We had Emperador Light marble installed on our bathroom countertop, shower threshold, shower sill, and shower bench. I didn't notice it at first but after only 2 weeks of using the shower the bench has 2 fairly large white spots that are rough to the touch. I've still been trying to figure out what to clean with that is gentle so we have not used any cleaners at all in the shower - only water. I used Olay bar soap for about a week and after I noticed the spots, I switched to a body wash that has nothing but natural ingredients. I'm not exactly sure what my shampoo and conditioner have in them but those 3 things are the only things besides water that have been on the bench.

The spots are almost directly under where the shower head and hand held spray, but they both spray past the bench not onto it. The bench does seem to have a good 1/2 inch of standing water that runs off or evaporates within about an hour or so of showering. The threshold has standing water on it after a shower for most of the day but it has not developed any white spots.

Sorry for the long post but I'm hoping someone will have some ideas. Contractor is on vacation for 2 more weeks and I'm anxious to get an idea of what it could be! Thanks!!

Here is a link that might be useful: Photos of white spots on marble shower bench