Glossary of stone terminology and terms

Glossary of terms:

The following is not a complete glossary of stone terms and terminology, but is a selection of the most commonly used terms people will encounter when considering buying stone tiles.

Acid Washed:
Acid washing exposes some of the sand in certain types of stone, giving a rougher texture.

Antique:
This is a general term which can be use to describe the result of various different processes that can be applied to stone tiles. The overall effect of these processes is to create an aged, or worn look.

Brushed:
An ageing process which generates a smoother and worn appearance to certain types of stone. It is most commonly used on unfilled travertine and sandstone.

Bull Nose:
The semi-circular, half rounded edge usually applied to thicker slabs of stone where the sawn edge is either not desired or is not safe. Good examples of where bull nosing is used is on vanity tops, swimming pool coping stones, work surfaces, and bath surrounds.

Calibrated & Un-calibrated:
Quarried stone, which is cut into even thickness tiles, are calibrated tiles. The majority of tiles manufactured for use internally are calibrated. Un–calibrated tiles are the opposite, and where the tiles can vary in depth.

Cross Cut:
This term is usually used to describe one form of travertine. Cross cut travertine tiles give a cross-section of the stone, which is cut horizontally. This is the most commonly used cutting method for travertine.

Cobble:
Usually a smaller format of natural stone used externally as a worn or antique paving stone.

Cushioned:
This describes stone towards the edging of a tile. Cushioned edges gently slope downwards before meeting the sawn edge. The overall effect is slight rounding and softening of the edge. Often this is referred to also as a pillowed edge.

Durability:
Durability describes a stone tiles' capacity to withstand daily foot traffic and everyday wear and tear. Higher durability stone tends to be selected for commercial use, as well as high traffic areas of the home. Medium and lower durability tiles are still fine for use in most domestic areas. Some low durability tiles should be restricted to use in low traffic areas.

Filled:
This is the term used to describe travertine tiles which have none of the naturally forming pits and holes visible in the surface of the stone. Instead a resin is used to fill the holes and create a perfectly smooth and flat travertine tile. Filled tiles are always honed as well as filled.

Filling:
This is the inserting of either resin, as described in “filled” or grout, which can also be used to fill travertine after tiles have been fitted.

Flag:
A slab like piece of stone usually in larger sizes, most commonly used externally on patios, driveways and paths. Various styles, edgings and surface finishes are available.

Flamed:
The process by which stone (usually marble or granite) is treated with intense heat as a form of aging tiles. The stone surface becomes lightly distressed and slightly rough. This is also a popular way of creating a non-slip surface to very hard natural stone tiles.

Honed:
A smooth and mat machined surface finish on stone tiles is described as being honed.

Nominal:
A term used to describe only very small variation in the thickness of tiles.

Pillowed:
Another term often used to describe a slightly sloped, and rounded surface, towards the edge of the stone tile. See Cushioned Edge.

Polished:
A high gloss finish, which is created at the quarry as part of the production process. Polished finishes are created using machines which buff the tiles to create an evenly reflective surface.

Porosity:
All natural stones will absorb moisture. A stones susceptibility and ease of which moisture is absorbed is described as its level of porosity. It should be noted that all natural stone tiles have to be sealed. Porosity is reduced substantially by sealing.

Riven:
Uneven surface finish usually found on flagstones, exterior paving, and most commonly on slate. The splitting of layers of hard stone sediment to create tiles will often occur unevenly. The result is a natural surface which has not been machined smooth.

Rustic:
Similar to “antique”. General term used to describe an overall aged appearance of stone tiles which are either natural in appearance, or manufacture to look worn.

Sandblasted:
Also know as shot-blasted. Process where sand is sprayed at very high speed onto the surface of stone, usually to generate a non-slip, or rough finish.

Tumbled:
A common method of ageing stone. Tumbling stone creates an uneven, natural looking rounded edge, as well as a textured surface.

Unfilled:
When travertine is cut into tiles it creates pits and holes in the surface of the stone where natural air pockets have been exposed. Unfilled travertine is often part filled during the fitting process with grout. The resulting surface finish is not as smooth as factory filled tiles. Instead a natural looking textured finish is achieved.

Vein Cut:
The opposite of cross cut. This terms usually refers to travertine which has been cut vertically as opposed to the more common horizontal method. By cutting in the same direction as the layers of sediment, lines of different coloured stone are visible.