QUESTIONI recently had granite installed and after a few days, I noticed these brown spots appearing in a few spots. I tried using several cleaners and nothing is working and am trying to find something to remove it. The installer said that because it's a natural stone, it may have oxidized and out of his control. I'm not sure why it would do that but tried that Rust Ex and it didn't do anything and found my way to your site and figured to ask. Any insight and guidance is very much appreciated.
ANSWERANSWER - Determining what is causing a stain or how to remove it, depends on whether this is a granite countertop or a granite floor tile or a granite wall tile in a shower or what... Also is it inside or outside and what are the climatic conditions, and what are the underlying conditions of where the stone is installed. Also depending on whether the stone has a polished or honed or flamed surface can make a difference.
Natural stone consists of a blend of different minerals and often contain iron oxides that when subjected to moisture can cause a rust stain. Sometimes a metal object touching the stone can cause a rust stain. Surface rust stains are generally easier to remove, but if they are deep stains they can be hard or impossible to remove completely. I would try one of the stain removers sold by stone suppliers to see if it will work. Always be careful and test what you do before going to far with it or you could have bigger problems. You can consider hiring a professional stone restoration company to have them try to remove the stain.
If you seal the surface of the stone with a stone penetrating sealer it can help keep surface moisture away.