LAUSR

The exsolution texture of the Au–Ag–Cu–Pt solid solution is represented by numerous lamellae of cupreous gold in the Ag–Au–Pd matrix. On average, the lamellae contain Au–87.1 wt %, Cu–10.3 wt %, Pd–1.8 wt %, and Ag–1.1 wt %, which corresponds to the Au3Cu mineral phase. We revealed for the first time that cupreous gold lamellae were selectively replaced by high-grade gold (98 wt % Au), with a very precise inheritance of the exsolution texture. The substitution occurred due to the impact of epigenetic solutions on native gold with the removal of relatively mobile components.