Many stains can be removed in marble, travertine, limestone, terrazzo or porous stone by putting a 30% or 40% peroxide solution on the area. This can be purchased at beauty supply stores. Spread the solution over and past the edges of the stain fairly thick. Cover with plastic or seran wrap and leave over night. Clean up next day. Be sure to wear gloves. A second application may be needed.
Bob – USA Floor Care