抄録
Valleriite- (Mg, Fe) is found in heavily serpentinized Ni-Cu ore of the Jinchuan magmatic ore deposit in Gansu Province, China. It occurs as massive or vein-like aggregates of small prismatic crystals up to 0.01×0.1mm in size together with pyrrhotite, pentlandite and a small amount of chalcopyrite. Reflection pleochroism is distinct : reflected light changes from brownish yellow to brownish gray with a blue tint. Reflectance : 12.7-13.1 (481nm), 13.8-15.0 (547), 13.5-16.0 (591), 14.1-16.0 (647). Under crossed nicol, bright bronze yellow to dark. It contains Fe, instead of Al, in its hydroxide layer, and analysis with EPMA gives the formula [Cu_<0.81>Fe_<1.16>Ni_<0.03>S_2]・1.47[Mg_<0.83>Fe_<0.17>(OH)_2]. Its X-ray diffraction pattern is well explained by a hexagonal system with the cell parameters, a=3.791A, and c=34.55A. Paragenetic texture suggests valleriite- (Mg, Fe) is an alteration product from chalcopyrite and/or cubanite at the serpentinization or later chloritization stage.valleriitemagmatic orenickel orecopper oreserpentinization
Valleriite- (Mg, Fe) is found in heavily serpentinized Ni-Cu ore of the Jinchuan magmatic ore deposit in Gansu Province, China. It occurs as massive or vein-like aggregates of small prismatic crystals up to 0.01×0.1mm in size together with pyrrhotite, pentlandite and a small amount of chalcopyrite. Reflection pleochroism is distinct : reflected light changes from brownish yellow to brownish gray with a blue tint. Reflectance : 12.7-13.1 (481nm), 13.8-15.0 (547), 13.5-16.0 (591), 14.1-16.0 (647). Under crossed nicol, bright bronze yellow to dark. It contains Fe, instead of Al, in its hydroxide layer, and analysis with EPMA gives the formula [Cu_<0.81>Fe_<1.16>Ni_<0.03>S_2]・1.47[Mg_<0.83>Fe_<0.17>(OH)_2]. Its X-ray diffraction pattern is well explained by a hexagonal system with the cell parameters, a=3.791A, and c=34.55A. Paragenetic texture suggests valleriite- (Mg, Fe) is an alteration product from chalcopyrite and/or cubanite at the serpentinization or later chloritization stage.
