Sulfides, Sulfosalts and Sulfates in the Epithermal Au-Ag-Te Emmy Deposit (Khabarovsk Territory), Far East, Russia: Implications for the Mineralization Process

This study considers the features of the chemical composition, internal structure, and oscillatory zoning of sulfides, sulfosalts and sulfates in the epithermal high-intermediate sulfidation type Au-Ag-Te Emmy deposit (Khabarovsk Territory), Russia. In this deposit the most widespread sulfide is pyrite occurring in two generations: pre-ore pure pyrite (I) with cubic crystal habit and dimensions from 20 μm to 0.5 mm from the early barren pre-ore hydrothermal stage, and pyrite (II) of the ore stage, which is represented by (a) colloform aggregates (IIa) formed as a result of rapid precipitation from the solution, and (b) crystalline pyrite (IIb), which is precipitated due to continuous decrease in temperature. Both pyrite (II) morphological varieties contain copper (0.06-6.03 wt.%). The crystalline variety of pyrite is associated with goldfieldite, hemusite and kawazulite which were deposited during the early mineralizing event in the deposit.