Most marble "stains" fall into two categories, and telling them apart is half the battle:
- A true stain — a substance has soaked into the porous stone and discoloured it. The marble is intact; it's just holding colour it shouldn't.
- An etch mark — an acid has chemically eaten the polished surface, leaving a dull or rough patch. The colour is fine; the finish is damaged.
Stains are drawn out chemically. Etch marks are repaired by re-polishing the area. Using a stain treatment on an etch mark does nothing.
Identify the stain first
- Darker than the marble, roughly oily-looking → oil-based (cooking oil, grease, cosmetics, hand cream).
- Brown or orange, often ring-shaped → rust, usually from a metal object left on wet stone.
- Pink, brown or tan blotches → organic (tea, coffee, wine, fruit, leaves, food).
- Blue, black, coloured → ink, paint, dye.
- Whitish, cloudy, or a dull ring → not a stain. Hard-water mineral film or an etch mark.
The poultice method (for genuine stains)
A poultice is an absorbent paste that sits on the stain and pulls the discolouration back out of the stone as it dries. The absorbent base is usually the same (a fine clay or even paper towel); the active ingredient changes with the stain:
- Oil — a solvent or a degreasing agent
- Rust — a rust-specific remover made for stone (never a general acid — it will etch)
- Organic — hydrogen peroxide (for light marble) or an oxidising cleaner
- Ink / dye — a solvent, tested carefully first
Apply a thick layer, cover with cling film taped down, and leave it 24–48 hours to dry fully. Deep or old stains often need two or three applications. Afterwards the area is rinsed, dried, and — if the surrounding floor is polished — the spot is re-polished to blend and then re-sealed so it doesn't re-stain.
What never to do
- Never use vinegar, lemon, or "descaler" on marble. They're acids. They will etch the surface and make things worse.
- Never use bleach or coloured cleaners — they can leave their own stain.
- Never scrub with an abrasive pad or scouring powder — you'll scratch the polish.
- Don't leave metal, plants, or damp cardboard sitting on marble — that's how rust and organic rings start.
When to call a professional
DIY poultices work on fresh, shallow stains. Call a specialist when the stain is old, deep, or large; when you're not sure what caused it; when it's an etch mark (which needs re-polishing, not chemistry); or when there are stains all over the floor — at that point, a full polish is cheaper and gives a uniform result than a dozen spot repairs.