Does anyone out there know of any gold mimic alloys in the world besides Korea's aluminum bronze, the UK's two formulas, and the US's Sacajawea and Presidential coins?
The UK Threepences were brass annealed to give a bright gold-like lustre when new. I don't know about the other coins mentioned. The Pobjoy mint produced coins in "Virenium" an alloy of copper, Zinc and Nickel, which resembled gold. The Romans made coins in what they termed "Orichalcum", which resembled gold and they valued very highly. Modern understanding is this was probably Brass and came about when the copper ore contained natural Zinc. See: https://en.wikipedia.org/wiki/Orichalcum