Pd,Hg-Rich Gold and Compounds of the Au-Pd-Hg System at the Itchayvayam Mafic-Ultramafic Complex (Kamchatka, Russia) and Other Localities

The unique minerals of the Au-Pd-Hg system in gold grains from heavy concentrates Itchayvayam placers and watercourses draining ore samples Barany outcrop at mafic–ultramafic complex (Kamchatka, Russia) were investigated. Gold contain substitution structures formed by Pd,Hg-rich low-fineness (Au0.59–0.52Pd0.24–0.25Hg0.17–0.23, 580‰–660‰) Pd,Hg-poor high-fineness (Au0.94–0.90Pd0.02–0.04Hg0.03, 910‰–960‰). Potarite (PdHg) without with impurities (Au < 7.9, Cu 3.5, Ag 1.2 wt.%), Ag-poor (Au0.91Ag0.09, 950‰), Ag,Pd,Hg-bearing middle-fineness (Au0.75Ag0.08Pd0.09Hg0.08—Au0.88Ag0.09Pd0.02Hg0.01, 820‰–930‰), minor contents Cd (Au0.51–0.55Pd0.25–0.22Hg0.21–0.16Ag0.03–0.06Cd0.01, fineness 580‰–630‰) observed as individual microinclusions outcrop. XRD EBSD study results show that is isotypic to has same structure type, but different cell dimensions. According data obtained for some deposits occurrences Pd,Hg-bearing gold, stable ternary phases solid solutions following compositions have been identified: (Au0.94–0.90Pd0.02–0.04Hg0.03), (Au0.59–0.52Pd0.24–0.25Hg0.17–0.23), Au-potarite (PdHg0.62Au0.38—Pd1.04Hg0.96—Au0.80Pd0.68Hg0.52), Au,Hg-bearing palladium (Pd0.7Au0.3Hg0.1). genesis insufficiently studied. We supposed meteoric waters or low-temperature hydrotherms rich Pd Hg could lead replacement gold. High concentrations indicate a genetic relationship rocks.