If your quartzite etches, it's probably not quartzite at all, it's dolomitic marble or a calcite-rich stone sold under the quartzite name. True quartzite is mostly silica (Mohs 7) and shouldn't etch. A drop of lemon juice or vinegar that dulls the surface in 60 seconds confirms calcite or dolomite content. MORE® AntiEtch® coating is the lasting fix.

The Mislabeling Problem in the Stone Trade

Quartzite built its reputation on looking like marble but behaving like granite. That reputation is exactly why suppliers stretch the label. A slab that's mostly calcite or dolomite, showing white background with gray veining, sells a lot faster under the quartzite name.

Some of these stones really are quartzite with a bit of dolomite mixed in near the surface. Others are dolomitic marble straight through, quarried right next to real quartzite deposits and nearly identical once polished. Nobody's usually lying outright. Eyeballing a slab in a stone yard isn't the same as testing its mineral makeup in a lab.

What's Actually in Your Countertop

True quartzite starts as sandstone, buried deep enough for heat and pressure to fuse the quartz grains into one dense rock. It runs close to 90 percent silica (SiO2), the same mineral in glass and the biggest component of granite. Silica doesn't react with household acid, so real quartzite shrugs off lemon juice, wine, and vinegar without a mark.

Calcite (CaCO3) is the main ingredient in marble, limestone, and travertine. Dolomite (CaMg(CO3)2) is its close cousin, a bit more acid resistant but still reactive. When a stone marketed as quartzite carries meaningful calcite or dolomite mixed through the quartz, you get something that etches like marble the first time it meets a splash of balsamic vinegar.

If the drop test confirms your countertop reacts to acid, a certified applicator can install MORE® AntiEtch® to stop future etching without changing the stone's finish.

The Mohs Hardness Misconception

Homeowners often get told their stone is quartzite because it's hard, and hardness gets treated as proof it won't etch. It isn't. The Mohs scale measures scratch resistance, nothing more. Quartz sits at 7. Dolomite runs 3.5 to 4, and calcite sits around 3.

A slab with quartz veining through a dolomite-heavy matrix can scratch-test harder than pure marble, which convinces people it's the real thing. But acid doesn't care about scratch resistance. It reacts with the calcium carbonate in dolomite and calcite on contact, dissolving a paper-thin layer of polish no matter how the stone held up to a knife blade.

Confirming It With the Acid Drop Test

You don't need a lab. There's a simple acid drop test, the same one fabricators use to sort stone before it's cut, and it tells you in under two minutes whether your countertop reacts. All you need is white vinegar or fresh lemon juice and a flashlight.

If the test spot dulls, frosts, or leaves a faint ring after 60 seconds, you've got a calcite or dolomite-bearing stone, whatever the fabricator called it. If nothing happens even after 5 minutes, you most likely have true quartzite, and whatever mark sent you looking is probably a water spot or oily residue.

Why Polishing Powder Only Fixes One Spot

Marble and dolomitic stone polishing powder, usually a tin oxide or cerium oxide compound worked in with a buffing pad, can bring shine back to a single etch mark. It removes an ultra-thin layer of stone so the dulled spot levels out with the surrounding polish. For a one-time wine ring, that's a fine fix you can do yourself.

But it doesn't change what the stone is made of. If your countertop is genuinely dolomite or calcite-rich, every new splash of citrus or vinegar dressing puts a fresh etch somewhere else. Polishing out marks every few weeks isn't really an etch problem anymore, it's the stone's chemistry meeting acid, over and over.

The Permanent Fix Is a Coating, Not a Cleaner

Once the drop test confirms your quartzite is acid sensitive, sealing it won't fix the problem. Penetrating sealers fill the pores to slow staining from oil and water, but they don't block an acid reaction. The calcite and dolomite are still sitting right there, exposed to whatever touches the counter.

MORE® AntiEtch® is built for exactly this. It's a professionally applied coating, not a bottle you spray on yourself, put down by a certified applicator who preps the surface and cures the coating correctly. Once installed, acidic liquids sit on top of the coating instead of reacting with the calcite or dolomite underneath.

AntiEtch® doesn't turn your stone into quartz, and it won't make a soft stone scratch-proof. What it does is stop the chemical reaction that causes etching. If your test came back negative and you've got true quartzite, you don't need this at all.