Every four years, sports fans tune into the Winter Olympics to watch athletics they don’t normally see anywhere else, including bobsledding, ski jumping, and speed skating. Curling has also become a trending spectator sport. Curling is a strategic winter team sport played on ice, where players slide 42-pound polished granite stones toward a target circle, called the “house." Two teams of four take turns delivering stones, using specialized brooms to sweep the ice in front of the stone to influence its speed and direction. The goal is to have the closest stones to the center compared to the opponent after all the stones are thrown. The granite stones, which weigh between 38 and 44 pounds, come from a small island off Scotland called Ailsa Craig. The island's granite has been specifically used for curling stones because it’s one of the hardest in the world, allowing it to maintain its shape when used on the wet ice surface. The curling stones are made from two different types of granite from the island: blue hone granite and common green granite, to make them easily handle the cold and wet of the ice, as well as to give them the strength to hit other curling stones during play. All of these features come together to make the stones predictable when curling, giving competitors a good reference on how stones will slide, and making the granite from Ailsa Craig ideal for curlers.
