Telling the difference between a stain and an etch mark on marble is quite simple.
An etch mark typically only occurs on marble and limestone and is the result of an acidic substance, (vinegar, lemon juice, coffee or toothpaste), coming in contact with the stone and reacting with calcium carbonate. It will leave a dull spot or cup rings on polished stone.
A stain, which can happen to any stone, granite included, is the result of either organic or inorganic matter coming in contact with a stone’s surface, and leaving what can be a permanent mark.
A good rule of thumb is that etch marks are lighter in color than the stone; stains are darker in color. A poultice can help remove a stain, but will have no effect at all on an etch mark. IF you have etching you need to call in a stone restoration company to diamond hone the surfaces to remove the damage.
If you have determined you have a stain, you need to determine what caused it. Grease and rust stains seem to be the most common. Due to the porosity of natural stone, stains can occur from both the inside of the stain (rust) or from the top down (grease).
One potential solution to both of these problems is to apply a poultice to try to draw the stain out of the stone. The difficulty is that sometimes multiple applications are necessary to remove the stain most, or all of the way. That can get expensive for a customer who has to pay for a service call every time a professional comes out.
So here is our DIY recipe for a poultice. This recipe is best for rust stains. If the stain is grease, use stripper/degreaser instead of hydrogen peroxide. Once a stain is successfully removed, then you can proceed with having a professional polish the stone back to the level of shine you desire!
STONE POULTICE RECIPE:
HOW TO APPLY A POULTICE:
Note** There are several different recipes for different types of poultices that remove different types of stains. You can always adjust the recipe. For example, a stripper/degreaser can replace the peroxide when a grease stain is present. A product called Iron Out can be substituted when dealing with rust stains.
Note** Do not be afraid that you will harm your stone by working on it. The rule of thumb with poulticing is “if a stain can go in, a stain can come out.”
Note ** Remember to wear your gloves!
Good luck- and happy poulticing!