Gold or gold alloys are plated from a solution containing Au ions (preferably as cyanide) and also ions of Co, Ni, or Fe, to which is added oxalate ions which control the amount of base metal co-deposited, or suppress it entirely. The oxalate is added in the form of oxalic acid, or acid or neutral salts of alkali metal, NH4 or Mg salts. About 1/2 oz. per gal. controls deposition, and 2 oz. per gal. prevents deposition, e.g. to maintain gold solution clean when desired, instead of forming alloys. The bath preferably contains citric acid, or salts thereof and alkali metal phosphates, and is maintained at pH 3 to 5.5 by adding inorganic bases or acids.
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