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 headstone, tombstone, or gravestone is a stele or marker, usually stone, that is placed over a grave. It is traditional for burials in the Christian, Jewish, and Muslim religions, among others. In most cases, it has the deceased's name, da ...

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 p ...

''flagge'' meaning turf, perhaps from

Old Norse Old Norse, Old Nordic, or Old Scandinavian, is 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 of Scandinavia and t ...

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

Flagstone is a

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

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

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

composed of

feldspar Feldspars are 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 ''plagioclase'' (sodium-calcium) feldsp ...

and

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...

and is

arenaceous Arenite ( Latin: ''arena'', "sand") is a sedimentary clastic rock with sand grain size between 0.0625 mm (0.00246 in) and 2 mm (0.08 in) and contain less than 15% matrix. The related adjective is ''arenaceous''. The equivalen ...

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 , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...

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 Iron oxides are chemical compounds composed of iron and oxygen. Several iron oxides are recognized. All are black magnetic solids. Often they are non-stoichiometric. Oxyhydroxides are a related class of compounds, perhaps the best known of whic ...

. The rock color usually comes from these cementing materials. Typical flagstone colors are red, blue, and

buff Buff or BUFF may refer to: People * Buff (surname), a list of people * Buff (nickname), a list of people * Johnny Buff, ring name of American world champion boxer John Lisky (1888–1955) * Buff Bagwell, a ring name of American professional ...

, 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 capable of sustaining a nuclear fission chain reaction. By definition, fissile material can sustain a chain reaction with neutrons of thermal energy. The predominant neutron energy may be typ ...

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 fortified structure built during the Middle Ages predominantly by the nobility or royalty and by military orders. Scholars debate the scope of the word ''castle'', but usually consider it to be the private fortified r ...

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 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 causeway. H ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

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 of ...

(14th century) in

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

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

roof shingle Roof 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 joints below. ...

commonly used in the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

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

Aosta Valley , Valdostan or Valdotainian it, Valdostano (man) it, Valdostana (woman)french: Valdôtain (man)french: Valdôtaine (woman) , population_note = , population_blank1_title = Official languages , population_blank1 = Italian French ...

, 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