating massive and disseminated sulfides. It is likely a product of the hydrothermal remobilization of Pd (and possibly Sb) from the pre-existing massive sulfides. Phase relations suggest that ungavaite developed at a temperature below 400 degrees C, possibly through a solid-state order-disorder transformation.

In the title compound, C8H5NO4, the heterocycle is planar within 0.02 Angstrom, and the nitro group plane makes an angle of 10.0(1)degrees to it. Dipolar interactions and possible weak C-H ... O hydrogen bonding feature in the crystal packing. In a series of phthalides, bond lengths in the lactone ring can be related to substituent effects; in the title compound, the nitro group exerts less influence than it does in the homologous 3-nitromethylenephthalide.

A multidisciplined approach to developing 3D target diagrams and their associated tolerances provides a cost-effective method for designing horizontal wells. The key to this approach is that the diagram quantifies and communicates the uncertainty of the target boundary conditions to others involved in designing and drilling a well. Field examples show how a multidisciplined team creates a 3D target diagram. The preliminary 3D diagram is used to examine the combined uncertainty in the position of the features constraining the target. To maximize the target size, the team must decide on the relative importance of each constraining feature and assign target tolerance limits. The final target diagram minimizes both risk and cost to produce the optimum well design.

Abstract The prediction of a safe mud weight is important when drilling highly inclined or horizontal wells through permeable, poorly consolidated formations. If the mud weight used to drill these types of wells is too high, differential sticking of the drill string will occur. If the mud weight is too low, it is possible that the well bore will collapse. The standard linear elasticity borehole stability analysis methods used by many in industry predicts an unnecessarily high mud weight to prevent borehole collapse, while the safe mud weight is significantly lower. This paper describes a new core-based well stability analysis for horizontal or highly inclined wells in weak formations. New procedures to measure core strength and deformation and the numerical procedure to calculate the well stability for a highly non-linear formation are discussed. Field data and experiences are also included to validate the non-linear borehole stability analysis.