Ailsa Craig, a tiny uninhabited island 10 miles off Scotland’s southwest coast, holds the secret to every curling stone that has graced an Olympic ice sheet.
The Granite of Ailsa Craig
The island stands about 1,110 feet high and 2 miles in circumference. It is believed to have formed from volcanic activity millions of years ago, and the Scottish Geology Trust notes it is composed “almost entirely of microgranite,” whose “essentially unflawed nature” makes it ideal for curling stones.
Key to the sport are cold and collisions: teams push stones on ice toward a scoring zone and use brooms to influence the path. Granite that cracks easily is useless, which is why Kays Curling’s co‑owner Jim English says, “It’s not just a case of landing a boat and then looking for granite. There’s a particular type of granite we’re looking for,” and adds, “We look for ones that have got really tight surface pattern.”
The common green granite forms most of the stone, including the “striking band” around the middle. The blue hone granite is essentially waterproof, making it perfect for the running surface. The blue hone is glued in place, and the handle is attached.
Harvesting the Stone
Kays can go years between harvests. The common green “falls off naturally, so we just pick from the site,” Ricky English, operations manager at Kays and Jim’s son, explains. Those selections weigh between 6 and 10 tons.
The blue hone requires dislodging from the cliff face. Engineers drill and insert a gas charge to break the rock along its natural cracks. Those boulders are under 2 tons, so higher quantities can mean fewer harvests.
Boulders are lifted into containers and ferried back to Girvan Harbour. Galloway Granite slices the boulders and cuts round “cheeses” from them, then sends them back to Kays.
Building the Stone
A hole is drilled through the center of the stone, which weighs on average 42 lbs. On a “double insert” — blue hone is attached to both sides, and the handle can screw in to either side — the stone costs 750 pounds or $990. A set of 16 costs 12,000 pounds or $15,860. The single‑insert stone costs 704 pounds or $930.
The granite itself has got elasticity properties in it,” said Ricky English. In a collision, energy is both absorbed and released, “so the stone doesn’t split,” he added.
Protecting the Island
Steps are taken on the island to protect a large colony of Gannets and some gray seals. Rat traps are set to ensure that boats from the mainland — the trip takes just over an hour — don’t reintroduce rodents to the island.
Kays Curling’s Olympic Legacy
Founded in 1851, Kays produces the stones from its shop in the town of Mauchline near Ayr. The company has made all the curling stones for the Milan Cortina Winter Games and has a history with the Olympics dating back to the first winter edition in 1924 in Chamonix, France. The curling competition at those games was long thought to have been an exhibition event but eventually was confirmed as official. Kays has continued to make stones for the games since curling returned as a medal sport in Nagano 1998.
“We can argue that it’s probably won every gold, silver and bronze medal since the sport became a medal sport back in 1998,” said English.
The company holds the only license to harvest granite from Ailsa Craig, which is owned by Lord David Thomas Kennedy, 9th Marquess of Ailsa.
Kays produces 1,800 to 2,000 stones per year. Canada is its biggest market, while China, Japan and South Korea are increasing their orders. “The market in Asia seems to be growing quite a bit,” Ricky English said. “The 2022 Olympics (in Beijing) has maybe just gave it that wee push over there.”
Kays has also sent stones to less‑obvious curling spots like Qatar and Antarctica, where a travel company was using curling as part of a “luxury experience.”
Curling’s Growing Popularity
Scottish Curling traces the sport’s local roots back to 1540 in Paisley Abbey. Centuries later, curling is about to launch its first professional league, after the Milan Cortina Winter Olympics. The Rock League will feature events in the United States, Canada and Europe.
Key Takeaways
- Ailsa Craig’s microgranite is the sole source of Olympic‑grade curling stones.
- Kays Curling’s meticulous harvesting and assembly process ensures durability and precision.
- The company’s Olympic legacy spans from 1924 to the upcoming 2026 Milan Cortina Games.
The world’s finest curling stones are a product of a remote Scottish island, a centuries‑old company, and a tradition that continues to grow on the ice.
