By Bruce Gittings, University of Edinburgh & Michael Cairns, RSGS Collections 

As we celebrate the success of a well-deserved silver medal for the British Olympic curling team comprising the Scots Bruce Mouat, Grant Hardie, Bobby Lammie and Hammy McMillan, with Kyle Waddell as alternate, it is worth also celebrating the central position which Scotland plays in the sport.

Its well-known that the sport has its origins in Scotland, dating back to at least 1540 when the monks of Paisley Abbey are recorded as having played a game whereby they slid stones across the ice. Then there was the Duddingston Curling Society, which framed the rules of the game and counted Rev. John Thomson (known for ‘Jock Tamson’s bairns’) as an early member.

However it is Scottish geology that created the stones used in the Olympic games. Fashioned from not one but two unique forms of micro-granite taken from the island of Ailsa Craig in the Firth of Clyde, which are particularly suited to the sport. This distinctive dome-shaped island-rock lies 10 miles (16 km) off the coast of South Ayrshire and rises sharply from the Firth of Clyde to a height of 340m (1114 feet).

Ailsa Craig, which comes from the Gaelic for 'Fairy Rock', is 1200m (1300 yards) long and 800m (900 yards) wide, with an area of 100 ha (245 acres). It is also known as Paddy's Milestone owing to its position as a landmark en route from Ireland. The island was the heart of an ancient volcano, dating from the first opening of the Atlantic Ocean 60 million years ago, The island is also home to a lighthouse, built in 1883-6 by Thomas Stevenson (1818-87) and his nephew David A. Stevenson (1854 - 1938), and one of the largest gannet colonies in the world

Ailsa Craig is the property of the Marquess of Ailsa, whose family has owned the island since 1560. Kays of Scotland, based in Mauchline (South Ayrshire), hold an exclusive lease to extract granite boulders to make curling stones.

Kays of Scotland have been suppliers of precision-made competition-standard curling stones since 1851, which are now exported around the world. As the rules of the sport developed, Kays were instrumental in setting the standard weight of 40 pounds (18.1 kg) for curling stones, a specification now adopted internationally. They are one of only two manufacturers of curling stones in the world, their competitors are the Canada Curling Stone Co. of Komoka Ontario who use Welsh stone.

Every six or seven years, the company 'harvest' around 2000 tons of the stone to meet their production needs. The stone is not quarried in the traditional sense; there is no blasting or cutting stone from fixed rock faces, rather only loose boulders that have detached through natural processes are taken.

Kays occupied their current site in 1911, moving from their original water-powered mill at Haugh on the north bank of the River Ayr, 1¼ miles (2 km) to the south. They remain a family-owned business that produces up to 2000 stones per year. The company has a skilled workforce and, although extensive use is now made of machinery in the processes of cutting, shaping and polishing the stones, the hand and eye of the expert remains key to the finished product. Each stone is unique, with slightly different characteristics which are learned by top-level players. Kays manufacture stones using a conjunction of two different types of Ailsa Craig granite. The body comprises Common Green Granite, which is tough and particularly resistant to splintering when it hits another stone in play. A hole is cut through this body, to create a doughnut shape, and this hole is filled with a core of dense Blue Hone Granite, known as an Ailsert. It is the base of this core which makes contact with the ice, and it effectively resists abrasion. Typically each stone lasts 25 years, although stones can be refurbished to extend their life.

Kays have supplied curling stones to every Winter Olympic Games since Chamonix in 1924, with the exception of the 2002 event in Salt Lake City.

Bruce’s travels around Scotland inspire entries in The Gazetteer for Scotland www.scottish-places.info.