Have you tried Krud Kutter? Read the label I have never used it on marble.
What is the stain from? This conversation might help: http://www.hometalk.com/search?filter=stain+on+marble&search=&zipcode=
Which products have you tried, Jane? Do you know what the stain is from? Also, many times people believe a spot on marble to be a stain when it is really etching, caused by acid contact. Is it rough at all?
The stains are not rough. They have just appeared.........don't know how, if it was something when they were installed a few years ago. I keep a hand towel on the counter when I am using in the morning and I put a coaster on it when I drink my coffee. They are mostly "rings," where we haven't put anything, strange........
I used something from the granite/marble store that they recommended. \
Thx Miriam, i'll check that link.
here is a link with some more common attack plans
I am going to try some of these remedies to see if they work.......