Native tungsten from the Bol'shaya Pol'ya river valley, Prepolar Urals, Russia, and the Dodo mine, Ust–Puiva, Tyumenskaya Oblast', Russia

Stuart J. Mills¹, Pavel M. Kartashov², Anthony R. Kampf³, Mike S. Rumsey⁴, Chi Ma⁵, Chris J. Stanley⁶, John Spratt⁶,
George R. Rossman⁵, Margarita I. Novgorodova⁷

¹ Geosciences, Museums Victoria, GPO Box 666, Melbourne 3001, Victoria, Australia	³Mineral Sciences Department Natural History Museum of Los Angeles County Los Angeles, CA 90007, USA
² Institute of Geology Ore Deposits, Petrography, Mineralogy and Geochemistry (IGEM) Russian Academy of Sciences Staromonetnyi pereulok 35, 109017 Moscow, Russia
⁴Mineralogy Department, Natural History Museum Cromwell Road London, UK, SW7 5BD	⁵Division of Geological and Planetary Sciences California Institute of Technology Pasadena, CA 91125-2500, USA
⁶Natural History Museum London London, England, United Kingdom	⁷ Fersman Mineralogical Museum, Leninskiy Prospekt 18(2), Moscow 117071, Russia

ABSTRACT

Native tungsten (IMA2011–004), W, is officially described as a new mineral from gold placers in the Bol'shaya Pol'ya river valley, Prepolar Urals, Russia, associated with yttriaite-(Y) and from quartz veins at the Dodo mine, Ust–Puiva, Tyumenskaya Oblast', Russia. Tungsten forms polycrystalline grains and masses, and rarely cubo-octahedra. It is silver white to steel grey in colour, with metallic lustre and grey streak. The calculated density is 19.226 g cm –3 . The Vickers hardness (VHN₂₅) is 571.45 Kg/mm 2 . In plane polarized light, tungsten is white with a pale yellow tint and optically isotropic. Electron microprobe analyses of Bol'shaya Pol'ya river valley material provided W 99.27, Mo 0.06, Mn 0.04, Fe 0.01, total 99.38 wt%. The five strongest powder X–ray diffraction lines are [ d_obs Å(I)(hkl)]: 2.2422(100)(110), 1.5835(25)(200), 1.2929(48)(211), 1.0010(23)(310) and 0.8457(24)(321). Tungsten is cubic, Im –3 m , a = 3.1648(4) Å, V = 31.69(4) Å 3 and Z = 2.

SEM photograph of native tungsten with embedded pieces of yittria-(Y)