Hamstone is a honey-coloured building stone from Ham Hill, Somerset, England. It is a well-cemented medium to coarse grained limestone characterised by marked bedding planes of clay inclusions and less well-cemented material which weather differentially to give exposed blocks a characteristic furrowed appearance. In origin, Hamstone is a

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

from the

Toarcian The Toarcian is, in the International Commission on Stratigraphy, ICS' geologic timescale, an age (geology), age and stage (stratigraphy), stage in the Early Jurassic, Early or Lower Jurassic. It spans the time between 184.2 Megaannum, Ma (million ...

, or Upper Lias, stage.

History

In the 19th century there were 24 small quarries operating on Ham Hill employing some 200 men. In later Victorian times industrial quarrying expanded significantly, with upwards of 200 small family-run quarries and masonry businesses operating on site.

Modern quarrying

Today hamstone is quarried in only two areas of Ham Hill. The North quarry, run by Ham & Doulting Stone, extracts stone from just beneath the surface and is the longest running hamstone quarry in existence. The Norton or South quarry, run by Harvey Stone, extracts its stone from some 20–30 metres below the surface. This quarry was formed by the re-opening of workings that were abandoned in the 1930s. Hamstone House was built with the last significant supply of hamstone from the quarries before their closure. Both quarries are owned by the

Duchy of Cornwall A duchy, also called a dukedom, is a country, territory, fief, or domain ruled by a duke or duchess, a ruler hierarchically second to the king or queen in Western European tradition. There once existed an important difference between "sovereign ...

. A study by South Somerset District Council’s Area Conservation Officer noted that the stone of the South quarry is yellower in colour, less hard and less durable than the greyer North quarry hamstone. North quarry stone is primarily used by local stonemasons for the repair of external features in historic buildings, such as mullion windows and ashlars stonework as well as for new developments in conservation areas.

Style and usage

Described by

Simon Jenkins Sir Simon David Jenkins FLSW (born 10 June 1943) is a British author, a newspaper columnist and editor. He was editor of the ''Evening Standard'' from 1976 to 1978 and of ''The Times'' from 1990 to 1992. Jenkins chaired the National Trust f ...

as "the loveliest building material in England", hamstone is soft enough to be cut to make decorative features such as doorway arches and bell openings in church towers such as at the Church of St Mary at Chedzoy, Somerset. The attractive colour also contributes to its being chosen by masons and architects for more than 1000 years for adorning the buildings in the countryside of surrounding

Somerset Somerset ( , ), Archaism, archaically Somersetshire ( , , ) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by the Bristol Channel, Gloucestershire, and Bristol to the north, Wiltshire to the east ...

. Hamstone is featured in the medieval church towers throughout the county, and the town of South Petherton is built largely of the material. Besides being used for building, hamstone was also burnt locally in small kilns for the manufacture of lime, predominantly for use as fertiliser. Some was used for the manufacture of builders' mortar and limewash render, but the results were of poor quality due to the iron content of the stone. At least two lime kilns still exist: one close to the abandoned medieval hamlet of Witcombe, with another close to Norton Quarry.

References

External links

Technical Data Sheet Ham Hill Lower Bed Limestone

SOMERSET BUILDING STONE – A GUIDE
{{Webarchive, url=https://web.archive.org/web/20120331095321/http://www.sanhs.org/Documents/Proc%20Building%20stone.pdf , date=31 March 2012

Mining in Somerset Limestone Building stone Geology of Somerset