Compositional and textural peculiarities of gold-rich alloys from the Merensky Reef

Gold-rich alloys with variable amounts of Pd from the Merensky Reef, Bushveld Complex, are characterized by a range of finely dispersed inclusions. The small sizes of these inclusions (median of 1.85 mu m) make fully quantitative analyses virtually impossible. Tentative interpretation of semi-quantitative microprobe analyses demonstrates the presence of atokite, kotulskite, laurite, moncheite, niggliite, paolovite, rustenburgite, sobolevskite, and sperrylite. Some inclusions appear to represent unnamed minerals. Textures and assemblages imply that these gold grains and their inclusions formed from fluids through occasional remobilisation and co-precipitation.