Limestone, honed back and sealed.
Limestone is the same chemistry as marble without the heat and pressure, so it etches the same way and stains more readily. Most of it is finished honed rather than polished, and most of what goes wrong with it comes back with a hone and a sealer.
Limestone is calcium carbonate laid down on ancient sea floors, and marble is what limestone becomes under enough heat and pressure. That shared chemistry is the first thing to know about it: it etches on contact with acid exactly as marble does, so lemon, wine and most bathroom cleaners leave the same dull marks. What differs is the structure. Limestone is softer, more uniform, and generally more porous, which is why it is usually sold honed rather than polished and why it takes a stain faster than a polished marble would.
The damage is familiar and the causes are the same. Etching in a kitchen or around a basin. Staining where oil or wine has had time to soak in. Traffic lanes on a floor going matte before the edges do. Fine scratching from grit underfoot. Some limestones also carry small natural voids and fossil pockets that open up as the surface wears, and a dense one can lose a gloss it was never really able to hold.
The work is honing. The etched, worn top is taken back to sound stone with diamond abrasives, open voids are filled with a matched compound, and the surface is brought to an even honed finish across the whole area rather than spot-treated, so there is no halo where the repair was. Where the stone is dense enough to hold it, a polish can follow. A penetrating sealer finishes the job, and on limestone that step matters more than on almost any other stone because of how quickly it drinks.
Where the limit sits: not every limestone will take a polish, and a soft, open one that is forced to a gloss loses it within months. The honest finish for those is honed, and we will say so before starting. Fossil pockets and voids are the stone, not damage, and filling every one of them makes the surface read as artificial. Deep oil staining in a very open limestone is often reduced rather than removed.
Questions about limestone.
Can etched marble be restored, or does it need replacing?
Etched marble can be restored in place, and replacement is almost never the right answer. Etching is a thin layer of the polished surface dissolved by acid. It is not a stain and it does not go deep. The mark is honed off with diamond abrasives and the area is re-polished to match the rest of the top. On a benchtop that is usually a couple of hours of work, done on the bench with the kitchen protected. Deep etching that has left a visible dip takes more honing and blends less perfectly, and that is exactly the sort of case we cut a test patch for before committing. Replacing a benchtop means a new slab, templating, fabrication, removal, plumbing and a splashback, and weeks without a kitchen. Restoring it is a fraction of that.
What is the difference between honed and polished, and which should I choose?
Polished is the mirror finish; honed is matte. Both are produced by the same abrasive sequence, stopped at different points. Polished shows the depth and colour of the stone at its best and reflects light, and it also shows etching and wear more readily. Honed hides small marks, gives a softer look, and is the usual choice for floors in busy houses and for travertine. Neither is more durable than the other in the stone itself; the difference is in how visible wear is. If you had polished and are tired of seeing every mark, honing is an option. If you had honed and want the depth back, polishing is the same work in the other direction. There is a middle setting as well. Stopping the sequence short of a full polish gives a low sheen that lifts the colour without becoming a mirror, which suits a kitchen where reflections of downlights are the thing people find tiring.
How often should marble be sealed?
It depends on the surface and what it takes. A kitchen benchtop or a shower, which see acid, oil and water daily, are usually resealed every twelve months. A floor or a table in a lower-traffic room goes two years or more. The honest test is the water bead: a few drops left on the stone for ten minutes should sit up. If they soak in and darken the stone, the sealer has worn and it is time. We add every surface we seal to a reminder list and message you when yours is due, so you do not have to remember. A sealer is not a coating sitting on top. A penetrating sealer soaks into the stone and slows how fast liquids get in, which buys time to wipe a spill before it becomes a stain. It does not stop etching, because acid attacks the surface of the marble itself rather than soaking into it, and nothing short of changing the stone prevents that.
Other materials