Rock
Sarsen
Sarsen taşı
The giant stones of Stonehenge: boulders of silica-hardened sandstone scattered over the chalk downs of southern England.
Also known as: Sarsen stone · Grey Wethers · Saracen stone
- Popularly: Natural stone (building and decor)
In short
Sarsens are blocks of silica-cemented sandstone found widely across southern England, especially on Salisbury Plain and the Marlborough Downs in Wiltshire and in Kent. They are the remains of a hard crust (silcrete) that once covered much of southern England. The uprights of Stonehenge's outer circle, its great trilithons and the Avebury stone circle are made of them.
Photos
How does it form?
Sarsens are the remains of a hard crust called silcrete that once covered much of southern England. It is thought to have formed between the Neogene and the Quaternary, when Late Paleocene sands of the Lambeth Group were leached by acidic waters and cemented with silica. The silica filled the spaces between the sand grains and turned them into a very hard rock.
Later the soft sediments around it were worn away. The hard silcrete crust broke up, leaving large blocks scattered over the surface and valleys of the chalk downs. These blocks are what remain from the period after the last ice age.
What is it used for?
- Prehistoric monuments: The uprights of Stonehenge’s outer circle, the lintels on top and the great central trilithons are sarsen. The circle was raised between 2600 and 2400 BC. Avebury and many other megalithic monuments in southern England are also built of sarsen.
- Building stone: It was once broken up with fire, and later with explosives, for walls. Its durability made it a favourite for steps and kerbstones.
Where does the name come from?
The origin of the name is uncertain. The most common explanation is that it is a Wiltshire dialect shortening of “Saracen stone”; in the Middle Ages “Saracen” was used for Muslims and, by extension, for anything non-Christian. Another view derives it from the Old English sār-stān, “troublesome stone”.
Where is it found?
Sarsens are most common in Wiltshire, on Salisbury Plain and the Marlborough Downs. The finest group in England is the Grey Wethers on Fyfield Down. Kent also has many sarsens around the Medway megaliths, and smaller numbers occur in Berkshire, Essex, Oxfordshire, Dorset and Hampshire.
What determines its value?
Sarsen is not an ideal building stone: it is so hard that it was broken up with fire, and later with explosives, before it could be used. Its durability still made it a favourite for steps and kerbstones. Today its real value is historical and scientific: monuments such as Stonehenge and Avebury and natural spreads of sarsens are protected.
This information is educational, not buying, selling or investment advice. Value varies enormously with quality and treatment.
How to recognise it
- 1
Rounded, light grey boulders lying singly or in groups on the surface of chalk downland.
- 2
Very hard: the quartz grains are bound by a cement that is itself silica, so a steel knife will not scratch it.
- 3
Their surfaces are often covered in lichen, and from a distance they can look like a flock of sheep.
Myths and misconceptions
MythAll the stones of Stonehenge were brought from Wales.
FactOnly the smaller “bluestones” (dolerite, tuff, rhyolite and sandstone) came from Wales, from the Preseli hills about 230 km away. The great sarsens were brought from West Woods, only about 25 km to the north.
Did you know?
The sarsens on Fyfield Down are called the Grey Wethers because from afar they look like a flock of sheep; the name appears in a diary as early as 1644.
A recumbent sarsen with grooves on Fyfield Down is interpreted as a prehistoric polishing stone where stone axes were sharpened.
The 18th-century writer William Stukeley complained that houses built of sarsen were always damp in winter and rotted the furniture.
Where is it found?
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- West Woods, near Marlborough, Wiltshire, England · Major depositChemical analysis published in 2020 showed that most of Stonehenge's great sarsens came from here, about 25 km north of the monument.
- Fyfield Down (the Grey Wethers), Wiltshire, England · Major depositThe finest assemblage of sarsens in England, called the Grey Wethers because from afar they look like a flock of sheep. A protected geological and biological site.
- Avebury, Wiltshire, England · Historic sourceThe Avebury stone circle is built of sarsens; some of the stones were later broken up for building.
- Kit's Coty House, near Aylesford, Kent, England · Known localityOne of the Medway megaliths in Kent; sarsens lie around these Early Neolithic tomb monuments.
Locations are approximate to protect sites. Red dots mark places in Türkiye. Open in the big map →
Frequently asked questions
What is sarsen?
Sarsens are blocks of silica-cemented sandstone found widely across southern England, especially on Salisbury Plain and the Marlborough Downs in Wiltshire and in Kent. They are the remains of a hard crust (silcrete) that once covered much of southern England. The uprights of Stonehenge's outer circle, its great trilithons and the Avebury stone circle are made of them.
Where did the sarsens of Stonehenge come from?
A study published in July 2020 showed that most of Stonehenge's great sarsens came from West Woods, about 25 km north of the monument. The researchers compared the chemistry of a core taken from one of the stones in 1958 with 20 sarsen sites around the country.
What is sarsen used for?
Prehistoric monuments: The uprights of Stonehenge's outer circle, the lintels on top and the great central trilithons are sarsen. The circle was raised between 2600 and 2400 BC. Avebury and many other megalithic monuments in southern England are also built of sarsen. Building stone: It was once broken up with fire, and later with explosives, for walls. Its durability made it a favourite for steps and kerbstones.
How hard is sarsen?
It has a hardness of 6–7 on the Mohs scale. It can scratch glass; a steel knife scratches it only with difficulty. Its specific gravity is 2.2–2.8 g/cm³.
Where is sarsen found?
Its best-known localities: West Woods, near Marlborough, Wiltshire, England; Fyfield Down (the Grey Wethers), Wiltshire, England; Avebury, Wiltshire, England; Kit's Coty House, near Aylesford, Kent, England.
How can you tell if sarsen is real?
Rounded, light grey boulders lying singly or in groups on the surface of chalk downland. Very hard: the quartz grains are bound by a cement that is itself silica, so a steel knife will not scratch it. Their surfaces are often covered in lichen, and from a distance they can look like a flock of sheep.
Is sarsen valuable?
On the “street to diamond” value ladder it sits on step 3 of nine: Building and industrial stone. Sarsen is not an ideal building stone: it is so hard that it was broken up with fire, and later with explosives, before it could be used. Its durability still made it a favourite for steps and kerbstones. Today its real value is historical and scientific: monuments such as Stonehenge and Avebury and natural spreads of sarsens are protected.
Sources
- Sarsen · Wikipedia
- Sarsen · Vikipedi
- Stonehenge · Wikipedia
- West Woods · Wikipedia
- Fyfield Down · Wikipedia
- Avebury · Wikipedia
- Kit's Coty House · Wikipedia
- Sandstone · Encyclopaedia Britannica
- Common rock densities · chemeurope.com (from Wikipedia, GFDL)
External links
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