Curling Stones Come from Two Quarries in the World

Caitlin Dempsey


Curling is one of those oddly mesmerizing sports I tend to only watch when the Winter Olympics is happening. There is something about watching a group of people frantically brushing the ice in front of a slow-moving stone. To be honest, I still don’t quite understand how curling is played, but I do know that it’s intriguing to watch.

What’s also interesting about this Olympic sport is that the stones used in the game come from only two quarries in the world, both located in Great Britain.

The main source of granite used for curling stones comes from Ailsa Craig, a small isle located off the coast of mainland Scotland. Most of the curling stones used in the Olympics and the Paralympics have come from Ailsa Craig.

Kays of Scotland has the exclusive rights to harvest granite from Aisla Craig.

A second quarry is located in Trefor, North Wales has been a source of the granite used for curling stones due to the limited supply of stone in Ailsa Craig.

What are Curling Stones?

A black and white photograph showing men playing curling in Central Park in New York City.
Curling in Central Park, New York City, circa 1900 – 1906. Via Library of Congress, public domain.

Curling stones are solid pieces of granite that have been shaped and smoothed into a round shape with a concave top and bottom. Per the World Curling Federation, curling stones must weigh between 38 and 44 pounds (17.24 and 19.96 kg). A handle is attached to the top of a curling stone.

What Type of Granite is Used for Curling Stones?

For the 2022 Beijing Olympics, all 132 curling stones have been extracted from the quarry on Aisla Craig. The granite available from the isle: Ailsa Craig common green granite, Ailsa Craig blue hone granite, and Ailsa Craig red hone granite, are prized for their tiny molecular structure.

The tight structure of the granite helps to prevent erosion of the curling stone from cold temperatures and from the force of banging into other rocks. The stone is waterproof which prevents small bits of ice seeping into the stone and creating cracks when it refreezes and expands.

Granite on Aisla Craig

Aisla Craig is a Gaelic name that means “fairy rock” in Scotland. The remote isle was formed from a long-extinct volcano. The isle is just off the southwest Scottish coast, about 10 miles (16 kilometers) from the Firth of Clyde mouth.

A Photochrom print of an isle in the Atlantic Ocean taken in 1905.
A Photochrom print of Ailsa Craig, 1905. Photo via Library of Congress, public domain.

Ailsa Craig is comparatively small, with dimensions of 0.75 miles (1.2 kilometers) by 0.5 miles (0.8 kilometers). The height of Ailsa Craig is 1,120 feet (340 meters).

The isle was given the nickname “Paddy’s Milestone” in reference to its strategic location between Scotland and Ireland. In the 1500s the isle served as a safe harbor for Catholics during the Scottish Reformation.

While the island was inhabited for various purposes between the 16th and 19th centuries, there are no inhabitants currently on the island. One of the only surviving structures on the isle is a lighthouse.

An annotated oblique view of an isle off the coast of Scotland.
An oblique view of Ailsa Craig created with Landsat 8 data. Image: NASA, public domain.

Aisla Craig is a Bird Sanctuary

Today the isle is a bird sanctuary managed by the Royal Society for the Protection of Birds under an agreement with the owner of Aisla Craig, the Marquis of Ailsa.

In August of 1847, Queen Victoria, Prince Albert and two of their children were on a tour that passed by Aisla Craig. Queen Victoria remarked about her experience seen the isle, writing in her diary about it “rising nearly 900ft perpendicularly out of the sea … It was covered with thousands & thousands of birds.”

The isle was declared a Site of Special Scientific Interest (SSSI) in 1984.

The gannet colony at Ailsa Craig is Scotland’s third largest. The isle is also an important location for puffins. Guillemots and kittiwakes nest on the isle. Razorbills, herring gulls, shags, fulmars, and black-backed gulls also visit the isle.


Campsie, A. (2022, February 17). Unique Ailsa Craig granite hewn from Firth of Clyde Isle and sent to curlers around the world. The Scotsman.

Carlowicz, M. (2018, March 17). Ailsa Craig. NASA Earth Observatory.

Blake, A. (2006, February 15). Olympic curlers rely on Welsh quarry’s rock. WalesOnline.

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About the author
Caitlin Dempsey
Caitlin Dempsey is the editor of Geography Realm and holds a master's degree in Geography from UCLA as well as a Master of Library and Information Science (MLIS) from SJSU.

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