Reference
Natural Stone Glossary
Definitions of natural-stone industry terms — stone types, quarrying, fabrication, trade, and EU compliance — for quarries, fabricators, and buyers.
Stone Types
- Granite
- Granite is a coarse-grained igneous rock composed primarily of quartz, feldspar, and mica, formed by the slow cooling of magma deep within the Earth's crust. Its hardness (Mohs 6-7) and low porosity make it one of the most durable cladding and countertop materials. Commercial quarrying is concentrated in Brazil, India, China, and Iberian Europe.
- Limestone
- Limestone is a sedimentary rock composed chiefly of calcite or dolomite, formed from the accumulation of marine organisms and chemical precipitation. It is widely used in architecture, paving, and as a raw material for cement. Porosity and density vary greatly between varieties—from dense Jura Beige to highly porous Coral Stone—making material specification essential.
- Marble
- Marble is a metamorphic rock formed when limestone is recrystallized under heat and pressure, producing the characteristic interlocking calcite crystals prized in architecture and design. It ranges from pure white (Carrara, Thassos) to richly veined polychrome varieties. Because calcite is reactive to acids and relatively soft (Mohs 3-4), marble requires careful specification for interior versus exterior applications.
- Onyx
- Stone onyx is a translucent, banded calcium carbonate (aragonite) formed by spring or cave deposits, distinct from the silica-based onyx used in gemology. Its translucency makes it prized for backlit feature walls and reception counters. Onyx is soft (Mohs 3) and highly sensitive to acids and mechanical impact, limiting its use to low-traffic interior applications.
- Quartzite
- Quartzite is a metamorphic rock formed when sandstone is subjected to intense heat and pressure, fusing quartz grains into an extremely hard, dense matrix (Mohs 7+). It is frequently mislabeled in the trade as marble or granite; distinguishing true quartzite from quartzitic marble is critical for correct maintenance advice and warranty. Popular Brazilian quartzites include Taj Mahal, White Macaubas, and Sea Pearl.
- Slate
- Slate is a fine-grained metamorphic rock derived from shale, notable for its perfect cleavage (foliation) that allows it to be split into thin, flat sheets. It is used for roofing, flooring, wall cladding, and pool surrounds. Natural cleft slate surfaces vary in texture and thickness even within a single pallet, requiring tolerance management during installation.
- Travertine
- Travertine is a sedimentary limestone deposited by mineral springs, characterized by a porous, banded structure with natural voids (pits and troughs). It is classified as filled (voids grouted before polishing) or unfilled (open texture). Major producing regions include Turkey, Iran, and Italy; Turkish travertine dominates the global export market by volume.
Quarry & Extraction
- Bookmatch
- Bookmatching is the technique of opening two consecutive slabs like a book so that their mirror-image vein patterns create a symmetrical composition across a joint. It is widely used for feature walls, fireplace surrounds, and bathroom vanities. Successful bookmatching requires that slabs remain in sequence from the same bundle and that the installer understands which face to flip.
- Bundle
- A bundle is a set of consecutive slabs cut from the same quarry block, stacked in the order they were sawn and sold as a matched unit. Keeping a bundle intact preserves vein continuity for large-format installations such as feature walls and kitchen islands. Industry convention labels bundles sequentially (Bundle 1, Bundle 2) within a lot.
- Gang Saw
- A gang saw is a multi-blade frame saw used in stone processing plants to cut an entire block into slabs in a single pass, using steel-shot abrasive slurry or diamond-tipped blades. The saw type (shot saw vs. diamond multi-wire) affects surface texture, dimensional tolerance, and production speed. Saw marks from shot-blade gang saws require additional grinding before polishing.
- Lot / Batch
- A lot (or batch) is a defined quantity of stone processed from a specific block or group of blocks at a single production run, sharing consistent color, veining, and surface characteristics. Lot traceability is the foundation of quality control: specifying a lot number at order stage prevents color variation between initial delivery and replacement pieces.
- Quarry Block
- A quarry block is the primary unit of raw stone extracted from a quarry face, typically a rectangular prism weighing between 10 and 30 tonnes depending on the material and market. Block dimensions directly determine slab yield and bookmatching potential. Premium blocks are graded by absence of cracks, voids, color consistency, and squareness before sale or processing.
- Slab
- A slab is a thin, flat panel cut from a quarry block by a gangsaw or wire saw, typically 2-3 cm thick and 160-340 cm in length. Slabs are the primary commercial unit for countertops, flooring, and wall cladding. Each slab in a bundle shares continuous veining from the same block section, making bundle-level inventory tracking essential for design matching.
- Vein
- A vein in natural stone is a band of contrasting mineral material—typically calcite, quartz, or oxide deposits—that fills fractures formed during geological activity. Vein pattern, direction, and intensity are primary drivers of aesthetic value in marbles and quartzites. In quarry operations, vein orientation relative to the block cut determines whether the final slab shows a cross-cut (cloud) or vein-cut (linear) pattern.
Fabrication & Finishing
- Calibration
- Calibration is the process of grinding the back face of a stone tile or slab to a uniform thickness within tight tolerances (typically ±0.5 mm). It is mandatory for floor tiles installed with adhesive and for wall panels requiring flush alignment. Uncalibrated stone requires skilled traditional installation with thick mortar beds to compensate for thickness variation.
- Honed Finish
- A honed finish is a matte or satin surface produced by stopping the grinding process before the stone reaches full reflectivity, typically between 400 and 800 grit. It offers a softer aesthetic than polished stone and partially conceals scratches and etching, making it preferred for high-traffic flooring and commercial interiors. Honed marble requires sealing as the open surface absorbs stains more readily.
- Leathered Finish
- A leathered finish (also called brushed or antiqued) is created by passing rotating diamond brushes over a honed surface to produce a textured, low-sheen result that accentuates the stone's natural topography. It is popular for dark granites and quartzites in kitchen applications because it hides fingerprints and water spots better than polished surfaces. Texture depth varies by tool pressure and stone hardness.
- Polished Finish
- A polished finish is a highly reflective, mirror-like surface achieved by progressively grinding natural stone with finer abrasive grits until the crystal structure itself reflects light. It enhances color saturation and veining contrast, making it the most popular finish for marble and granite countertops. Polished surfaces on calcareous stones (marble, limestone, travertine) are vulnerable to etching from acidic substances.
- Resin Treatment
- Resin treatment is the process of impregnating or coating the back (and sometimes the face) of a stone slab with epoxy or polyester resin to consolidate fragile material, fill micro-fissures, and improve structural integrity. It is standard practice for most marbles and quartzites, and mandatory for stones with high fissure content. Resin-treated slabs must be disclosed, as some formulations are incompatible with underfloor heating systems.
- Sandblasted Finish
- A sandblasted finish is produced by directing high-pressure abrasive particles at the stone surface, creating a uniformly rough, matte texture that improves slip resistance. It is specified for exterior paving, pool surrounds, and public circulation areas where wet-surface safety is a primary concern. Sandblasting reduces surface sheen and slightly lightens the natural color of the stone.
Measurement & Technology
- Delta-E (ΔE)
- Delta-E (ΔE) is a numerical measure of the perceptible color difference between two stone samples, calculated in a standardized color space (typically CIELAB). A ΔE below 1.0 is imperceptible to the human eye; values above 3.0 are clearly visible and may constitute a quality non-conformity. Spectrophotometer-based ΔE measurement is increasingly used for lot matching and rejection criteria in premium stone contracts.
- Digital Product Passport (DPP)
- A Digital Product Passport (DPP) is a structured digital record that follows a product through its entire lifecycle, capturing origin, composition, processing, environmental impact, and end-of-life data. The EU Ecodesign for Sustainable Products Regulation (ESPR) is phasing in DPP requirements across construction materials, including stone. For quarries, a DPP links each slab to its extraction site, processing chain, and carbon declaration.
- LiDAR Scanning
- LiDAR (Light Detection and Ranging) scanning uses pulsed laser light to generate precise 3D point-cloud measurements of stone slabs, quarry faces, or installed surfaces. Phone-based LiDAR (iPhone Pro, iPad Pro) enables field measurement of slab dimensions, remnant pieces, and installation surfaces without dedicated hardware. Scan-to-fabrication workflows reduce templating errors and cut material waste.
- Slab Inventory Management
- Slab inventory management is the system-level tracking of individual stone slabs through a yard or warehouse, recording dimensions, bundle position, finish, availability status, and location. Effective management prevents double-selling, enables remnant recovery, and supports accurate reservation workflows. Digital platforms assign unique IDs to each piece, linking them to photos, measurements, and sales records.
- Spectral Color Matching
- Spectral color matching uses spectrophotometry to measure the full reflectance spectrum of a stone surface and compare it objectively against a reference sample or approved standard. It replaces subjective visual grading with quantitative data, enabling remote approval of stone shipments before they leave the quarry. Paired with Delta-E thresholds, it reduces costly disputes at the point of delivery.
- Traceability
- Stone traceability is the ability to document and verify the complete chain of custody for a natural stone product, from quarry face to finished installation. It encompasses block number, lot, processing plant, country of origin, and any treatments applied. Traceability is increasingly required by public procurement rules, LEED/BREEAM certification schemes, and emerging EU supply chain due diligence regulations.
Trade & Commerce
- CIF (Cost, Insurance, Freight)
- CIF (Cost, Insurance, Freight) is an Incoterm under which the seller pays ocean freight and insurance to deliver stone to the buyer's destination port, with risk transferring to the buyer as soon as the goods are loaded at the origin port. CIF pricing simplifies budgeting for importers but limits their control over freight carrier selection. Traders should verify that insurance coverage values reflect current market replacement cost.
- Container Load Planning
- Container load planning is the optimization of how stone slabs, blocks, or tiles are arranged within a shipping container to maximize payload utilization while protecting cargo from damage in transit. A standard 20-foot container carries roughly 18-22 tonnes of slabs on A-frame racks. Poor load planning is a leading cause of stone breakage claims; professional planning tools calculate weight distribution and void-fill requirements.
- Double-Selling
- Double-selling in the stone trade is the accidental or fraudulent allocation of the same slab or lot to more than one buyer, typically caused by manual inventory processes or disconnected sales systems. It is one of the most costly operational failures for stone yards, resulting in contract disputes, project delays, and reputational damage. Real-time digital inventory reservation with reservation locks eliminates the risk at the system level.
- FOB (Free On Board)
- FOB (Free On Board) is an international trade term specifying that the seller delivers stone goods loaded onto the nominated vessel at the origin port, after which risk and cost transfer to the buyer. It is the dominant Incoterm for quarry-to-importer stone transactions. FOB price comparisons between suppliers must account for local haulage, port handling, and export documentation costs, which vary significantly by quarry location.
Compliance & Sustainability
- Environmental Product Declaration (EPD)
- An Environmental Product Declaration (EPD) is a standardized, third-party verified document that quantifies the environmental impact of a product across its lifecycle using Life Cycle Assessment (LCA) methodology conforming to ISO 14040/14044 and EN 15804 for construction products. For natural stone, EPDs typically cover extraction, processing, and transport to gate. EPDs are required for LEED v4.1 credits and are increasingly mandated in European public procurement.
- EU Stone Compliance
- EU stone compliance refers to the set of European regulatory requirements applicable to natural stone products placed on the EU market, including Construction Products Regulation (CPR) CE marking, REACH restrictions on hazardous substances (notably crystalline silica dust), country-of-origin labeling, and emerging ESPR/DPP obligations. Non-compliant stone can be halted at customs or excluded from public tenders. Requirements differ between finished products and raw blocks.
- Global Warming Potential (GWP) Declaration
- A Global Warming Potential (GWP) declaration reports the carbon dioxide equivalent emissions (kg CO₂e) associated with producing a defined quantity of stone, typically expressed per square metre or tonne. It is the core metric within an EPD and the primary data point required by green building rating schemes and EU Taxonomy alignment. Natural stone generally carries a lower embodied carbon footprint than manufactured alternatives such as engineered quartz.
- Silica Dust Regulation
- Silica dust regulation governs occupational exposure limits (OEL) for respirable crystalline silica (RCS) generated during stone cutting, grinding, and fabrication. The EU OEL is 0.1 mg/m³ (Directive 2017/164/EU); OSHA sets a stricter permissible exposure limit of 0.05 mg/m³. Engineered quartz slabs (greater than 90% silica) generate far higher dust concentrations than natural stone during dry cutting, driving mandatory wet-cut and ventilation requirements in fabrication shops.