Natural stone glossary: marble and slab terms explained

The stone trade has a language of its own. These are the terms you will hear most when choosing, ordering or specifying marble, quartzite or onyx, in alphabetical order and in a few words.

A

Absorption

How much water a stone takes up, as a percentage of its weight (EN 13755). The lower it is, the less the stone stains.

Alabaster

A white, translucent stone, softer than marble. Used for lamps, sculpture and backlit indoor features.

Anchor

A metal fixing that holds a panel to a wall or subframe. On ventilated façades: kerf (slot), pin or undercut anchors.

B

Backlighting

Lighting a translucent stone from behind: onyx, alabaster, some quartzites and many semi-precious slabs. See backlit onyx.

Block

A squared piece of stone weighing several tonnes, straight from the quarry, from which slabs are cut. We also sell whole blocks.

Book-match

Consecutive slabs from the same block laid out like an open book, so the veining forms a mirror image. See what is bookmatching.

Bowing

The warping that thin panels of some marbles can develop outdoors through cycles of heat and moisture (EN 16306 test).

Breccia

A stone of broken rock fragments naturally cemented back together, such as Breccia Pontificia.

Brushed

A finish made with abrasive brushes that softens the surface and edges and gives a worn look.

Bush-hammered

A rough, pitted finish made with a bush hammer (a hammer with a toothed head). Very slip-resistant.

C

CE marking

The EU mark for construction stone products covered by a harmonised standard (EN 1469, EN 12057, EN 12058, EN 1341, 1342 and 1343), with its DoP. See how to specify natural stone.

Cladding

Covering a wall with stone panels. See interior stone wall cladding.

Crystallization

A chemical shine treatment for polished marble floors, applied with a rotary machine and steel wool. Only for calcareous stones.

D

Declaration of Performance (DoP)

The document that goes with CE marking and states the product's tested values.

Density

Weight per volume (EN 1936). Marbles, quartzites and granites are around 2,600–2,800 kg/m³ (162–175 lb/cu ft): a 2 cm (¾ in) slab weighs about 52–56 kg/m² (about 11 lb/sq ft), a 3 cm (1¼ in) slab about 78–84 kg/m² (16–17 lb/sq ft).

Dolomitic marble

Marble made of dolomite, somewhat harder and less acid-sensitive than calcitic marble. Some white stones sold as quartzite are dolomite.

Dry lay

Laying out slabs or pieces unfixed, before cutting or installing, to check how the veining flows.

E

Edge profiles

The shape of the visible edge: eased (square, arris softened), bevelled (a small chamfer), half bullnose (rounded on top, flat below), full bullnose (fully rounded) or mitred. See countertop thickness.

Engineered quartz

A manufactured material of crushed quartz and resin. It is not natural stone. See quartzite vs quartz.

Etching

The dull mark lemon, vinegar or wine leave on marble, limestone or onyx by dissolving the calcite. It is damaged surface, not dirt. See marble etching.

F

Fabricator

The workshop that turns slabs into finished pieces and usually installs them (in the UK, often the stonemason). They template the job and prepare the slab layout.

Finish

The treatment of the visible face: polished, honed, leathered… It changes colour, sheen, feel and slip resistance. See natural stone finishes.

Flamed

A rough finish made with a very hot flame. Only for granite and some quartz-rich stones, never for marble.

G

Gang saw

A machine that cuts a block into many slabs at once, with parallel steel blades or, in multi-wire saws, diamond wires.

Granite

An igneous rock of quartz, feldspar and mica, very hard. The trade also gives the name to other similar hard rocks.

H

Honed

A smooth, matt finish: polishing stops before the shine. It hides everyday marks.

L

Leathered

A brushed finish that follows the softer areas of the stone, leaving a gentle relief, a satin sheen and a leather-like feel. Hides fingerprints and water spots.

Limestone

A sedimentary rock of calcium carbonate, often with fossils. Acid-sensitive, like marble. Example: Belgian Blue.

Lot

Slabs from the same block, numbered in cutting order (also called a bundle). Buying from one lot keeps colour and pattern consistent.

M

Marble

A metamorphic rock of recrystallised calcite (or dolomite). It takes a high polish but is soft and acid-sensitive. See types of marble.

Mesh backing

Fibreglass mesh bonded with resin to the back of a slab to reinforce fragile stones such as onyx.

Mitre (miter)

Two pieces cut at 45° and joined. It gives clean corners and edges that look solid.

Mohs hardness

Scratch resistance on a 1-to-10 scale. Calcite, in marble, rates 3; quartz, in quartzite, rates 7: a knife scratches marble but not quartzite.

O

Onyx

A banded, translucent calcite stone, soft and acid-sensitive. It usually has mesh and resin on the back.

P

Patina

The look marble takes on after years of use: small marks and a softer sheen.

Polished

A glossy, mirror-like finish. It deepens colour and veining; on marble it makes etch marks more visible.

Porosity

The percentage of voids inside a stone (EN 1936). The more porous, the more it absorbs.

Primary block

The first huge, irregular mass freed from the quarry face, later divided and squared into blocks. Spanish quarries call it a torta.

Q

Quarry

The place where stone is extracted, open-cast or underground.

Quartzite

A metamorphic rock of fused quartz grains. Much harder than marble and far more resistant to acids. See marble vs quartzite.

R

Resin treatment

Filling pores, hairline cracks and voids with resin at the factory, before polishing. Common in quartzites, breccias, onyx and travertine.

S

Sandblasted

A fine, slip-resistant texture made by blasting sand or grit at the surface.

Sealing

An impregnator that slows the absorption of water and oil. It does not protect against acids. See do you need to seal marble?

Semi-precious slab

Pieces of amethyst, sodalite or another semi-precious stone bonded with resin and polished on a backing panel. Not a solid block. See exotic and semi-precious stone.

Serpentine

A dark green rock sold as green marble, such as Verde Alpi. Moisture-sensitive during installation, so epoxy or polyurethane adhesives are usually recommended.

Slab

A large sheet cut from a block, usually 2 or 3 cm (¾ or 1¼ in) thick. The unit stone is sold and chosen by.

Slab layout

A drawing showing which slab, and which part of it, each piece comes from. See large-format slabs and slab layout.

Slip resistance

How well a floor resists slipping. Spain and the UK use the pendulum test (Rd, PTV); the US uses DCOF. See natural stone slip resistance.

T

Travertine

A limestone deposited by spring water, with characteristic holes that are filled or left open.

V

Vein

A line or band of another colour running through the stone and giving it character.

Vein-cut and cross-cut

The two ways of cutting a block relative to its layers. Vein-cut gives a striped pattern; cross-cut (or fleuri) a cloudy, more uniform one. The terms get mixed up, so describe the pattern or ask for photos.

Ventilated façade

Panels hung from a metal subframe with concealed anchors, a ventilated cavity and outside insulation (a rainscreen). See ventilated stone façade.

W

Waste

The material lost when the pieces are cut. It depends on the slab layout and is higher with book-matching.

Waterfall

A countertop or island where the stone runs down the side to the floor, mitred so the veining carries on. See waterfall countertop.

Wire saw

A steel cable threaded with diamond beads. It cuts stone in the quarry and blocks in multi-wire saws.

Unsure about a term in your project? Browse the catalogue and tell us what you need: we will send photos and videos of the actual slabs, and we ship worldwide.