Rust can be a common problem especially on many white stones. Many stones naturally have iron as a major component. With iron, you guessed it, comes rust! But can it be fix?
The answer is maybe. In the photos below notice the rust spots on the marble. The two stains are from a different source. One stone had a metal item that caused a rust ring. The other stone close to the toilet was caused from some minor water damage.
However the treatment soaks into the stone and can keep working for some time. After retuning over a month later for a different project in the home we were thrilled to see that the rust was finally gone.