Hamstone is the colloquial name given to stone from Ham Hill, Somerset, England. Hamstone is a Jurassic limestone from the Toarcian, or Upper Lias, stage. It is a well cemented medium to coarse grained limestone characterised by its honey-gold colour and marked bedding planes. The stone contains thin beds of less well cemented material and some small clay inclusions. These areas weather differentially to give weathered hamstone its characteristic furrowed appearance.
In the 19th century there were 24 small quarries operating on the hill employing some 200 men. In later Victorian times industrial quarrying really took off with upwards of 200 small family run quarries and masonry businesses operating on site. Today hamstone is only quarried in two areas on the top of Ham Hill. The North quarry, near the modern stone circle and war memorial, is the longest running hamstone quarry in existence and extracts stone from just beneath the surface, it is quarried by Ham & Doulting Stone. The southern, Norton Quarry extracts its stone from some 20–30 metres below the surface and is quarried by Harvey Stone. This quarry was reopened around 15 years ago, having been the last quarry abandoned in the 1930s due to there being, according to the masons working the hill "no good quality stone left". Both quarries are owned by the Duchy of Cornwall.
Described by Simon Jenkins as "the loveliest building material in England," golden 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. Hamstone is featured in the medieval church towers throughout the county, and the town of South Petherton, for example, is built largely of hamstone.
Besides being used for building, hamstone was also burnt locally in small kilns for the manufacture of lime. This was predominantly for local 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. Mortar made from hamstone invariably failed, often washing away, while limewash would blister and bubble, eventually falling from the wall. At least two lime kilns still exist: one close to the abandoned medieval hamlet of Witcombe, with another close to Norton Quarry
- Haslett, Simon K. (2010). Somerset Landscapes: Geology and landforms. Usk: Blackbarn Books. pp. 81–86. ISBN 9781456416317.
- Ham Hill Country Park -Medieval and Victorian History — Visit South Somerset 
- Ham Hill Country Park — Victorians to More Recent Times — Visit South Somerset 
- Ham Stone - Ham & Doulting Stone Ltd
- Jenkins, Simon (2000). England's Thousand Best Churches. Penguin Books. ISBN 0-14-029795-2.
- "St Mary's, Chedzoy, Somerset". Minerva Stone Conservation. Retrieved 2009-05-18.