Early paragenetic idiomorphic Co-gersdorffite crystals disseminated in the quartz lodes show similar compositions, generally containing several hundreds ppm Au, while dispersed, irregular gersdorffite grains, Ni-bearing arsenopyrite and As-bearing pyrite are considered relatively late. These late paragenetic sulfarsenide minerals commonly contain up to 2000 ppm Au, and less common Sb. The distribution of Ni, Co, As, and Au in these minerals suggests mobilization and re-distribution by infiltrating hydrothermal fluids with sufficient CO2 to form the abundant carbonate in lodes and wallrocks. The positive correlation between Ni and As in the disseminated pyrite and arsenopyrite argues for the dissolution of Ni-bearing phases in serpentinite during carbonatization and co-precipitation.
Temperature estimates based on the composition of gersdorffite, arsenopyrite and hydrothermal chlorite reflect the development of the observed mineral associations as the system cooled down from ~ 450 to 250 ¡ãC. The oxygen and sulfur fugacity (log fO2 = ? 30 and log fS2 = ? 8 bars at 350-400 ¡ãC) corresponds to the low sulfidation and oxidizing environment typical for orogenic, silica-rich ore-bearing listvenite.