Category: Marble guides

To clean marble, use warm water and a neutral detergent with a pH between 7 and 10: stone soap or a mild washing-up liquid. Apply with a microfibre cloth, rinse with clean water, dry immediately. Avoid vinegar, bicarbonate, descaler, bleach and scouring powders.

This page deals with one subject only: the method. Which products to use, how, and how often. Treating an established stain and the routine specific to each surface are covered on two separate pages, linked below. To choose a material, see our marble tiles.

Key points

• Day to day: warm water and a neutral detergent with pH 7 to 10. The Natural Stone Institute cites “a neutral cleaner, stone soap, or a mild dishwashing liquid”.
• Vinegar is the reagent geologists use to identify a limestone: poured on the rock, it releases bubbles of carbon dioxide (University of Waterloo).
• Bicarbonate does not attack the stone chemically; it scratches it: calcite sits at 3 on the Mohs scale and scratches with a knife blade.
• The rule to remember: vinegar dissolves the stone, bicarbonate scratches it, and neither cleans a limestone.
• An area that has become matt is not a stain but a loss of material, the dulling of the ICOMOS-ISCS glossary. It cannot be cleaned; it is repolished.

The method, in four steps

Four steps cover routine cleaning, whatever the surface. The order matters as much as the products.

1. Dust dry. A dry microfibre cloth, or a soft broom on floors, removes abrasive particles. Going straight to water just drags them across the surface.
2. Wash with warm water and a neutral detergent. Soft cloth or sponge, without pressing, and without soaking the surface.
3. Rinse with clean water. Poorly rinsed detergent residue leaves a dull film, often mistaken for deterioration of the stone.
4. Dry immediately with a second clean, dry cloth. Water left to dry on its own deposits its minerals and leaves rings.

To be avoided here: metal utensils, which producers’ data sheets rule out because of the risk of scratching, and the green side of sponges. If the surface remains matt after drying, the problem is no longer cleanliness.

Which products are allowed

Producers’ instructions come down to a range: detergents with a pH between 7 and 10, never more. The Natural Stone Institute puts it in kitchen language: “a neutral cleaner, stone soap, or a mild dishwashing liquid and warm water”.

A neutral pH is the value 7 on the pH scale, that of pure water: below it the solution is acidic, above it alkaline. Data sheets tolerate up to 10, slightly alkaline, never a step towards acid.

The second criterion appears on no label, and it is mechanical: the product must be free of solid particles. Scouring powders and creams “contain abrasives that may scratch some stones”, writes the Natural Stone Institute. A cleaner can therefore be neutral and still damage the surface.

What you must not do, and why

The two most widespread recipes on the French-speaking web are the two never to bring near marble. They do not pose the same problem, and that distinction lets you judge any other product.

White vinegar is for identifying a limestone, not cleaning it

Vinegar is a field reagent. To recognise a limestone, the Earth Sciences Museum at theUniversity of Waterloo describes a simple test. A dilute acid is poured on cold, “10% hydrochloric or sulphuric acid, or vinegar”, and the rock gives off bubbles of carbon dioxide. The effervescence is the signature of carbonate.

Calcite is the calcium carbonate (CaCO₃) of which a marble is overwhelmingly composed. The reaction in the test therefore happens in exactly the same way on a worktop: the calcite dissolves, and the bubbles are stone leaving. The US Geological Survey describes the same mechanism on buildings, where acids in rain dissolve calcite and erase carved details.

Lemon works by the same mechanism: the Natural Stone Institute writes that products containing “lemon, vinegar or other acids may dull or etch calcareous stones”. There is in fact no pH threshold below which the attack would start; only the speed varies with acidity.

The advice is so entrenched that professional documents repeat it. The 2025 data sheet of a Spanish producer requires, on the same page, using only pH 7 to 10 and ruling out descalers, then recommends “diluted vinegar” against oil stains. The instruction and its opposite, two paragraphs apart.

Bicarbonate of soda does not dissolve marble; it scratches it

Sodium bicarbonate is alkaline: it does not attack calcium carbonate chemically. The problem is abrasion. The university source that describes the vinegar test places calcite at 3 on the Mohs scale and states that it “is easily scratched with a knife blade”. A powder paste rubbed on a polished surface works against a soft mineral.

These micro-scratches are not visible head-on but in raking light, as a matt halo: precisely the look you were trying to correct by rubbing. On a porous stone, poorly rinsed salt can also migrate, then recrystallise on the surface as a white powdery haze.

Products to avoid

• Vinegar, lemon juice, citric acid : dissolution of calcite.
• Descalers and limescale removers : ruled out by producers’ data sheets, since they are designed to dissolve carbonate.
• Bleach and ammonia : ruled out by the same data sheets, which allow only the pH 7 to 10 window.
• Scouring powders and creams, clay stone, abrasive sponges, brushes and metal utensils : abrasion of a surface at Mohs 3.
• Commercial rust stain removers : the most serious case. The Natural Stone Institute notes that they “contain traces of hydrofluoric acid”. This product has no business near marble.

Unsure about a bottle? Two questions are enough. Is it acidic, with a pH below 7? Does it contain solid particles? A single yes is enough to rule it out.

White marble, very dirty marble: what changes

Nothing changes in the product; everything changes in the repetition. Faced with a heavily soiled surface, the right answer is not a stronger cleaner but the same neutral cleaner applied in several successive passes, with a cloth rinsed or changed often, and drying between passes. You progress by degrees, never by escalation.

Two points for white marble. It does not need a special product, but it shows what dark shades hide: the slightest detergent residue, the slightest ring. And a new coloured microfibre cloth can transfer dye onto a light, porous stone.

A technical point justifies this caution. On the same open porosity test, NF EN 1936, the marbles and limestones on the market range from about 0.2% to 17% depending on the variety. The same method therefore does not behave in the same way on two different stones. There is also a standardised test for resistance to accidental staining, NF EN 16301, which none of the data sheets consulted declares. Ask for it.

One last limitation: hard limescale deposits, which the ICOMOS glossary calls encrustation, adhere strongly, and removing them “may be accompanied by detachment of stone”. That case is a matter of remedial treatment, not routine care.

Cleaning does not fix a matt area

If an area has become matt, no cleaning will fix it, because there is nothing to remove: the material has gone. This is the most useful distinction in this article, and it is standardised.

Dulling is the French term that the ICOMOS-ISCS illustrated glossary of stone deterioration patterns uses for the increase in roughness of an originally polished surface. The glossary specifies that this increase can be “immediate, as with aggressive cleaning”, and that loss of polish produces an increase in lightness, particularly visible on dark marbles.

This vocabulary settles a common confusion. Dulling belongs to the family of losses of material, a stain to that of chromatic alterations: two distinct families, two distinct responses. A stain is cleaned, dulling is repolished, and producers point out that a surface can always be restored by repolishing.

Rubbing harder therefore only widens the matt area. To identify and treat a specific mark, coffee, wine, oil, rust, see our stain removal methods for marble, stain by stain.

How often to wash a marble surface

The frequency is set by the surface’s actual exposure, not by a calendar. Three rhythms coexist, and the first matters most.

• Immediately : any spilt liquid, acidic liquids first. The dissolution of calcite has no grace period.
• Regularly, dry : dusting, which removes particles before they act as an abrasive. The most cost-effective and most neglected step.
• Periodically, with soapy water : a full wash, whose frequency depends on traffic and use.

A water-repellent or impregnating sealer replaces none of these three rhythms: it slows the penetration of liquids, without doing away with wiping or with sensitivity to acids. The precise rhythm depends on the surface, and a hall floor, a table, a worktop and an outdoor slab do not call for the same frequency: that is the subject of our marble care guide, surface by surface.

Frequently asked questions

Can marble be cleaned with white vinegar?

No, never, not even diluted. Vinegar is one of the reagents the University of Waterloo cites for identifying a limestone: poured on the rock, it releases bubbles of carbon dioxide, because the calcite dissolves. On a polished surface, the same reaction leaves a permanent matt area.

Is bicarbonate of soda suitable for marble?

No. It is alkaline and so does not attack the stone chemically, unlike vinegar. The risk is mechanical: it is a powder, and calcite sits at Mohs 3, a mineral that scratches with a knife blade. A paste rubbed on a polished surface leaves a halo of micro-scratches.

How do you clean very dirty marble?

With the same product, but several times. Dust dry, then repeat the wash with warm soapy water, changing the cloth often, rinsing and drying between passes. Increasing the strength of the product is the one thing not to do: that is how reversible soiling becomes permanent dulling.

How do you clean white marble without dulling it?

With the general method, taking care over the last two steps. On a light stone, dullness almost always comes from poorly rinsed detergent residue or water left to dry on its own, not from dirt. Rinse, dry within a minute, and check that your microfibre cloth does not transfer dye.

Are black soap, clay stone and whiting suitable?

They share the same blind spot. Clay stone and whiting are powders, and therefore abrasives on a mineral at Mohs 3. Black soap is an alkaline soap, often wrongly presented as neutral: none of the technical sources consulted publishes its pH value. In the absence of a verifiable value, a mild washing-up liquid remains the documented choice.

In summary

It all comes down to a neutral product, rinsing and drying. The rest is about not making things worse: no acid, no powder, no metal, no rubbing on an area that is already matt. To decide on a variety, a finish or a thickness, contact us.

On standardised tests, granite clearly outperforms marble on only four criteria: compression, abrasion, frost resistance and acid resistance. For density, open porosity and flexural strength, the ranges overlap. Choosing between marble and granite therefore comes down to those four points.

This comparison is less clear-cut than most you will read, and that is deliberate. It keeps only values published with their test standard: six technical documents for granite, including three data sheets from CTMNC’s COFRAC-accredited laboratory, and five producer data sheets for marble. Missing data are flagged as such, never filled in. See also our marble worktops.

Key points

• Only four criteria clearly separate the two stones: compression (140 to 219 MPa against 96 to 145 MPa, NF EN 1926), abrasion, frost resistance and behaviour with acids.
• Granite is not denser than marble: 2,650 to 2,710 kg/m³ against 2,660 to 2,720, on the same NF EN 1936 test.
• “Hardness 6 to 7 Mohs” for a granite is a category error: the scale is defined for minerals, and a granite contains at least three.
• The only clear chemical difference: the calcite in marble dissolves in a weak acid, the silicates in granite resist it. That is what the USGS writes.
• No temperature limit in degrees is published for either family. And a mechanical value quoted without its test standard cannot be used.

Four criteria genuinely separate the two stones

On identical tests, granite’s advantage is clear and consistent on four lines only: compression, abrasion wear, frost resistance and acids. Elsewhere the ranges overlap, sometimes completely. That is why the “test standard” column is there: without it, two figures cannot be compared.

The granite values come from CTMNC Lithoscope for three identified French stones, from the Association Granit et Pierres du Sidobre and from Grupinex. For marble, five producer data sheets, including a “Vratza marble” made of 91.5% calcite: it is this one that widens the porosity range so much. All rights reserved to CTMNC, www.ctmnc.fr.

A value without its test standard means nothing

Two figures can only be compared if they come from the same test, and most online comparisons break this rule. The most common case: they set a water absorption measured under NF EN 13755 for marble against an open porosity measured under NF EN 1936 for granite. Two quantities, two protocols. The comparison makes no sense, and it always comes out the same way.

The most telling demonstration comes from a single stone. Lanhélin granite, in Ille-et-Vilaine, is declared at 210 MPa in compression under NF EN 1926, the paving standard, and at 221.5 MPa under NF EN 772-1, the masonry standard. Same quarry, same block, two numbers. So ask for the data sheet of your batch with its standards, not that of the stone family: granite compression varies from 80 to 270 MPa depending on the producer.

A granite’s hardness cannot be reduced to one figure

“Granite has a hardness of 6 to 7 on the Mohs scale” is a category error, not an approximation. TheMohs scale is defined for minerals: the protocol consists of scratching the smooth surface of a mineral to identify it. A granite is not a mineral; it is a rock that combines several.

The Association Granit et Pierres du Sidobre describes its own stone as an assemblage of feldspar, quartz crystals and small crystals of black mica and biotite. Quartz is grade 7, feldspar grade 6, and micas are markedly softer than both. Scratching a granite therefore means scratching whichever mineral the point meets. Marble, by contrast, can be read as a single figure because it has only one key mineral, calcite, at grade 3.

The scale is also ordinal. The University of Auckland describes it as arbitrary and non-linear, the intervals between grades not necessarily being equal: writing that a granite is “twice as hard” as a marble on the basis of 6 against 3 therefore makes no sense. There is in fact no longer a European standard for the hardness of natural stone, NF EN 14205 having been withdrawn in September 2013. The usable comparison is wear under NF EN 14157: 16.5 to 22.5 mm for granites, 21.5 to 22 mm for marbles.

Acids: the only clear chemical difference

Marble and granite do not react in the same chemical register, and that is the decisive difference for a worktop. TheU.S. Geological Survey puts it in two sentences. The first: “granite is composed mainly of silicate minerals, such as feldspar and quartz, which are resistant to acid attack”. The second: “limestone and marble are composed mainly of calcite, calcium carbonate, which dissolves readily in a weak acid”.

In kitchen terms: a forgotten slice of lemon, a dash of vinegar or the dregs of a glass of wine mark a marble and not a granite. The mark is not a stain but acid etching, a very superficial loss of material that dulls the surface and makes it look lighter. It is corrected by repolishing: the drawback is real, but reversible.

A nuance is needed, which the market systematically skips: the sources write “resistant”, never “impervious”. Granite weathers too, through slow hydrolysis of its feldspars into clay minerals, on a geological timescale. That is not what lemon juice does to a worktop, but nobody should write that granite is chemically inert either.

Heat: the most widespread argument, and the hardest to source

“Granite resists heat, marble does not” is supported by no serious source, either way. No maximum temperature in degrees is published by a technical body for either family. The only pages that put forward figures, from 176 °C to 450 °C depending on the article, are commercial, and they do not agree with one another.

What is solid is worth more than an invented figure. There is a European test of accelerated ageing by thermal shock, NF EN 14066, and a standard dedicated to marble alone for its behaviour under thermal and moisture cycles, NF EN 16306; granite has no equivalent. On the two data sheets consulted that declare the NF EN 14066 test, the marbles tested lose no mass, one reporting zero change after twenty cycles. Use a trivet on both stones, and treat the question as open.

Drawbacks of marble and granite

What are the drawbacks of marble?

Marble scratches and marks more easily than most worktop stones. Its key mineral, calcite, is at grade 3 on the Mohs scale and dissolves in a weak acid: vinegar, lemon, wine. Its porosity varies from 0.2% to 17% across the data sheets consulted.

Three practical consequences follow. Porosity is a property of the batch, not of the family, so susceptibility to staining must be asked about batch by batch. Frost resistance is frequently not declared by marble producers, which makes any outdoor use in a frost zone risky. And with a polished finish on a wet floor, a marble measured under NF EN 14231 drops to 10 to 15 SRV, enough to rule out polished finishes for a shower floor.

What are the drawbacks of granite?

Granite is neither scratch-proof nor waterproof. It is a multi-mineral rock, including micas markedly softer than quartz, and its open porosity remains between 0.2 and 0.5%. Its mechanical variability is wide, from 80 to 270 MPa in compression, and its speckled grey colouring offers little variation.

The Sidobre association itself acknowledges that its granites range from light grey to dark grey: that is the most concrete limitation compared with a veined marble. Be wary, too, of trade phrases. “Scratch-proof”, “harder than metal” or “200-year lifespan” do appear in professional documents, but outside their standardised test tables. They are statements, not measurements.

Does a granite worktop emit radon?

It is “extremely unlikely” that a granite worktop raises the annual radiation dose above natural background. That is the position of theUS Environmental Protection Agency, on a page updated on 12 January 2026.

The same agency adds that radon from the ground beneath homes is a more common problem and a “much greater” health risk than that from granite building materials. It recommends testing for radon in every home, with or without a granite worktop. The wording is “extremely unlikely”, not “zero risk”: it is a concern to keep in proportion, not to dismiss.

What makes the price of a worktop vary

No prices are given here: no public, verifiable source documents French price ranges for 2026. The figures in circulation come from quote aggregators that do not agree with one another. The six parameters that make the difference on a quote can, however, be identified, and they weigh more heavily than the choice of stone family.

• The variety and its availability: two grey granites are not worth the same depending on the quarry and the rarity of the batch.
• Thickness, in millimetres: 20 mm and 30 mm require neither the same material nor the same reinforcement.
• The finish : polished, honed, bush-hammered or flamed, each represents a different number of passes.
• Format and cut-outs : length of the largest piece, joints, sink, hob.
• Edge treatment : a polished square edge and a moulded edge do not take the same workshop time.
• The scope : supply only, supply and shaping, or a full service including installation.

One last pointer: the market prices by square metre of finished worktop, not by linear metre of cabinet. A quote expressed per linear metre hides the thickness, depth and edges, so it cannot be compared with another. Our marble tiles give a first point of reference on materials.

Care: what each stone requires

Both stones are cleaned with a neutral detergent, and neither tolerates vinegar. The producers’ instruction is a pH between 7 and 10, excluding bleach, ammonia and descalers. Scouring powders should also be avoided: they contain abrasives, and calcite scratches with a knife blade.

The difference lies in tolerance of error, not in method. On a marble, a spilt acidic liquid must be wiped up immediately, because the reaction starts straight away; on a granite, it leaves time to act. In both cases, a water-repellent or impregnating sealer reduces absorption without making the stone waterproof, and is renewed according to the worktop’s actual exposure, not to a fixed calendar. One last useful habit: resistance to accidental staining is the subject of a standardised test, NF EN 16301, which none of the data sheets consulted declares. Ask for it.

The choice does not stop at the rock family: two marbles can have porosities a factor of ten apart. To find out what a trade name covers, see what the trade name does not tell you about the rock.

Two extensions of this comparison deserve a page of their own. On the marble side, the real limits of a worktop — scratches, acid etching, variable porosity — are set out without softening them. Outdoors, where frost and run-off change the ranking, see marble or granite for terraces and paving.

Frequently asked questions

What is the difference between marble and granite?

It is mineralogical. Marble is a carbonate rock made of calcite, a mineral that dissolves in a weak acid. Granite is a fully crystallised igneous rock made of silicates, mainly quartz and feldspar, which resist acid attack. The rest, density, porosity, flexural strength, depends on the specific batch and not on the family.

Is marble suitable for a kitchen worktop?

Yes, provided you accept acid marks. A marble kitchen worktop will hold up mechanically, but spilt citrus or vinegar will leave a dulled area until it is repolished. If that patina bothers you, keep marble for the splashback, a display island or the bathroom, and use granite for the preparation area.

Does a granite worktop need a water-repellent treatment?

Yes, it is useful. Granite is not waterproof: its open porosity lies between 0.2 and 0.5% under NF EN 1936, and one family data sheet declares up to 0.7% water absorption. An impregnating sealer slows the penetration of grease and staining liquids, without eliminating porosity or replacing wiping.

How much does a marble or granite worktop cost?

No public French reference makes it possible to give a reliable range, and the figures in circulation come from quote aggregators that diverge. To compare two offers, bring them to the same scope: same variety, same thickness in millimetres, same finish, same number of cut-outs, same edge treatment, and installation included or not on both sides.

In summary

Granite wins on four measured criteria, and marble really loses on only one point that matters in the kitchen: acids. Everything else is decided at batch level and can be read on a data sheet with its test standards. Two documents are therefore enough to decide: the batch data sheet and the chosen finish. To look at materials and decide on a thickness for your project, contact us.

The Carrara marble quarries work the Marmi formation in the Apuan Alps, Tuscany. The original rock is a Lower Lias platform limestone, transformed into marble by greenschist-facies metamorphism with a peak temperature between 350 and 450 °C.

This page starts from geology rather than quarry imagery, because geology is what explains the differences between Bianco Carrara, Statuario and Calacatta. It also gives the production figures actually published by the municipality of Carrara, which contradict several ratios widely repeated online. For choosing a material, see our marble tiles.

Key points

• The protolith of Carrara marble is a Lower Lias carbonate platform limestone, dated to the Hettangian, about 210 to 200 million years ago.
• Bianco Carrara, Statuario and Calacatta are distinguished not by taste but by the structure of the rock: Calacatta is a breccia, the other two are not.
• The Apuan Alps are a UNESCO Global Geopark, with more than 250 geosites and about 200 recorded mineral species.
• The municipality of Carrara extracted 656,000 tonnes of marble blocks in 2023, from about 70 active quarries. That is a historic low.
• Academics have identified only seven geological varieties in one valley of the basin, for more than fifty local names. Trade nomenclature is not a classification.

Where the Carrara basin lies

The quarries are in the Apuan Alps, a Tuscan massif shared between the provinces of Massa-Carrara and Lucca. The marble belongs to the Apuan Alps metamorphic complex, and more precisely to the Marmi formation. The Carrara basin in the strict sense is therefore only part of a wider area that extends towards Versilia and Garfagnana.

This geographical distinction has a direct commercial consequence. Calacatta Vagli, for example, is quarried in Garfagnana, at Vagli, not in the Carrara basin. A trade name containing “Calacatta” therefore does not guarantee a Carrara origin.

The massif also holds the status ofUNESCO Global Geopark. UNESCO lists more than 250 geosites and about 200 mineral species there, 18 of which were discovered on site. The territory is thus both an industrial district and a recognised geological heritage site.

The origin of Carrara marble: a Lias limestone

Carrara marble is a recrystallised limestone, not a rock born as marble. A protolith is the starting rock from which a metamorphic rock derives. Here, the protolith is a massive Lower Lias carbonate platform limestone, attributed to the Hettangian, about 210 to 200 million years ago.

Metamorphism is the transformation of a rock in the solid state under the effect of temperature and pressure. In the Apuan Alps it took place in the greenschist facies, with a peak temperature estimated between 350 and 450 °C. The calcite of the limestone recrystallised into a mosaic of interlocking crystals, which erased the original fossils and sedimentary structures.

The present arrangement is more recent than the metamorphism itself. It results from multi-phase deformation linked to the building of the Apennine chain in the Tertiary, between about 28 and 12 million years ago. These folds and faults now determine the orientation of the beds and the fracturing, and therefore the size of extractable blocks.

There is a practical consequence for the buyer. The dominant mineral remains calcite, at 3 on the Mohs scale. A Statuario and a Calacatta therefore have the same mineralogical hardness: the price difference between them reflects no difference in resistance.

Bianco Carrara, Statuario, Calacatta: three rock structures

The difference between these three families is petrographic, not aesthetic. The definitions below are those of Piero Primavori, who nominated Carrara marble as a Global Heritage Stone Resource with the Geological Society of London.

The bold, contrasting veining of a Calacatta is therefore not a vein in the sense of a Bianco Carrara. It is the matrix that separates the fragments of the breccia. Primavori also notes that this variety is rare, and heavily copied by makers of engineered stone. To choose between the two families for a project, see the differences between Calacatta and Carrara.

The Apuan basin produces many other varieties: Paonazzo, Marmo Venato, Bardiglio, Marmo Nuvolato, Arabescato, Zebrino, Cremo, Seravezza breccias and cipollini. Yet a study published in Geoheritage in 2020 examined nine basins in the Frigido valley. Its authors identified only seven distinct commercial varieties there, corresponding to more than fifty local names.

This is the key point of the whole Carrara nomenclature. Seven geological types, more than fifty names: trade names do not form a taxonomy, and two different names can refer to the same rock.

What actually comes out of the Carrara quarries

The municipality of Carrara extracted 656,000 tonnes of marble blocks in 2023, described by the local press as a historic low, from about 70 active quarries. This figure shows the real order of magnitude of a basin often presented as inexhaustible.

The long series is even more telling. A Legambiente Carrara report, based on records of the Comune di Carrara, totals 16,507,978 tonnes of blocks between 2005 and 2023, an average of 868,841 tonnes a year. The same work states that across 76 quarries, between 2005 and 2022, more than 68 million tonnes of material were extracted, only 22.8% of it as blocks.

In other words, the slab is not the main product of a Carrara quarry. Most of the volume leaves as scaglia, the fragmented rock used for aggregates and mineral fillers. Before the third standing advisory committee on marble policy, a report presented in 2026 put 2025 at just over 600,000 tonnes of blocks, against 873,000 tonnes of white scaglia and 1.2 million tonnes of dark scaglia.

A very widespread ratio must go here, because it does not stand up to scrutiny. It is often said that “Carrara accounts for 95% of what comes out of Italian quarries and Calacatta 5%”. This sentence comes from a commercial page that cites no source. It adds a territory to a variety, and applies a basin ratio to the whole of Italian stone production, granites and travertines included.

No public breakdown of Carrara production by variety could be found. The Osservatorio del Marmo has published an annual report since December 2024, but without a breakdown by trade name. Any share of production attributed to Calacatta or Statuario should therefore be regarded as unverifiable.

A “Marmo di Carrara” mark in the making

In 2026 there is no protected designation for Carrara marble, nor any specification defining a “Calacatta Gold” or a “Calacatta Michelangelo”. These names are names of quarries, beds, blocks or companies.

A process has, however, been launched. On 4 August 2026, the partners of the Osservatorio del Marmo signed a three-year agreement for 2026–2028 that formally commits to creating a “Marmo di Carrara” mark certifying quality and origin across the whole supply chain. It brings together the Comune di Carrara, the Camera di Commercio Toscana Nord-Ovest and, as a new member, the Agenzia delle Dogane e dei Monopoli.

Two limitations should be stated straight away. The mark would cover Carrara marble, not commercial sub-names. And to date, the only quarry-to-name attributions actually documented in the Calacatta family are Crestola, linked to the quarry of the same name in the Torano basin, Franchi, linked to the Bettogli quarries, and Macchia Oro, cited by Primavori.

In the meantime, only one document settles the matter: the supplier’s data sheet. The NF EN 12440 standard requires the trade name to be accompanied by a petrographic name, a colour and a place of origin. Asking for these three items is worth more than trusting a name.

Frequently asked questions

Can you visit a marble quarry in Carrara?

The basin’s quarries are working industrial sites, about 70 according to Legambiente’s survey, not sites open to visitors. The massif is, however, a UNESCO Global Geopark with more than 250 geosites, and Geoparks have an explicit mission of geological outreach to the public.

Practical arrangements therefore depend on each operator and on the bodies that run the Geopark. They are not given here because no primary source publishes them in consolidated form. The two contacts to approach are the Parco Regionale delle Alpi Apuane, which manages the Geopark, and the Carrara tourist office.

What is the origin of Carrara marble?

A marine limestone. The protolith is a massive Lower Lias carbonate platform limestone, attributed to the Hettangian, about 210 to 200 million years ago. It became marble through greenschist-facies metamorphism, with a peak temperature estimated between 350 and 450 °C, and was then deformed during the building of the Apennines in the Tertiary.

Does Calacatta account for 5% of Carrara’s production?

Nothing supports that claim. The ratio has spread from an unsourced commercial page, and no public breakdown of the basin’s production by variety exists. What is documented is the total volume: 656,000 tonnes of blocks in 2023 in the municipality of Carrara, a historic low.

Is Carrara marble always white?

No. The Apuan basin also produces greys, violets and breccias: Bardiglio, Paonazzo, Arabescato, Zebrino, Nuvolato, Cremo, Seravezza breccias, cipollini. White dominates Carrara’s image because it dominates demand, not because it is the massif’s only rock.

Is Carrara marble suitable for a worktop?

Mechanically yes, chemically with a reservation. Its dominant mineral is calcite, at 3 on the Mohs scale, which dissolves in a weak acid: vinegar, lemon, wine. The detailed comparison is on our page marble or granite for a worktop.

In summary

Carrara marble is better understood through its geology than through its sales names. A Lias limestone, moderate metamorphism, recent Apennine deformation: that is where the homogeneity of a Bianco Carrara and the brecciated structure of a Calacatta come from. The figures, for their part, describe a shrinking basin, where less than a quarter of the volume extracted leaves as blocks. To look at materials and check the petrographic name on a batch, contact us.

A “type of marble” almost always refers to a trade name, not a rock. The European standard NF EN 12440, “Natural stone, denomination criteria” (November 2017) requires that name to be accompanied by a petrographic name, a colour and a place of origin. Without these three pieces of information, “black marble” says nothing about the stone.

This page serves as the index to our materials library: it classes the stones sold as marble according to their real nature, then points to the guide for each family. For formats, see our marble tiles.

Key points

• A marble, in the geological sense, is a metamorphosed limestone. Many commercial “marbles” are non-metamorphosed limestones, serpentinites or breccias.
• Nero Marquina is declared “limestone” under NF EN 12407 by its own producer. Belgian petit granit is a limestone. Nero Assoluto is a gabbro.
• “Guatemala green marble” is a serpentinite, and it comes from India. “Verde Alpi” covers two deposits, one French and closed, the other Italian and active.
• Three separate bodies of standards carry the same names: natural stone (NF EN 1469, 12057, 12058), agglomerated stone (NF EN 14618, 14617, 15285, 15286), ceramics (NF EN 14411).
• Three requests settle the matter with a supplier: the NF EN 12407 petrographic name, the batch declaration of performance, and the NF EN 16301 staining test.

Marble in the geological sense, marble in the commercial sense

The two meanings do not coincide. A marble is, in the petrographic sense, a metamorphic carbonate rock: a limestone recrystallised by heat and pressure, whose original fossils and bedding have disappeared in favour of interlocking calcite grains. The description is that of theEarth Sciences Museum at the University of Waterloo.

In the commercial sense, “marble” means anything that takes a polish and is sold as a slab. Nero Marquina is the clear case: its data sheet declares the name “limestone” under NF EN 12407, and its rudist fossils are intact. A rock that has kept its fossils has not been metamorphosed. It therefore behaves like a limestone: calcite dissolves in a weak acid, whereas the silicates of a gabbro or a granite resist it. That is the difference detailed in our comparison marble or granite.

Three families of standards behind the same names

The same trade name can fall under three separate bodies of standards. A single question settles it: under which standard is the product declared?

• Natural stone : NF EN 1469 (walls), NF EN 12057 (modular tiles), NF EN 12058 (floors and stairs), April 2015. These standards explicitly exclude artificially agglomerated stone materials. It is written in them.
• Agglomerated stone : NF EN 14618 (terminology, October 2009), NF EN 14617 (tests), NF EN 15285 and 15286 (products). An agglomerated stone is an industrial product based on hydraulic cement, resin or both, and stone fragments.
• Ceramic : NF EN 14411, “Ceramic tiles, definitions, classification, characteristics, assessment and verification of constancy of performance and marking”, November 2016. A body of standards separate from those for natural stone and agglomerated stone.

The petrographic name is the scientific name of the rock, established by microscopic examination to NF EN 12407; it is what NF EN 12440 requires alongside the trade name. An agglomerate and a porcelain stoneware tile have none. Asking for it therefore separates the stone from its imitation, right down to marble mosaic.

Trade name, real nature, origin

Here are the most common cases on the French market, with the petrographic nature established by source and the consequence in use. Several rows are documented by the producer itself.

Three of the four black stones in the table bear a name that contradicts their nature. Petit granit is a compact limestone with 96% calcium carbonate according to the Belgian trade federation, and Nero Zimbabwe is a gabbro, writes an Italian processor. On a marble worktop, the distinction determines tolerance to acids.

The main colour families

White: the Carrara basin

These are true marbles, and the only ones whose metamorphism is documented: a Lower Lias limestone, metamorphosed in the greenschist facies. Bianco Carrara is homogeneous, pearl grey with smoky-grey veining. Statuario, purer, is ivory white with rare veining. See also quarry extraction.

Black: four stones, four natures

“Black marble” is the most misleading name on the market: two limestones, a limestone called granite, and a gabbro. The first three react to acids, the last does not. On a polished black, a light mark is rarely a deposit; it is a loss of polish: see white stain on black marble.

Green: serpentinites, not marbles

No green sold as marble is a marble: they are serpentinites and ophicalcites, for which one university publication lists more than sixty trade names. The mixing water of an adhesive mortar reacts with the serpentine minerals, the slab curves, debonds and cannot be relaid. They are laid with a two-component epoxy adhesive complying with ANSI A118.3.

Calacatta: a breccia, not a designation

Calacatta is distinguished from Bianco Carrara by the structure of the rock, not by taste: it is a breccia, whose muscovite-chlorite matrix gives the bold, gold to ochre veining. Nine basins in the Frigido valley yield only seven geological varieties for more than fifty local names. Details in Calacatta or Carrara.

Beige and grey: ask for the petrographic name

The Apuan grey is called Bardiglio, alongside Cremo, Paonazzo and Arabescato. The beiges on the market, for their part, are documented by no source verified to date, and their name indicates neither metamorphism nor deposit. Insist on the petrographic name before ordering a made-to-measure marble floor.

What to ask a supplier for

Three documents are enough, and they all exist.

• The petrographic name under NF EN 12407. Microscopic examination tells you whether the stone is a marble, a limestone, a serpentinite or a gabbro.
• The batch declaration of performance : porosity and density under NF EN 1936, water absorption under NF EN 13755, frost resistance under NF EN 12371. Frost resistance is not a property of the variety. For Nero Marquina, one producer declares it resistant, another does not determine it.
• The NF EN 16301 staining test, resistance to accidental staining, March 2021. It has existed for five years and no data sheet consulted publishes it.

These three documents dictate care. A carbonate stone is cleaned with a neutral detergent, never with vinegar, and a water repellent slows penetration without making the surface waterproof. For accidents, see removing stains and the case of rust stain.

Frequently asked questions

What are the main types of marble?

The market classes them by colour: Carrara whites, Spanish, Italian and Belgian blacks, greens, brecciated Calacattas, greys and beiges. This grid is commercial, not geological. Among the blacks and greens, most of the stones are limestones, serpentinites or gabbros.

Is green marble a real marble?

No, in almost every case. NF EN 12670 treats serpentinite as a distinct rock, with an explicit cross-reference to the entry “green marble”. The consequence is practical: these stones are sensitive to mixing water and are laid with reactive adhesive.

How can you tell a marble slab from a marble-effect porcelain stoneware tile?

By the repetition of the pattern and by the thickness. One manufacturer states that its “Calacatta Gold” reference exists in four designs in 6 mm and two in 12 mm: the pattern comes round again after a few slabs. A natural stone never repeats, and it is not cut to 3 mm.

Is Calacatta a protected designation?

No. In 2026, no specification defines a “Calacatta Gold” or a “Calacatta Borghini”. A “Marmo di Carrara” certification mark has been in the making since the Osservatorio del Marmo agreement of 4 August 2026. It covers Carrara marble, not the sub-names.

In summary

Types of marble are read on a data sheet, not on a label. NF EN 12440 already requires a petrographic name, a colour and an origin: asking for them rules out most misunderstandings, from limestone sold as marble to porcelain stoneware named after a quarry. To check a name for your project, contact us.

See also: Green marbles: Guatemala, Alps, Maurin, verde mare