A marble countertop in the bathroom or the kitchen can become stained with usage. It's easy to remove that with a homemade DIY poultice, says the Marble Institute of America (MIA).
Here's what you need to do:
A poultice is a liquid cleaner or chemical mixed with a white absorbent material to form a paste about the consistency of peanut butter. The poultice is spread over the stained area to a thickness of about 1/4 to 1/2 inch with a wood or plastic spatula, covered with plastic and left to work for 24 to 48 hours. The liquid cleaner or chemical will draw out the stain into the absorbent material. Poultice procedures may have to be repeated to thoroughly remove a stain, but some stains may never be completely removed.
Depending on your stain, the materials you use can vary, but the powders (or absorbent material) advised by the MIA are easily found, including bicarn soda, powdered chalk and talc. The link below has all the information you need on different cleaners for the kind of stain you have as well as the full procedure to apply your poultice.
Stain Removal [Marble Institute of America]