My bathroom sink appears to be made from two different kinds of marble. The top and side-surround is a medium brown-red, with off-white markings (sounds like I'm describing a pure-bred boxer) that are kind of oddly shaped, and the basin itself is an off-white, with sort of standard pale blue-gray shadings. It's all looking pretty dull and lifeless. I've tried several non-abrasives to try to gloss it up, but basically it always looks like it's dirty. Are there any special cleaners I could try, or some sort of refinisher that's designed for marble fixtures? I scoured the shelves at Lowe's and didn't find anything, and unfortunately it was at night so the guy who knows stuff wasn't there.