Mineral assemblage,gold and silver occurrence and process properties of Nongruri Gold Deposit of Tibet

The mineral assemblage, gold occurrence and characteristics of process mineralogy of Nongruri Gold Deposit were discussed on the basis of geology, petrography, ore microscopy, SEM/EDS, EPMA and LA-ICP-MS results. All native gold, with fine grains and a high fineness of 992 to 996, was found in the clay minerals and between the clay minerals and quartz. The native gold is a dominant occurrence state in this deposit. Minor invisible gold was confirmed in the pyrite and arsenopyrite, and the contribution of invisible gold to the ore grade is small. All the silver was found in the phosphate minerals as micro-enclaved silver. According to the statistic results of native gold and gold-bearing minerals, the mass fractions of different ore types were estimated.