I believe it's an alloy of Copper, Silver, Zinc, and 20% gold by weight.
I’m afraid NuGold does not contain any gold, just as nickel silver
does not contain any silver. Also there is no silver in NuGold. It
is primarily an alloy of copper, zinc and I believe Magnesium. It
simulates gold in color only and is supplied in
sheet, wire and casting grain. Joe Dule