Flagstone (flag) is a generic flat

stone In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical composition, and the way in which it is formed. Rocks ...

, sometimes cut in regular rectangular or square shape and usually used for paving slabs or walkways, patios, flooring, fences and roofing. It may be used for memorials,

headstone A gravestone or tombstone is a marker, usually stone, that is placed over a grave. A marker set at the head of the grave may be called a headstone. An especially old or elaborate stone slab may be called a funeral stele, stela, or slab. The u ...

s, facades and other construction. The name derives from

Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman Conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English pe ...

''flagge'' meaning ''turf'', perhaps from

Old Norse Old Norse, also referred to as Old Nordic or Old Scandinavian, was a stage of development of North Germanic languages, North Germanic dialects before their final divergence into separate Nordic languages. Old Norse was spoken by inhabitants ...

''flaga'' meaning ''slab'' or ''chip''. Westray House

Flagstone is a

sedimentary rock Sedimentary rocks are types of rock (geology), rock formed by the cementation (geology), cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or de ...

that is split into layers along bedding planes. Flagstone is usually a form of a

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

composed of

feldspar Feldspar ( ; sometimes spelled felspar) is a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagiocl ...

and

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

and is arenaceous in grain size (0.16 mm – 2 mm in diameter). The material that binds flagstone is usually composed of

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant f ...

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

, or

iron oxide An iron oxide is a chemical compound composed of iron and oxygen. Several iron oxides are recognized. Often they are non-stoichiometric. Ferric oxyhydroxides are a related class of compounds, perhaps the best known of which is rust. Iron ...

. The rock color usually comes from these cementing materials. Typical flagstone colors are red, blue, and buff, though exotic colors exist. Flagstone is

quarried A quarry is a type of open-pit mining, open-pit mine in which dimension stone, rock (geology), rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some juri ...

in places with bedded sedimentary rocks with

fissile In nuclear engineering, fissile material is material that can undergo nuclear fission when struck by a neutron of low energy. A self-sustaining thermal Nuclear chain reaction#Fission chain reaction, chain reaction can only be achieved with fissil ...

bedding planes. Cloister of the University of Bergamo

Around the thirteenth century, the ceilings, walls and floors in European architecture became more ornate. Anglo-Saxons in particular used flagstones as flooring materials in the interior rooms of

castle A castle is a type of fortification, fortified structure built during the Middle Ages predominantly by the nobility or royalty and by Military order (monastic society), military orders. Scholars usually consider a ''castle'' to be the private ...

s and other structures.Williams, Henry Smith (1910).
A history of science, Volume 9
', p. 154. Harper Brothers, New York and London.

Lindisfarne Castle Lindisfarne Castle is a 16th-century castle located on Lindisfarne, Holy Island, near Berwick-upon-Tweed, Northumberland, England, much altered by Sir Edwin Lutyens in 1901. The island is accessible from the mainland at low tide by means of a ca ...

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

and

Muchalls Castle Muchalls Castle stands overlooking the North Sea in the countryside of Kincardine and Mearns, Aberdeenshire, Scotland. The lower course is a well-preserved Romanesque, double-groined 13th-century tower house structure, built by the Frasers o ...

(14th century) in

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

are among many examples of buildings with surviving flagstone floors. Flagstone shingles are a traditional roofing material, and are a type of

roof shingle A roof’s shingles are a roof covering consisting of individual overlapping elements. These elements are typically flat, rectangular shapes laid in courses from the bottom edge of the roof up, with each successive course overlapping the joint ...

commonly used in the

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

, where they are laid dry – often held in place with pegs or hooks. In the

Aosta Valley The Aosta Valley ( ; ; ; or ), officially the Autonomous Region of Aosta Valley, is a mountainous Regions of Italy#Autonomous regions with special statute, autonomous region in northwestern Italy. It is bordered by Auvergne-Rhône-Alpes, Fr ...

, Italy, buildings in historical areas are required to be covered in stone shingles.

References

{{Stonemasonry Building stone Pavements Types of wall Garden features Sandstone Stone (material)

See also

References