It is 0700 and the master bathroom Calacatta marble vanity has a lemon wedge sitting on it from the owner nightcap. Underneath it is a dull white patch. Beside it, the antiqued mirror is fogged and the polished bronze basin trim is fingerprinted. Three surfaces, three failure modes, and only one of them is actually dirt.
Natural stone
Marble, onyx and travertine are calcium carbonate. Acid dissolves them. That dull patch is not a stain — it is an etch, a chemical burn where the polish is gone.
| Stone | Character | Risk | Care |
|---|---|---|---|
| Marble | Polished, veined | Etching by acid; staining through pores | pH-neutral stone cleaner, soft cloth, dry buff |
| Onyx | Translucent, often backlit, fragile | Etching, cracking, heat from backlighting | Dry or barely damp; never a soaking cloth |
| Travertine | Porous, filled voids | Fillers pop; staining | pH-neutral cleaner; keep water out of open pores |
| Granite | Hard, acid-tolerant | Sealer loss | Neutral cleaner; still no acid habits |
Acids to keep away from stone: citrus, wine, vinegar, tomato, coffee, descaler, most limescale and toilet products, and many "bathroom sprays". A spray-and-wipe bottle in the wrong hand ruins a vanity top in a week.
- Seal: impregnating sealers sit below the surface and buy you time against staining. They do not stop etching. Water beading tells you the seal is live; a dark patch that fades tells you it has gone.
- Poulticing: an organic stain (wine, coffee, oil) that is in the stone is drawn out with a poultice — an absorbent powder mixed with the correct chemical, spread 5-10mm thick, covered, taped, left to dry fully (typically 24-48 hours), then removed. It may need repeating. Etch marks are not lifted by poultice; they need re-polishing by a specialist.
Mirrored and antiqued glass
- Plain mirror: spray the cloth, not the glass — cleaner running to the edge attacks the silvering and causes black edge creep.
- Antiqued and distressed mirror has the "damage" designed in; its rear coating is delicate and often unsealed. Dry microfibre or a lightly damped cloth only. Never ammonia, never a wet flood.
- Do not use blue window cleaner anywhere near lacquered timber frames.
Metals
| Metal | Care | Watch out |
|---|---|---|
| Polished stainless | Neutral cleaner, dry with the grain | Chloride pitting from salt and bleach; tea staining |
| Chrome | Damp cloth, dry buff | Abrasives cut through the plating |
| Brass / bronze (lacquered) | Dust and damp-wipe only | Metal polish strips the lacquer and starts uneven tarnishing |
| Brass / bronze (unlacquered) | Approved polish, sparing, per SOP | Over-polishing wears detail; some owners want the patina |
| Gold plate | Soft dry cloth | Micron-thin — any polish or abrasive removes it |
Know before you polish whether a metal is lacquered or living. If nobody knows, dust it and ask.
Onboard Notes
- Coasters, trays and mats under everything acidic. Brief the chef and the deck team too — a wet glass on marble is a shared problem.
- Blot spills on stone immediately, then rinse with clean water and dry. Speed is the whole game.
- Salt air plus stainless plus a warm deck equals tea staining. Fresh-water rinse and dry beats any chemical.
- Never mix products or improvise. A bathroom descaler used once on marble is a five-figure re-polish.