If it was gold plated, it ain't much any more. Brasso is a mild abrasive detergent and suited for copper and brass, but not gold. Especially not gold plate. Further, as gold does not typically oxidize or tarnish, what you likely saw was problems with a clear coat... that or it's a clone with gold coloring...
Go to a jeweler and get a gold specific polishing cloth.
Sent from my SAMSUNG-SM-N910A using Tapatalk