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

Stuart J. Mills1Pavel M. Kartashov2, Anthony R. Kampf3Mike S. Rumsey4Chi Ma5Chris J. Stanley6John Spratt6
George R. Rossman5Margarita I. Novgorodova7

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

7 Fersman Mineralogical Museum,
 Leninskiy Prospekt 18(2), Moscow 117071, Russia


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 [ dobs (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) , V = 31.69(4) 3 and Z = 2.

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