Follow these steps to remove iodine stains from Alabaster or Marble:
- Mix a few drops of ammonia with a cup of 3% hydrogen peroxide.
- Soak a white blotter (about the size of the stain) with the solution and place it over the stain.
- Weight it down with a piece of glass or other heavy object.
- Continue applying the solution until the stain has been bleached out.
- For tougher stains, make a bleach poultice from powdered detergent, bleach, and water.
- Apply this paste to the stain and cover with a damp pad to retard evaporation.
- Leave overnight. Then remove the dried paste, rinse the area with clear water, and dry.