Ore minerals of Kuki mine, Onan district, Shimane Prefecture, Japan: Especially on silver-bearing minerals

Abstract

Ore minerals of Kuki mine, Onan district, Shimane Prefecture, Japan, were investigated to identify silver-bearing minerals and characterize mineralization. Kuki mine is a vein-type deposit occurring in quartz porphyry. Samples were collected from dump of Oyokodani-Mabu and Mizunuki-Mabu. Wall rocks are serisitized, chloritiized and silicified. Main ore minerals are pyrite, galena, sphalerite, chalcopyrite and arsenopyrite. Silver minerals with less than 1 micron occur around galena grains in pyrite, and those with less than 2 microns occur in fissures in sphalerite. Crystallization sequence is pyrite+arsenopyrite -> sphalerite -> galena -> chalcopyrite -> pyrite -> silver minerals.