Yarlongite:A New Metallic Carbide Mineral

【摘要】 <正>Yarlongite occurs in ophiolitic chromitite at the Luobusha mine （29°5′N 92°5′E,about 200 km ESE of Lhasa）,Qusum County,Shannan Prefecture,Tibet Autonomous Region,People’s Republic of China.Associated minerals are:diamond,moissanite,wiistite,iridium （"osmiridium"）, osmium （"iridosmine"）,periclase,chromite,native iron,native nickel,native chromium,forsterite, Cr-rich diopside,intermetallic compounds Ni-Fe-Cr,Ni-Cr,Cr-C,etc.Yarlongite and its associated minerals were handpicked from a large heavy mineral sample of chromitite.The metallic carbides associated with yarlongite are cohenite,tongbaite,khamrabaevite and qusongite （IMA2007-034）. Yarlongite occurs as irregular grains,with a size between 0.02 and 0.06 mm,steel-grey colour,H Mohs:5（1/2）-6.Tenacity:brittle.Cleavage:{0 0 1} perfect.Fracture:conchoidal.Chemical formula: （Cr₄Fe₄Ni）_Σ9C₄,or （Cr,Fe,Ni）_Σ9C₄,Crystal system:Hexagonal,Space Group:P6₃/mc,a = 18.839（2） （?）,c = 4.4960 （9） （?）,,V = 745.7（2） （?）³,Z = 6,Density （calc.）= 7.19 g/cm³ （with simplified formula）.Yarlongite has been approved as a new mineral by the CNMNC （IMA2007-035）.Holotype material is deposited at the Geological Museum of China （No.M11650）.更多还原

【Abstract】 Yarlongite occurs in ophiolitic chromitite at the Luobusha mine （29°5′N 92°5′E,about 200 km ESE of Lhasa）,Qusum County,Shannan Prefecture,Tibet Autonomous Region,People’s Republic of China.Associated minerals are:diamond,moissanite,wiistite,iridium （"osmiridium"）, osmium （"iridosmine"）,periclase,chromite,native iron,native nickel,native chromium,forsterite, Cr-rich diopside,intermetallic compounds Ni-Fe-Cr,Ni-Cr,Cr-C,etc.Yarlongite and its associated minerals were handpicked from a large heavy mineral sample of chromitite.The metallic carbides associated with yarlongite are cohenite,tongbaite,khamrabaevite and qusongite （IMA2007-034）. Yarlongite occurs as irregular grains,with a size between 0.02 and 0.06 mm,steel-grey colour,H Mohs:5（1/2）-6.Tenacity:brittle.Cleavage:{0 0 1} perfect.Fracture:conchoidal.Chemical formula: （Cr₄Fe₄Ni）_Σ9C₄,or （Cr,Fe,Ni）_Σ9C₄,Crystal system:Hexagonal,Space Group:P6₃/mc,a = 18.839（2） （?）,c = 4.4960 （9） （?）,,V = 745.7（2） （?）³,Z = 6,Density （calc.）= 7.19 g/cm³ （with simplified formula）.Yarlongite has been approved as a new mineral by the CNMNC （IMA2007-035）.Holotype material is deposited at the Geological Museum of China （No.M11650）.更多还原