Determining Ionic Gold Species in Massive Sulfide Ores

INTRODUCTIONThere has been unfailing interest in the forms of goldoccurrence in sulfides [1–3]. It was previously establishedby chemical analysis and fire assay that part of gold isinvisible and occurs mainly in nonstructural ultramicroscopic (smaller than 0.1 µm) and structural isomorphicstates [3–5]. According to [6, 7], the nonstructural formof gold corresponds to its metallic state, Au