Shards of limestone or broken pottery used for sketching by an Egyptian and Greek artists. The Greek word ostracon literally meant oystershell.The Greeks wrote names on fragments of broken pottery or tile as ballots when voting to exile someone who represented a danger to the state. An ancient anecdote about such ostraca (the plural form): Aristides the Just was once handed a potsherd by an illiterate fellow citizen, who asked him to scratch "Aristides" on it. As Aristides started to write, he asked the man, "What's so bad about Aristides?" "I'm just tired of hearing him called 'the Just,'" the fellow replied.