Treeaddict
Treehouser
Watching a YouTube documentary and then internet surfed to find that a Scottish company names Kay’s makes the only Olympic regulatory stones. Looks like one of these curling stones costs between $500-$800 each. Wow! They take the granite from an uninhabited island off their coast and bring it back to their factory to make the stones out of 2 types of granite - a granite sandwich. I didn’t want to feel like I was writing a paper so no references. All is googlable though.