It’s a galvanic thing???
Gold is just very un reactive. The ring/stye anecdote is probably associated more with copper or silver content in it than gold. Assuming it’s 14 or 18 carat. I don’t know the electron a availability or capture numbers for the element off the top of my head but once you get over 20 ct you need a mixture of powerful acids to dissolve it.
US gold coinage is 22ct. I’ve found a century old ring that fineness and seen numerous dug up coins from 1800’s here and they all look like the day they were dropped. The racks of $20’s from the SS Central America looked the same as the day of their minting and IIRC all graded AU or MS.