While we're enjoying the Winter Olympics, obligatory mention of that time I was lucky enough to spend a couple of days on Ailsa Craig..
All curling stones are quarried from here (the good ones anyway) the current company extracts granite about once a decade, Ruth Ailsing went out with them a few years ago and made this really interesting video on it -https://youtu.be/lTjOoeR0iFY
It's a short boat trip from Girvan and definitely worth it if you're in the area