Use a ph neutral cleaner. I'll guarantee you that same tile store will be able to get you one from one of the sealer companies.

So we were dumb enough to put calcutta type tile on our bathroom floors and shower sidewalls. They are now turning yellow like a stodgy old health club. I hear the yellow is from water and possible related Iron in the water. Anyone have experience on how to treat this? Any smart solution to this dumb move of ours. Marble really has few places it should be used in a house....certainly not Kitchen or Baths! LOL Please help!!

I would recommend going to a local tile supply store and they should be able to guide you in the right direction. I have a members only business I work with called ProSource that has a whole showroom of different types of tile. Some tile manufacturers have like 20 different pricing tiers depending on the amount of tile you buy. Being a member allows me to have the larger buying power (theirs), wider selection, and thus a lower price point than if I went to the manufacturer direct and opened an account. They also sell at a wholesale price (My discounted price) or list price. I always pass my wholesale price to the clients - It's the right thing to do! Most of the porcelain tile mimics an actual marble or is very similar so if you find a marble you like then that will give you a better direction to find a manufacturer that can come close. Here is a link to just a google search that shows the wide array of tile that you can get. https://tilebar.com/collection/porcelain-tile/shop-by-look-porcelain/marble-look-porcelain-tile.html Mjammjam - I'm not sure of the type of marble that was listed in the original picture. Save it and go to a local supply store and see if they can find something that looks-alike. Best of luck in your endeavor! And food for thought - Not all tile is made equally. Their is a multitude of different rankings for hardness and durability given the area of application. One is called a PEI (Porcelain Enamel Institute) rating but there are other factors pending what type of tile you go with (Slip resistance, Moh's hardness, abrasion resistance, and frost resistance, breaking strength, water absorption, shade variation, etc.). You can go to The Home Depot and get a good looking floor tile but its PEI rating is like a 2, whereas I can go to a different manufacturer with the same look and gets a much higher PEI rating (around a 4). It cost a bit more but the tile is suited for the application and is more durable in the long run. Well worth the additional $ in my eyes. A good tile salesman will help you find the best tile for your application but it's good to be educated going in! :)

I would have a professional come in and polish and seal the floors. Also, do you have a good fan in the bathroom. I don't wipe down my shower floor or walls but my fan runs automatically based on humidity sensor so my bathroom is dry including shower floors, wall and door. Also my understanding is that marble needs to be sealed once a year. I just finished a remodel which includes marble floors in shower and bath and was told that sealing annually is part of then normal maintenance.