Palladosilicide, Pd2Si, a new mineral from the Kapalagulu Intrusion, Western Tanzania and the Bushveld Complex, South Africa
| Autor: | Chris J. Stanley, Andrew M. McDonald, Louis J. Cabri, H. R. Wilhelmij, Glenn Poirier, Nikolay S. Rudashevsky, Vladimir N. Rudashevsky, William Zhe |
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| Rok vydání: | 2015 |
| Předmět: |
Diffraction
Mineral 05 social sciences Analytical chemistry Mineralogy 010502 geochemistry & geophysics 01 natural sciences Geochemistry and Petrology Extinction (optical mineralogy) 0502 economics and business Pleochroism Chromitite 050211 marketing Chromite Crystal twinning Earth (classical element) Geology 0105 earth and related environmental sciences |
| Zdroj: | Mineralogical Magazine. 79:295-307 |
| ISSN: | 1471-8022 0026-461X |
| DOI: | 10.1180/minmag.2015.079.2.08 |
| Popis: | Palladosilicide, Pd2Si, is a new mineral (IMA 2014-080) discovered in chromite-rich samples from the Kapalagulu intrusion, western Tanzania (30°03′51′′E 5°53′16′′S and 30°05′37′′E 5°54′26′′S) and from the UG-2 chromitite, Bushveld complex, South Africa. A total of 13 grains of palladosilicide, ranging in size from 0.7 to 39.1 μm (equivalent circle diameters), were found. Synthetic Pd2Si is hexagonal, space group P62m, with a = 6.496(5), c = 3.433(4) Å, V = 125.5(1) Å3, c:a = 0.529 with Z = 3. The strongest lines calculated from the powder pattern (Anderko and Schubert, 1953) are [d in Å (I) (hkl)] 2.3658 100 (111); 2.1263 37 (120); 2.1808 34 (021); 3.240 20 (110); 1.8752 19 (030); 1.7265 12 (002); 1.3403 11 (122); 1.2089 10 (231). The calculated density for three analyses varies from 9.562 to 9.753 g cm–3. Palladosilicide is considered to be equivalent to synthetic Pd2Si based on results from electron backscattered diffraction analyses. Reflectance data in air for the four Commission on Ore Mineralogy wavelengths are [λ nm, R1 (%) R2 (%)] 470 49.6 52.7; 546 51.2 53.8; 589 51.6 53.7; 650 51.7 53.3 and the mineral is bright creamy white against chromite, weakly bireflectant and displays no discernible pleochroism or twinning. It is weakly anisotropic, has weak extinction and rotation tints in shades of blue and olive green. Electron probe microanalyses of palladosilicide yield a simplified formula of Pd2Si. |
| Databáze: | OpenAIRE |
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