Dunno, but try Magic Eraser.

I have a gorgeous slate-topped coffee table that I inherited from my folks (I remember bumping into the pointy corners as a wee babe) and I use mineral oil on once a year to clean and shine it up. I use the oil from Ikea that you can use on butcher blocks and it works great. Just rub it on, wait a few and buff off the excess. Easy peasy!

awesome! i will try it for sure. thanks!
paule (not pauline...)