I have a veined white marble floor that has discolored due to water wicking through the concrete slab from a water-filled structure directly below the 4" slab that supports the marble floor. On the part of the floor above the water-filled subgrade structure, the white marble is discolored a yellow-gold. The part sitting directly on dry subsoil is still white. The yellow gold color is not a bad shade, but it now means one part of floor is a different color than the rest of the floor; All of the marble matched perfectly when laid in 1984.
The original veining is grey, greenish gray and a little yellow-gold, but the overall color is white.l
Does anyone know of a treatment that will remove this discoloration? Believe me, this is not a surface stain. I've gone over the surface with all kinds of abrasives, including some very dangerous ones, such as sandpaper, muriatic acid, etc.