Most Olympic curling stones come from a single, very specific place: the granite of Ailsa Craig, a small uninhabited island off the west coast of Scotland.

Quick Scoop: Where do Olympic curling stones come from?

The island behind the stones

  • Ailsa Craig is a steep, volcanic plug rising out of the Firth of Clyde, about 15 km off Scotland’s west coast.
  • Its granite formed around 60 million years ago from cooling magma during intense volcanic activity as the North Atlantic opened.
  • The island is uninhabited today and also serves as a protected seabird haven, so granite is harvested only occasionally and with restrictions.

The company that makes them

  • Kays of Scotland (often called Kays Curling), founded in 1851, is the historic maker of these stones.
  • Kays has supplied Olympic curling stones since the early Winter Games and has been the exclusive supplier for the Olympics and World Curling Federation events since the mid‑2000s.
  • The stones are crafted and finished at Kays’ workshop in Mauchline, Ayrshire, after the raw granite is brought from Ailsa Craig to the mainland.

What’s special about the granite?

  • Ailsa Craig’s granite is unusually hard, dense, and finely grained, which makes it resistant to chipping despite repeated high‑speed impacts on ice.
  • Its chemistry is unusual for granite, with low aluminum and rare sodium‑ and iron‑rich minerals that contribute to its toughness and low water absorption.
  • There are two key varieties used:
    • Blue hone : used for the running surface (bottom ring) because it resists pitting and gives consistent glide and curl.
* **Common green** : used for the main body of the stone.

How often is the stone quarried?

  • Granite is taken from Ailsa Craig roughly once a decade in carefully planned operations.
  • The company now mainly collects blocks and boulders that have already broken free, rather than blasting large new faces, both to preserve the island and to comply with environmental protections.

What happens after the rock leaves the island?

  • Large blocks are sliced and cored into rough cylinders on the mainland, then shaped into the familiar “rock” form.
  • Each stone is machined to tight tolerances: typically 38–44 pounds in weight and very specific dimensions, as required by curling’s rules.
  • The running surface is precisely finished and textured so that the stone will grip the ice just enough to “curl” when thrown, rather than sliding straight.

Are all Olympic stones from there?

  • Modern Winter Olympics and World Curling Federation championship events use stones made by Kays from Ailsa Craig granite, by rule and accreditation.
  • Historically, a small amount of granite from another quarry in Wales (Trefor) was also used in some stones, but supply issues and performance factors pushed a shift toward almost exclusive reliance on Ailsa Craig granite.

Why is this a trending topic now?

  • With each Winter Olympics, interest spikes in unusual sporting details—curling stones being a classic example.
  • Recent coverage from major outlets has highlighted:
    • The island’s limited granite reserves and the need to make each harvest last for many years.
* The high cost of a single top‑spec Olympic stone (hundreds of dollars or more per stone, thousands for a full set).

* The almost “mythic” status of Ailsa Craig as the quiet source behind every Olympic curling tournament.

In one line: When people ask “where do Olympic curling stones come from,” the answer is: almost all of them start life as rare, ultra‑tough granite on the tiny Scottish island of Ailsa Craig, then are hand‑crafted into precision stones by Kays of Scotland in Ayrshire.

Information gathered from public forums or data available on the internet and portrayed here.