Question: where do curling stones come from in scotland
Answer: Ailsa Craig ( / ˈeɪlsə / ; Scottish Gaelic : Creag Ealasaid ) is an island of 99 hectares ( 240 acres ) in the outer Firth of Clyde , 16 kilometres ( 10 miles ) west of mainland Scotland , upon which blue hone granite has long been quarried to make curling stones .