Etch Marks — Those Aren’t Water Stains!


Etching on marble, limestone, travertine and all the calcium based stone is the result of a chemical reaction that occurs when acid comes in contact with a surface. Etch marks on stone surfaces resemble water spots or worn polish.


Seemingly innocent items like tooth paste, mouthwash, orange juice, coffee, vinegar, wine, perfumes, tomato products, mustard and many soft drinks are highly acidic and will etch, discolor, or even scratch. Acid resistant stones like most granite, slate and sandstone will typically not etch, nor will ceramic and porcelain tile. Sealing will give you more time to wipe up a spill, but it cannot stop the chemical reaction that may leave a dull mark. Remember to always use coasters and place mats on these acid-sensitive stones.


The only way to remove Etch Marks is by diamond polishing. Sometimes just the spot can be re-polished. Give us a call and we’ll come out to assess your needs.



How to Test if Your Stone is Already Sealed


Take a quick test, water-repellency test to see if your stone has already been sealed and does the sealer still offer protection from water-based stains.



  1. Make sure surface area is clean, dry and free of waxes and coatings.
  2. Apply a drop of water 1 inch in diameter to the stone surface.
  3. Allow the water to stand on the stone for overnight. Cover with a cup or bowl to avoid evaporation
  4. If surface is unsealed, the water will absorb into the stone and darken the surface (absorption speed will depend on porosity of the stone).
  5.  In the morning you’ll see if the surface is already sealed or if stone is very dense, the water will bead up and stand on the surface. Some Granites are so dense they do not require sealing at all.