Natural Stone Care in Marin: Marble, Travertine, Limestone, Slate and Granite

“Natural stone” is not one material. The five we see most in Marin homes — marble, travertine, limestone, slate, and granite — react to spills, cleaners, and foot traffic in genuinely different ways, and the care that protects one can damage another.

If you only read one section, read the one on etching versus staining. It is the distinction that decides whether a mark on your stone is a cleaning problem or a restoration problem, and getting it wrong is how people spend money on the wrong fix.

Travertine

Travertine is a form of limestone full of natural voids. Many floors are filled and honed at the factory, and over time those fills pop out, leaving pits that collect soil.

• Its weakness: it is calcite-based, so anything acidic — citrus, wine, vinegar, many bathroom cleaners — etches it on contact.
• What it needs: neutral-pH cleaning, prompt spill wiping, and a sealer that keeps soil out of the open pores.
• What we do: flush the pores with hot water extraction, address failed fills where appropriate, then reseal.

Marble

Marble is the most beautiful and least forgiving stone in the house, and in Marin it is most often a kitchen counter or an entry.

• Its weakness: the same acid sensitivity as travertine, but on a polished surface where every dull spot is visible. A single glass of wine left overnight leaves a mark.
• What it needs: coasters, prompt wiping, and a strict ban on general-purpose cleaners.
• What we do: restore etched surfaces back to a uniform finish, then seal. Most of our Tiburon and Belvedere stone work is exactly this.

Limestone

Limestone is travertine’s denser cousin, and in Marin it shows up as honed floor tile, fireplace surrounds, and the occasional exterior entry. It shares travertine’s chemistry without the open pits.

• Its weakness: calcite-based, so it etches on contact with acid, and because it is usually honed rather than polished, etching reads as a slightly darker, rougher patch rather than a dull spot. It also takes oil and dark liquids into the pores readily.
• What it needs: sealing on a schedule, neutral-pH cleaning, and mats at entries to keep grit from scratching the honed surface.
• What we do: hot water extraction to flush the pores, restoration of etched or scratched areas where the finish allows it, then a penetrating sealer.

Slate

Slate is the outlier: it is not calcite-based, so it does not etch. It has its own problems.

• Its weakness: it flakes and spalls in layers, and in shaded, damp Marin locations it grows an organic film that dulls the surface.
• What it needs: regular removal of that film, and an enhancing or penetrating sealer depending on the look you want.
• What we do: clean out the surface, then seal — and discuss enhancing sealers if you want the wet-look color depth back.

Granite

Granite is the forgiving one. It is not calcite-based, so it does not etch, and it is hard enough to shrug off most of what a kitchen throws at it. That is why it is on so many Marin counters.

• Its weakness: it is still porous. Cooking oil, wine, and coffee left to sit will darken it, and the darker the granite, the longer the stain hides before you notice it. The other failure is a worn sealer that leaves a cloudy, blotchy look around the sink and stove.
• What it needs: a working sealer, checked with the water-drop test once or twice a year, and prompt wiping of oils.
• What we do: clean the pores out, draw out oil stains where they are recent enough to move, and reseal.

Etching versus staining, the one distinction worth learning

If a mark is lighter and duller than the stone around it, it is etching. An acid reacted with the surface and changed its finish. No cleaner will fix it; the finish has to be mechanically restored.

If a mark is darker than the stone around it, it is a stain. Something soaked into the pores and needs to be drawn back out.

People spend a lot of money on the wrong product because these look similar in kitchen lighting. Photograph it in daylight, and if you are unsure, send us the photo.

On calcite stone, both problems are common and both are fixable. Etching is restored by re-honing or re-polishing the surface back to a uniform finish. A stain is drawn out of the pores with a poultice or extraction, depending on what caused it. The one thing neither responds to is scrubbing harder with a stronger product, which is how a small etch becomes a large one.

The care routine that works for all three

1. A neutral-pH cleaner formulated for stone. Nothing else.
2. Wipe spills promptly, especially oils, wine, and citrus.
3. Mats at entries to trap grit before it reaches the stone.
4. Professional cleaning and resealing every two to three years, and toward the shorter end in coastal and damp locations. If you are not sure whether your sealer is still working, the water-drop test takes five minutes.

More detail on the surfaces we handle and how sealing works is on our stone, tile and grout page, or ask us for a free estimate.