Unpolished microprobe preparate of about 0,20 x 0,12 x 0,06 mm grain of pinkish NIOBOCARBIDE from the type and only known locality worldwide completely analyzed. Part of holotype, portion of original material sold by Krantz to FMM in 1912 and collected at the beginning of XX century. This material was investigated and led to an article describing the new mineral niobocarbide from platinum placers of the Urals. — Photo: David Hospital · CC BY-SA 4.0
Niobocarbide
Niobocarbide is an IMA-recognized mineral species in the organic mineral class, with the chemical formula NbC.
It crystallizes in the cubic crystal system (space group Fm3m).
Key properties: Mohs hardness 5; specific gravity 4.65; Brownish black streak; Submetallic luster; optically uniaxial.
IMA symbol Ncb, IMA status: approved, named in 1995.
Found in hydrothermal uranium deposits (Saskatchewan, Canada); in gold deposits in metamorphosed greenstones (Kalgoorlie, Western Australia).
It is found associated with Dolomite, calcite, quartz, uraninite, pyrite, chalcopyrite, galena, ilmenite, hematite, carnotite (Saskatchewan, Canada); gold, gold tellurides.
The mineral was named to honor Dr. Thomas Brennan Nolan (1901–1992), formerly Director of the U.S. Geological Survey, Washington, D.C., USA.