Technical material reference

Read the stone before specifying it

Compare named stones and geological families by composition, mineral hardness, source-bounded absorption, British weather exposure, care and established uses.

Reference only: no entry is a stock list, offer of supply, physical sample or record of work completed by this atelier.

Open the stone reference

Reference diagram — not a stone sampleThe diagram carries no evidence of colour, grain, veining, finish, source or availability.

How to read the data

Four boundaries keep comparison honest

Mineralogy helps explain likely behaviour, but specification values must come from representative tests on an identified source. Historic repair also requires physical, chemical and mineralogical compatibility.

Names are not specifications: Record the geological and commercial name, quarry, bed or quarry face, block or batch, finish and supplier. Historic England advises matching chemical, physical and mineralogical properties for repair.
Mohs is a mineral scale: Calcite 3, feldspar 6 and quartz 7 describe relative scratch resistance of minerals. They are not whole-stone abrasion, strength or frost values.
Absorption figures are bounded: Every number on this page is tied to the named product or test sample and method. It must not be transferred to another bed, quarry, block or finish.
UK exterior use is conditional: Rain, saturation, freeze–thaw, salts, thermal cycling, orientation, thickness, joints and drainage act together. “Outdoor suitable” is not a family-level property.

Visual references

What stone families can look like

Illustrative stock and public-domain images of stone variation and source context. None is an approved sample, current stock, finish or proof of supply; natural stone varies.

Close material-reference photograph of white Kymi marble from Euboea, showing natural surface variation at hand-sample scale. — Illustrative CC0 material reference of Kymi marble — not our sample, current stock, approved finish or proof of supply; natural stone varies.“Marble Kymi Euboea Greece” by Jebulon, via Wikimedia Commons (CC0 1.0). Local copy resized and converted to WebP.

Macro material-reference photograph of Cretaceous Untersberg limestone, commercially called Untersberg Marble, with a 10 mm scale bar. — Illustrative CC0 macro reference of Untersberg limestone — not our sample, stock, approved finish or proof of supply; the source image includes a 10 mm scale.“Untersberger M2” by Lysippos, via Wikimedia Commons (CC0 1.0). Local copy resized and converted to WebP.

Macro material-reference photograph of Amazon Gold graphic granite from Brazil, showing feldspar, quartz and dark mica at slab-detail scale. — Illustrative CC BY material reference of Amazon Gold graphic granite — not our sample, stock, approved finish or proof of supply; natural stone varies.“Amazon Gold Granite (graphic granite) (Brazil) 4” by James St. John, via Wikimedia Commons, licensed under CC BY 2.0. Local copy resized and converted to WebP. (source, CC BY 2.0)

Close material-reference photograph of sandstone ashlar at the University of Melbourne, showing bedding and joints at masonry-block scale. — Illustrative CC0 sandstone masonry reference — third-party building fabric, not our material sample, supply, installation or completed work.“Sandstone Texture” by cogdogblog, via Wikimedia Commons (CC0 1.0). Local copy resized and converted to WebP.

Aerial stock photograph of a marble quarry near Thessaloniki, showing extracted blocks at quarry scale. — Illustrative Pexels stock photograph of a Thessaloniki marble quarry — not our quarry, supplier, source, stock or supply-chain evidence.Photo by K (@kelly) on Pexels; used under the Pexels License. Local copy resized and converted to WebP.

Named British stones

Regional names still require a quarry and bed

These names describe established building-stone traditions, not uniform commodities. Published figures below belong to the identified supplier product or historic test sample.

Portland stone

Upper Jurassic oolitic and bioclastic limestone

Stone from the Portland Stone Formation, particularly the Isle of Portland. Whitbed, Basebed and Roach are distinct beds and must not be treated as interchangeable.

Mineral composition: Calcite-rich oosparite: ooliths with shell and echinoderm fragments in sparitic and micritic carbonate; the cited Heritage product also records minor quartz and open voids.
Hardness: Calcite is Mohs 3. Minor quartz is Mohs 7, but that does not give the whole rock a Mohs value of 7; Mohs is a mineral scratch scale, not a stone acceptance test.
Water absorption: Heritage Portland Stone: 5.85% by mass average, with 3.16–9.76% lowest/highest expected values from 133 tests to BS EN 13755.Published reference
UK exterior exposure: Conditional, with a long UK service record. The Heritage Whitbed sheet reports flexural results after 14, 56 and 168 freeze–thaw cycles and advises detailing that sheds rainwater. Confirm the proposed bed, section, exposure and current declaration.Published reference
Maintenance: Inspect joints, drips and runoff routes; prevent persistent saturation. Use the least aggressive cleaning method after a trial area, avoid acids and high pressure, and obtain stone- and soiling-specific advice.
Typical uses: Ashlar, façades and cladding, mouldings, carving, monuments, internal flooring and, where the selected product is declared for it, external paving.

Bath stone

Middle Jurassic oolitic limestone

Freestone from the Chalfield Oolite Formation around Bath and Corsham. Quarry and bed names matter: Top Bed and Base Bed products have different porosity, strength and exposure guidance.

Mineral composition: Fine- to coarse-grained ooid limestone with sparry calcite cement and little matrix; the Stoke Ground Base Bed product is classified as oosparite.
Hardness: The dominant calcite mineral is Mohs 3. This indicates scratch sensitivity only and does not replace abrasion, strength or frost testing of the stone.
Water absorption: Stoke Ground Base Bed: 8.6% by weight to BS EN 13755, with 20.7% open porosity by volume to BS EN 1936.Published reference
UK exterior exposure: Conditional by bed and detail. The cited Base Bed is declared at 56 cycles to BS EN 12371 and is promoted for exposed details; that result must not be transferred to another Bath stone or bed.Published reference
Maintenance: Keep copings, cornices and joints draining; avoid cement-rich repairs that trap moisture. Clean only after identifying soiling, use non-acidic products and trial the proposed method.
Typical uses: Ashlar walling, restoration, carved and moulded work, cornices, copings, fireplaces and internal flooring, subject to the selected bed.

Ancaster stone

Middle Jurassic oolitic and bioclastic limestone

Lincolnshire Limestone traditionally worked as Weatherbed, Hard White and Freestone. Historic BRE guidance records materially different weathering behaviour between beds.

Mineral composition: The Goldholme sample is classified as biosparitic limestone with ooliths and fossil fragments in coarse sparite cement; staining identified calcite in constituents and cement.
Hardness: Calcite is Mohs 3. A product’s dense fabric may improve wear or weathering, but does not change the mineral-scale scratch reference.
Water absorption: Goldholme/BRE sample: 4.2% by mass to BS EN 13755. Historic BRE Weatherbed Blue: 3.82% by weight. Historic BRE Hard White: not determined.Published reference
UK exterior exposure: Bed-specific confirmation is essential. Historic BRE guidance describes Weatherbed Blue as suitable for all but the most exposed locations with careful water shedding, while Hard White has limited weathering and salt resistance. The cited sheets do not provide a transferable current freeze–thaw declaration.To be confirmed by testing
Maintenance: Record the bed and bedding orientation, keep projections and joints dry by design, monitor salt and edge decay, and use low-impact non-acidic cleaning after trials.
Typical uses: Ashlar and walling, carved details, mouldings, restoration, fireplaces and selected paving or flooring where the exact bed and finish are supported.

Cotswold stone

Regional family of Jurassic oolitic limestones

A regional description covering limestones from several formations, quarries and beds. The reference value here is for Guiting Gold and is not a Cotswold-wide average.

Mineral composition: Guiting Gold is oolitic limestone with ooliths, bioclasts and intraclasts in coarse carbonate cement, notable quartz grains and minor iron minerals that contribute to its warm colour.
Hardness: The carbonate framework is principally calcitic, so Mohs 3 is the relevant dominant-mineral reference; quartz grains are Mohs 7.
Water absorption: Guiting Gold: 9.6% by weight to BS EN 13755, with 25.7% open porosity by volume to BS EN 1936.Published reference
UK exterior exposure: Conditional and product-specific. Guiting Gold reports 56 cycles for masonry and cladding flexural testing after 14 freeze–thaw cycles. Drainage, bedding, thickness and exposure still require review.Published reference
Maintenance: Preserve breathable, compatible joints; prevent saturated ledges and trapped runoff. Allow natural patination and use gentle, trialled, non-acidic cleaning rather than routine aggressive washing.
Typical uses: Walling, ashlar, architectural masonry, carving, landscape work and repair where colour, texture and physical compatibility have been checked.

York stone

Regional and commercial family of Carboniferous sandstones

“York stone” is not one quarry product. The technical reference below is Crosland Hill Hard York Stone, a fine- to medium-grained Millstone Grit sandstone.

Mineral composition: Sandstone grains commonly include quartz, feldspar and mica, compacted and cemented together. Exact grain and cement proportions require petrography of the offered York stone.
Hardness: Quartz is Mohs 7 and feldspar Mohs 6; whole-stone wear also depends on grain bonding, cement, pores, bedding and finish.
Water absorption: Historic BRE Crosland Hill reference: 2.4% by weight, with 8.6–9.2% porosity and a 0.60–0.68 saturation coefficient.Published reference
UK exterior exposure: The cited Crosland Hill sheet records 14.3 MPa flexural strength after freeze–thaw and assesses the product as durable for paving, masonry and cladding. Do not transfer that conclusion to an unnamed York stone.Published reference
Maintenance: Lay and detail with the correct bedding orientation, keep joints and falls draining, remove organic growth gently and avoid indiscriminate sealing or high-pressure cleaning.
Typical uses: External paving, steps, setts, kerbs, walling, cladding, landscape features and heavily trafficked floors where finish-specific slip data are supplied.

Named Italian marbles

White appearance does not equal one performance

Carrara and Statuario are commercial and geographical selections within marble. Veins, grain fabric, quarry face and block can change strength and weathering behaviour.

Carrara marble

Metamorphic carbonate rock from the Carrara district

A broad geographical and commercial family with multiple grades and quarry faces. The numerical reference is Bianco Carrara C/D from Marmi Carrara’s Lorano quarry.

Mineral composition: The cited C/D marble is predominantly calcitic, with dolomitic crystals in veins plus minor muscovite, rare quartz and disseminated pyrite.
Hardness: Dominant calcite is Mohs 3. Vein minerals can differ, and a polished finish remains vulnerable to acidic etching even when water absorption is low.
Water absorption: Bianco Carrara C/D: 0.11% mean at atmospheric pressure to EN 13755; 0.3% mean open porosity to EN 1936.Published reference
UK exterior exposure: Project-specific review required. The cited product reports 17.2 MPa mean flexural strength dry and 14.4 MPa after 48 frost cycles, but marble can also lose strength or bow through moisture and thermal cycling. Assess carving thickness, veins, fixings, exposure and EN 14066 evidence.To be confirmed by testing
Maintenance: Blot spills promptly; use pH-neutral, non-abrasive products. Avoid vinegar, citrus, descalers and acidic masonry cleaners; agree whether etching and patina are acceptable before selecting a polished finish.
Typical uses: Interior floors and wall linings, stairs, bathrooms, fireplaces, vanity tops, sculpture and carefully assessed exterior work.

Statuario marble

White marble selection from the Apuan Alps

A premium commercial selection characterised by a white ground and grey veining. Quarry face, block, vein fabric and supplier selection must be recorded.

Mineral composition: Recrystallised carbonate marble, normally calcite-dominant. The cited supplier sheet does not publish a detailed mineral list, so EN 12407 petrography remains required for a specification.
Hardness: Calcite’s Mohs hardness is 3. Treat that as a constituent-mineral scratch reference, not proof of whole-stone wear, strength or stain resistance.
Water absorption: Max Marmi Statuario: 0.22% mean at atmospheric pressure to EN 13755, standard deviation 0.12; 0.5% open porosity.Published reference
UK exterior exposure: Project-specific review required. The sheet reports 4.9 MPa mean flexural strength dry and 4.5 MPa after 48 frost cycles, and explicitly recommends new tests for the project. Exterior marble also needs thermal/moisture assessment.To be confirmed by testing
Maintenance: Use pH-neutral cleaners, soft tools and prompt spill removal. Avoid acids and abrasives; test stain treatment and any impregnator on the approved finish and accept that etching may alter gloss.
Typical uses: Feature wall linings, selected floors and stairs, bathrooms, vanity tops, tables, fireplaces and sculpture; exterior work only after source-specific assessment.

Geological families

Family traits are a screening tool only

Granite, sandstone, limestone and white marble cover many rocks. Family-level mineralogy can inform a shortlist, but it cannot supply project test values.

Granite

Coarse-grained intrusive igneous rock family

A geological family, not a colour or a single commercial product. Some stones sold as “granite” in the trade are geologically different rocks.

Mineral composition: Interlocking quartz, feldspar and mica in varying proportions; amphibole and other accessory minerals may occur.
Hardness: Typical principal minerals span feldspar at Mohs 6 and quartz at Mohs 7; mica is softer. There is no single whole-rock Mohs number.
Water absorption: No family value is defensible. Obtain BS EN 13755 results for the exact commercial stone, quarry, finish and supplied production.To be confirmed by testing
UK exterior exposure: Often a strong candidate for exposed work, paving and monuments, but not automatically suitable. Verify freeze–thaw, strength, oxidation-prone minerals, salts, finish-specific slip and fixing design.To be confirmed by testing
Maintenance: Remove spills and salts promptly with a compatible neutral cleaner; avoid abrasive routines that dull a finish. Specify any impregnator only after absorption and finish trials.
Typical uses: Paving, setts, kerbs, steps, cladding, worktops, monuments, sculpture and high-wear floors.

Sandstone

Cemented sedimentary sand-grain rock family

A highly variable family ranging from dense quartz-rich stone to porous stone with weaker clay or carbonate cements.

Mineral composition: Usually quartz with possible feldspar, mica and rock fragments; grains may be cemented by silica, calcite, iron oxides or clay minerals.
Hardness: Quartz is Mohs 7 and feldspar Mohs 6, but surface loss can occur when cement or bedding is weak. Mineral hardness alone does not predict durability.
Water absorption: No family value is defensible. Confirm atmospheric absorption to BS EN 13755, capillary uptake where relevant, porosity and saturation behaviour for the named source.To be confirmed by testing
UK exterior exposure: Ranges from highly durable to unsuitable for exposed thin details. Review bedding direction, pore structure, clay content, salts, freeze–thaw and wetting/drying evidence for the actual stone.To be confirmed by testing
Maintenance: Maintain falls and open drainage, keep the correct bedding orientation, use soft brushes and controlled water, and avoid high pressure or untested sealers that may trap moisture.
Typical uses: Walling, paving, steps, cladding, landscape features, masonry and carving where the grain and cement permit.

Limestone

Carbonate sedimentary rock family

A family containing compact, oolitic, fossiliferous, chalky and dolomitic stones with widely different pore structures and strengths.

Mineral composition: Predominantly calcium-carbonate minerals, usually calcite; dolomite, quartz, clay, iron minerals, fossils and other constituents may occur.
Hardness: Calcite is Mohs 3. Dolomite is somewhat harder, but the whole stone’s abrasion and edge performance must be tested rather than inferred.
Water absorption: No family value is defensible. The named British limestones above range materially even within one region; obtain BS EN 13755 data for the exact bed and product.To be confirmed by testing
UK exterior exposure: Entirely source-, bed-, geometry- and exposure-dependent. Require freeze–thaw evidence for exterior use and design to minimise saturation, salt loading and vulnerable thin projections.To be confirmed by testing
Maintenance: Avoid acids, aggressive descalers and high pressure. Use compatible breathable repairs, control runoff and test cleaning on a discreet area before proceeding.
Typical uses: Ashlar, walling, cladding, flooring, fireplaces, carving, mouldings and paving where source-specific evidence supports the use.

White marble

Visual and commercial family of pale metamorphic carbonate rocks

A colour-led description, not a geological source. It may include calcitic or dolomitic marbles with very different grain fabrics, veins and accessory minerals.

Mineral composition: Recrystallised carbonate minerals, commonly calcite and sometimes dolomite, with source-specific veins and accessory minerals.
Hardness: Calcite-dominant marbles use Mohs 3 as the principal mineral reference. That does not describe veining, etching, flexural strength or thermal stability.
Water absorption: No family value is defensible. Carrara C/D and the cited Statuario sheet report different means; test the exact offered block or representative production to EN 13755.To be confirmed by testing
UK exterior exposure: Do not infer suitability from low absorption or colour. Confirm frost performance, flexural strength after conditioning, thermal cycling/bowing risk, moisture exposure, vein orientation, thickness and fixing design.To be confirmed by testing
Maintenance: Use pH-neutral non-abrasive cleaners, remove spills promptly and avoid acids. Agree the acceptable patina, etching and gloss change; trial any stain treatment or impregnator.
Typical uses: Sculpture, fireplaces, interior floors and wall linings, bathrooms, stairs, vanity tops and worktops where etching and staining expectations are explicit.

Specification gap register

What still needs source-specific evidence

Published reference values support a shortlist. They do not approve an unidentified supply or a proposed exterior detail.

01
Supply identity
Confirm the exact commercial and geological name, country, quarry, bed or face, block/batch route and any resin, filler, sealer or other treatment.
Applies to: All 11 references
02
Petrography
Obtain current BS EN 12407 petrography where composition, deleterious minerals, veins or compatibility affect the decision.
Applies to: All offered stones
03
Water and pore data
Confirm BS EN 13755 absorption and relevant density, open porosity, capillary or saturation data on representative production.
Applies to: Granite, sandstone, limestone and white marble; plus any different named supply
04
Exterior durability
Confirm BS EN 12371 freeze–thaw evidence and retained strength appropriate to the product form, exposure and design life.
Applies to: Every proposed outdoor use; especially the exact Ancaster bed
05
Marble thermal stability
Assess moisture plus thermal cycling, including EN 14066 where relevant, together with veins, thickness and fixing design.
Applies to: Carrara, Statuario and other white marble outdoors
06
Finish and exposure tests
Confirm wet slip, abrasion, salt or chemical resistance as relevant, then approve cleaning and treatment trials on the actual finish.
Applies to: Paving, floors, salts, water features and stain-prone settings

Source register

21 traceable online sources

Supplier values are cited as declared references, not endorsements. Historic sheets remain useful evidence but should be replaced by current declarations for procurement.

Full editorial notes are held in docs/sources/materials-sources.md.

SFG01 — Choosing and using natural stone for your home Stone Federation Great Britain: Accessed 20 July 2026
SFG02 — Natural stone in and around swimming pools Stone Federation Great Britain: Accessed 20 July 2026
SFG03 — Six pitfalls to avoid when specifying stone in hotel design Stone Federation Great Britain: Accessed 20 July 2026
SFG04 — Cleaning natural stone buildings Stone Federation Great Britain: Accessed 20 July 2026
HE01 — Sourcing stone for historic building repair Historic England: Accessed 20 July 2026
HE02 — Building Stones of England Historic England: Accessed 20 July 2026
BGS01 — Rocks and minerals British Geological Survey: Accessed 20 July 2026
USGS01 — Natural gemstones: mineral hardness United States Geological Survey: Accessed 20 July 2026
BGS02 — BGS Lexicon: Portland Stone Formation British Geological Survey: Accessed 20 July 2026
BGS03 — Geology of the Bath area: building stone British Geological Survey: Accessed 20 July 2026
BGS04 — Moreton-in-Marsh district: local limestones and building stone British Geological Survey: Accessed 20 July 2026
SUP01 — Heritage Portland Stone technical data sheet Albion Stone: Accessed 20 July 2026
SUP02 — Stoke Ground Base Bed Bath Stone Bath Stone Group: Accessed 20 July 2026
SUP03 — Testing of Ancaster Limestone Goldholme Stone / BRE: Accessed 20 July 2026
BRE01 — Ancaster Limestone — Weatherbed Blue Building Research Establishment: Accessed 20 July 2026
BRE02 — Ancaster Limestone — Hard White Building Research Establishment: Accessed 20 July 2026
SUP04 — Guiting Gold Cotswold Limestone technical data Johnston Quarry Group: Accessed 20 July 2026
BRE03 — Crosland Hill Sandstone technical data sheet Building Research Establishment / Johnsons Wellfield: Accessed 20 July 2026
SUP05 — Bianco Carrara C/D physical and mechanical characteristics Marmi Carrara: Accessed 20 July 2026
SUP06 — Statuario technical data sheet Max Marmi Carrara: Accessed 20 July 2026
RES01 — Durability of marble cladding: a comprehensive literature review TEAM research project / Environmental Geology: Accessed 20 July 2026

Next step

Specify a source, not a family name

Name the intended setting, water and frost exposure, likely contact and finish, then ask the supplier to identify the exact quarry, bed and representative technical evidence.

Open the enquiry prototype View the process

An enquiry is not an order. Feasibility, scope, price, programme and delivery terms are confirmed in writing before either party makes a commercial commitment.