Ore minerals down to the nanoscale: Cu-(Fe)-sulphides from the iron oxide copper gold deposit at Olympic Dam, South Australia

Schematic showing bornite-digenite phase diagram in terms of temperature (T) versus mol% bornite (Bn) after Morimoto and Kullerud (1966). Dg: digenite; na = superstructure of an 'n' type. Interpretation of cooling paths for Bn-chalcocite (Cc) formation, according to two scenarios: (i) from above the consulate solvus point (dark purple) and (ii) from below the solvus (blue). Representative phase intergrowths (SE images labelled 1-3) showing evidence for unmixing.