QUESTIONWe have a marble countertop that has white stains from lemon juice. How can we remove the powdery white stains and restore the marble?
ANSWERANSWER - Marble is made up mostly of calcium carbonate, which is a material that is sensitive to acid. Lemon juice is acidic with a pH around 2; neutral is a pH of 7. So it is very acidic. The acidic lemon juice bleaches the marble leaving white spots, and it also etches the marble leaving a textured finish. The etching chemically alters the finish of the marble.
It is possible to repair the marble by re-grinding the marble to remove the bleached area and re-polishing the marble to its original finish.
Best bet is to hire a professional stone restoration company who has a lot of experience to help determine how to repair the marble countertop. Otherwise you could go online and look for marble refinishing kits that are sold by companies who make cleaners for stone. I don't know how effective the kits are, but it might be worth a try. Go to the CTaSC website to the Cleaners and Sealers Resource section to see a list of companies who provide cleaners: Cleaners and Sealers.