What every stone inspection covers
Stone is sold on looks and dimensions, and both vary from block to block. Two containers cut from different blocks of the same named stone can look like two different products. An inspection is therefore a check that the factory cut, finished, sorted and packed that variation the way you agreed. Every stone inspection runs the same core steps:
- Quantity and lot. Pieces, square metres or sets against the purchase order, by size, finish and colour lot. Slab numbers and block numbers recorded where the stone is sold in sequence.
- Colour, vein and grain. Pieces laid out together in daylight and compared with the approved sample and with the agreed lightest and darkest limit pieces.
- Dimensions. Length, width, thickness at several points, diagonals for squareness, and flatness with a straightedge and feeler gauge.
- Surface finish. Polish level with a gloss meter where specified, honed or flamed texture against the sample, saw marks, grinder burns and patches.
- Cracks, fissures and repairs. Faces wetted and viewed in raking light; resin fills, mesh backing and patches looked at on both faces.
- Edges and corners. Chips, spalls and arris finish on every visible edge.
- Packing and marking. Crates, bundles and A-frames for strength and bracing, interleaving between polished faces, and labels that match the packing list.
Tiles, paving and memorial components are sampled by ISO 2859-1; see the AQL guide. Large slabs are often checked one by one, because every slab is different and a buyer is paying for each one. Each finding is classed critical, major or minor, and the report ends in one verdict: Cleared to load, Hold or Not cleared.
How the checklist changes by product
| Product | Main risk | What the inspector adds |
|---|---|---|
| Granite slabs, tiles and countertops | Dyed or resin-coloured stone; thickness and polish varying across a lot; cracked cut-outs on worktops | Solvent wipe for dye, gloss readings per slab, calibration of tiles, cut-out corners and edge profiles against the drawing |
| Marble slabs and tiles | Fissures held together only by resin and mesh; veining that does not match across a floor | Back-face check of mesh and resin, bookmatch and lay-out of numbered slabs, scratch and etch check on the polish |
| Granite memorials and headstones | Wrong lettering; parts that do not fit together; no proof of ethical sourcing for German cemeteries | Proof-reading every inscription, dry-fit of dowels and bases, colour match between parts, sourcing documents |
| Sandstone paving | Thin or laminated slabs that split in frost; colour lots mixed on a patio | Thickness against the calibration class, splitting along bedding planes, iron spots, pack contents and crate condition |
Carved and inlaid stone sold as décor is covered under marble and stone décor, and marble tops on tables under marble and stone top furniture. This industry covers stone sold by the square metre, the set or the crate, mostly to building, landscaping and memorial trades.
Reading the stone: veins, fissures, cracks and resin
Most stone disputes come down to one question: is this mark part of the stone, or is it damage? Three distinctions are worth writing into the specification.
Vein or crack. A vein is a band of different mineral that is part of the stone and does not open. A crack is a break. Wetting the face helps: water stays in an open crack a moment longer and shows it as a dark line while the rest of the surface dries. A crack catches a fingernail; a vein does not.
Fissure. Many marbles and some granites have natural fissures, narrow openings along a vein that may never move. Factories fill them with resin and often glue a fibreglass mesh to the back of the slab. That is normal practice for many stones, but it should be agreed. A fissure that runs right through the thickness, or resin that is cloudy, sunken or the wrong colour, is a defect.
Dye and coatings. Some granites, especially blacks, are coloured or treated with resin to deepen the colour. A cloth wetted with acetone and rubbed on a hidden area picks up dye. Resin treatment is not wrong in itself, but it changes how the stone weathers outdoors and must match what was ordered.
The inspector records what was found and how it compares with your limit samples. Where a mark is a judgement call, the report shows a photo so you can decide.
Market rules that shape the checklist
| Market | Rule or standard | What it means at the factory |
|---|---|---|
| EU and GB | Harmonised European standards for natural stone: EN 1341 (external paving slabs), EN 1469 (cladding slabs), EN 12057 (modular tiles), EN 12058 (floor and stair slabs) | A declaration of performance and CE marking from the manufacturer; markings and dimensional classes on the packs that match it. GB still accepts CE for construction products; see UKCA and CE marking |
| US | ASTM C503 (marble), C615 (granite), C616 (quartz-based stone such as sandstone) | Material specifications buyers quote in contracts; test reports from a lab for the stone actually quarried |
| UK | BS 8415, memorials in burial grounds | Component sizes, fixing holes and dowels as designed for the fixing system the mason will use |
| Germany | State burial laws, for example Art. 9a of Bavaria's Bestattungsgesetz | Cemetery bylaws may require proof that natural stone memorials were made without the worst forms of child labour |
| All | Wooden crates and A-frames | ISPM 15 treatment and marks |
An inspector checks markings, dimensions, documents and the stone itself. Flexural strength, water absorption, freeze-thaw and slip resistance are measured by an accredited lab on pieces cut from your stone; we can pull and seal them through lab testing coordination.
Ethical sourcing and child labour due diligence
Stone is one of the products where buyers are most often asked where it came from. The US Department of Labor's List of Goods Produced by Child Labor or Forced Labor includes stones and sandstone from India. In the UK, organisations with a turnover of £36 million or more must publish an annual modern slavery statement. The EU's forced labour regulation, Regulation (EU) 2024/3015, will ban products made with forced labour from the EU market from 14 December 2027. In Germany, Bavarian cemeteries may require proof of memorials made without the worst forms of child labour, under ILO Convention 182.
An inspection at a processing factory cannot prove how a quarry is run. What it can do is record the quarry and block numbers the factory declares, check that invoices and transport documents match them, and note who did the work on site. A factory audit adds basic social-compliance observations at the processing unit; it is not a SMETA or amfori BSCI audit and not a certification. For quarry-level assurance, buyers use specialist certification schemes; the inspection then checks that the certificate covers the factory and the stone shipped.
Where stone is quarried and processed in India
Stone is quarried in many states. We name a place only where an official source supports it.
| Place | Source | Stone |
|---|---|---|
| Makrana, Nagaur district, Rajasthan | "Makrana Marble" Geographical Indication (application 405, certificate dated 30 March 2015); Nagaur's One District One Product entry is "Granite/Marble - Makrana" | White marble |
| Prakasam district (Chimakurthy mandal), Andhra Pradesh | One District One Product: "Granite (Black Galaxy)"; the district says the stone is found only in Chimakurthy mandal | Black Galaxy granite |
| Dholpur district, Rajasthan | DC-MSME district industrial profile: hills in the west of the district supply quarries of red sandstone | Sandstone |
India's exports, Department of Commerce TradeStat, FY2025-26 (provisional), US$ million:
| HS code | Product | US$ million |
|---|---|---|
| 6802 23 | Granite, simply cut or sawn (slabs, tiles) | 757.11 |
| 2516 11 | Granite, crude or roughly trimmed (blocks) | 328.14 |
| 6802 21 | Marble, simply cut or sawn | 141.46 |
| 6802 93 | Other worked granite (includes polished memorials) | 132.37 |
| 2516 20 | Sandstone | 64.46 |
| 6801 | Setts, curbstones and flagstones | 34.58 |
Booking a stone inspection
Clear To Load is based in Jodhpur, Rajasthan, with inspectors in Jaipur, Saharanpur, Moradabad, Delhi NCR and Kolkata, and covers every city in India. An inspection costs US$249 per man-day. Quarry towns such as Makrana, Dholpur and Chimakurthy are outside our inspector base cities, so travel there is charged at actual cost; see pricing.
For stone, the most useful check is often at the slab yard before cutting or before final selection, when a slab from the wrong block can still be swapped. A pre-production inspection checks blocks or raw slabs against your sample; a pre-shipment inspection checks finished, packed goods; and container loading supervision checks crate bracing and weight spread, because stone reaches a container's weight limit long before it fills the space. Send the approved sample, limit pieces, drawings and any test reports you hold.
Sources
- IP India GI Registry: Makrana Marble, application 405
- Invest India: national ODOP product list (5 May 2023): Nagaur, Prakasam
- Prakasam district: Black Galaxy granite (ODOP)
- MSME-DI Jaipur: Brief Industrial Profile of Dholpur District
- Department of Commerce, TradeStat: commodity-wise exports (FY2025-26, provisional)
- US Department of Labor, ILAB: India (List of Goods entries)
- Bayern: Bestattungsgesetz, Art. 9a (gravestones and child labour)
- Modern Slavery Act 2015 (Transparency in Supply Chains) Regulations 2015, £36m threshold
- Regulation (EU) 2024/3015 prohibiting products made with forced labour
- BSI: BS 8415, Memorials within burial grounds and memorial sites