Depletion gilding:
All the [golden] objects were initially subjected to “depletion gilding,” in which copper is removed from the surface through hammering, annealing, or both, producing a golden surface that belies the metal’s true contents. This gilding was later deliberately removed, bringing out the copper’s pinkish tones. “We suggest that at a particular moment, it was desirable for an object to be golden, and at a later point, it was desirable to have the gilding removed,” says Martinón-Torres. He adds that red has been associated with the feminine in the region, so objects may have been turned pink when a woman took ownership of them or when a female owner entered puberty. [“The Pink Standard,” Daniel Weiss, Archaeology (Jan/Feb 2018)]
Bonus word!
Annealing:
Annealing, in metallurgy and materials science, is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness, making it more workable. It involves heating a material above its recrystallization temperature, maintaining a suitable temperature, and then cooling. [Wikipedia]
