Take a picture of your tile and post on a website like Photobucket.com and then link to it here. That might help someone identify what you have.

Here is the image

Ask again to see if there is any luck someone knows about this.

Are those the mildew stains? I googled and found many products deal with mildew stains on marble but not sure this will fix my problem.

It looks like the natural markings on the marble to me.

its part of the stone.