'Invisible gold' in bismuth chalcogenides

Gold concentrations have been determined by LA-ICPMS in bismuth chalcogenides (tellurides and sulfosalts, minerals with modular structures; chalcogen X = Te, Se, and S) from 27 occurrences. Deposit types include epithermal, skarn, intrusion-related and orogenic gold. The samples comprised minerals of the tetradymite group, aleksite series, bismuth sulfosalts (cosalite, lillianite, hodrushite, bismuthinite, and aikinite), and accompanying altaite. Gold concentrations in phases of the tetradymite group range from X tend to contain lower gold concentrations than Bi2X3 minerals (tellurobismuthite and tetradymite). Cosalite and lillianite contain Au concentrations ranging up to 574 and 3115 ppm, respectively. Bismuthinite derivatives have lower Au concentrations: <2 ppm in bismuthinite and up to 542 ppm in aikinite. In our samples, Au concentrations in altaite range from