... precursors can be efficient vehicles for tungsten in sedimentary rocks, leading to their enrichment in W and possibly later fertility with respect to igneous ore deposits. Leucoxene, a nanocrystalline mixture of Ti and Fe oxides, is an especially suitable candidate for such a vehicle. * E-mail...

.... Cassiterite: Representative analyses are shown in Table 2 . Optical zonation is reflected in the EMPA data. Growth zones rich in columbite-tantalite inclusions show up to 2 to 4 wt % Nb 2 O 5 + Ta 2 O 5 and minor amounts of Fe. Tungsten can exceed 0.1 wt %. Table 2. Representative Cassiterite EMPA...

...-dimensional kagomé networks in minerals where the kagomé node atoms are octahedrally coordinated in hexagonal tungsten bronze (HTB) arrays. Octahedral tilting, coupled with capping of the apical anions of the triangular groupings of octahedra in the HTB layers, gives rise to several important mineral groups...

... at the boundary between the W-rich and W-depleted domains. STEM energy-dispersive X-ray mapping reveals W- and Pb-enrichment along 2–3 nm-wide features defining the twin planes; W-bearing nanoparticles occur along the splays. Tungsten and Pb are both present, albeit at low concentrations, within Na–K–Cl-bearing...

... of the crystal structure ( R 1 = 0.075) gave the following data: orthorhombic, space group Pban , a = 7.2585(4), b = 25.8099(15), c = 3.8177(2) Å, Z = 2. Tewite has a new tungsten-bronze (TB)-type derivative structure. Distorted TeO 6 octahedra break TB slabs into ribbons which are displaced by ½ a relative...

... molybdenum tungsten diffusivity granitic melt Porphyry-type ore deposits, of which the majority were formed in the Phanerozoic ( Kesler and Wilkinson 2008 ), are commonly found at oceanic or continental arcs above subduction zones ( Wilkinson 2013 ). They are the primary source of copper...

...Bin Yang; Yin-he Xiang; Xiangping Gu Electron-microprobe analysis and X-ray micro-diffraction show the presence of tungsten-bearing rutile in the Jinling, Jiaojia, Linglong and Hexi gold deposits in the Jiaodong gold province. The tungsten-bearing rutile appears both in gold-bearing quartz veins...

... minerals. Tin hot spots and anomaly zones were revealed along the Volturno River and urban areas. Tungsten is the element out of the three which is best related to the presence of volcanic rocks belonging to the Neapolitan Potassic Province. * Correspondence: carmela.rezza@unina.it 13 09 2017...

... relevant to the skarn settings where the host rocks are carbonates, which in general have elevated Sr contents ( Kinsman 1969 ). In addition, the in situ Sr isotope study of scheelite from the Felbertal tungsten deposit (Austria) by Kozlik et al . (2016) shows changes in the Sr isotopic composition...

... triggered contact metamorphism at 200 MPa and 500–600°C which was sufficient to promote a vigorous hydrothermal convection cell (Noronha and Ribeiro, 1983 ; Noronha et al. , 2000 ). The Borralha ore deposit is an important tungsten deposit of Portugal second only to Panasqueira. It was mined from...

... November 2016 21 September 2017 © 2017 Mineralogical Association of Canada 2017 Orogenic gold tungsten rutile ilmenite metal availability metals source mineral recrystallization coupled dissolution–re-precipitation processes Meguma Terrane Bendigo-Ballarat Terrane...

...: c.lerouge@brgm.fr 01 12 2016 01 6 2017 06 6 2017 © 2017 E. Schweizerbart’sche Verlagsbuchhandlung Science Publishers 2017 E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers cassiterite tin indium tungsten ore deposit trace element sulfides mineral chemistry...

... spectroscopy. The principal aim of the present paper is to characterize the absorption properties of wolframite in the OH stretching vibrational region and to discuss plausible models for the incorporation of a hydrous phase into the structure of this important tungsten ore mineral. Infrared (IR...

...Dan Holtstam; Luca Bindi; Ulf Hålenius; Ulf B. Andersson Delhuyarite-(Ce) is a new mineral (IMA no. 2016-091) with ideal formula Ce 4 Mg(Fe 3+ 2 W)□(Si 2 O 7 ) 2 O 6 (OH) 2 . It is named after Juan and Fausto de Elhuyar (Delhuyar), chemists and metallurgists, who in 1783 isolated tungsten metal...

...Stefan Kreissl; Ralph Bolanz; Jörg Göttlicher; Ralph Steininger; Mihail Tarassov; Gregor Markl Abstract Hematite (α-Fe 2 O 3 ) and goethite (α-FeOOH) can incorporate considerable amounts of tungsten (W). Although W concentrations up to several wt% in hematite and goethite have been reported...

... determine the thermal pressure as a function of temperature at each volume, using a Mie-Gruneisen-Debye formalism. Together, the six parameters determine the density of each tungsten dioxide phase as a function of pressure and temperature—thus providing the total information of density, bulk modulus...