by Plum on Sun Mar 30, 2008 6:24 am
White gold is not coated yellow gold, actually. It's an alloy of gold and a white metal, such as nickel or zinc. Sometimes a white gold item is rhodium plated, but not always. You'll need to ask a jeweler about whether or not yours are. If so, you'll probably just want to have the same type of plating. If you really want 14 or 18K rings you're better off buying new ones. All plating does is give you a 14k plated ring, not a 14k ring.
There's a post in this section with a recipe for homemade jewelry cleaner. That should work just fine on your rings. If not, take them to a jewelry store and ask to have them cleaned. Most will do this for free while you browse or charge just a small fee.