My bathroom sink was installed over 10 years ago. It's in perfect condition and works very well. However, recently, I noticed at the drain stopper, some black is coming from it. I tried CLR around it, Comet Cleaners and Bleach. Up until 2 weeks ago the top was shiny and looked like new. It's a gold color. NOW... when I rub it I am seeing BLACK MARKS on the cloth and I don't know WHERE it is coming from.
Can you tell me where so that I can take care of this.
Thanks.

You are removing some metal. When you polish metal, microscopic amount of metal are removed. Ever polish what looks like untarnished silver? It too will show black. The "gold" color is most likely the brass base metal. Replacement lift style stoppers are easily found and replaced. HD, Lowe's and others stock them and almost all are universal.

Hi FR

Pull the stopper and clean the entire stopper including down into the drain with a toothbrush and bleach... should help.

Mark