Here’s one for you: what do curling and Trump Turnberry have in common?
We’ll give you a clue – you’ll find it in most photographs of the golf courses at the Ayrshire resort.
Nope, it’s not the lighthouse. Instead, it’s the small uninhabited island lying ten miles off the coast: Ailsa Craig.
Instantly recognisable to golfers around the world as part of the magnificent backdrop to the four-time Open Championship host venue, the Ailsa Craig is also hugely significant to Team GB’s Eve Muirhead and her fellow curlers.
That’s because the imposing volcanic plug - also known as “Paddy’s Milestone” for its location halfway between Glasgow and Belfast - is where the vast majority of curling stones start life.
The island is home to rare granite which has a highly-interlocked, finely-grained mineral structure that is free from quartz. It’s these unique properties that makes it perfect for manufacturing curling stones.
Stones made of ordinary granite would crack upon impact with one another. However, the granite harvested from the Ailsa Craig is much more resilient and durable.
Kays Curling Stones is the biggest name in the manufacture of curling stones. Indeed, its stones are the only ones used in competition by The World Curling Federation.
Based in Ayrshire and dating back to 1851, the company has the exclusive rights to harvest three different types of granite from Ailsa Craig - Ailsa Craig Common Green Granite, Ailsa Craig Blue Hone Granite and Ailsa Craig Red Hone Granite - which it then transports back to the Scottish mainland by boat where the raw boulders and stored until they are ready to be transformed into curling stones.
“Over the years our craftsmen have researched the most suitable granites for the various parts of the curling stone,” states the Kays website. “This extensive research proved that Ailsa Craig Blue Hone granite is the most reliable and proven to be the only effective material for the stone’s running edge on today’s modern ice.
“The Ailsa Craig Common Green Granite is used for the body of the stone because its unique structure is more resistant to heat transfer. It copes better with condensation and does not splinter after contact with another stone in play.
“The Blue Hone insert is fitted to the Ailsa Craig Common Green stone body, a technique we have perfected and called ‘Ailserts’.”
And to think you thought the Ailsa Craig was just a pretty island in the background of pictures of Turnberry!