Marble Bathroom Countertop Yellow Spot

by Robin
(Dallas, Georgia)

QUESTION:

The white marble countertop has yellowed a bit underneath where the water glasses are set. Is there a way to get the white back without damaging the marble?

ANSWER:

Hard to say why that is happening and thus how to keep it from recurring, except to be certain that it is indeed only water that is ever in the glass. I suppose it is possible that if that area is constantly wet with a glass on top, that water is being absorbed a bit into the marble countertop oxidizing mineral deposits in the marble (common in white marble) causing some discoloring. Just a guess.

But there could be some other substance involved that you have not identified too.

Nonetheless...

I'd recommend you clean it with 12% hydrogen peroxide. (see products page... the 3% kind in the drug store is too weak). Just pour some on and let it soak. You may also scrub the area a bit with a soft bristle brush.

If that doesn't get it all, then make and apply a poultice by mixing the 12% hydrogen peroxide with talc powder into a paste with the consistency of toothpaste. Apply the poultice to the stain 1/2 inch thick with a 1/2 inch border. Cover with plastic wrap, seal the edges with masking tape and let sit a day.

Then remove the plastic wrap, but let the poultice dry out another day before touching it. Once dry and hard, scrap off with plastic spatula and clean area with hot water. Gone? Good! If not, repeat with another poultice until it is.

Good Luck,
Ryan