His political ideas are from 'the Stone Age'. [=are from the distant past; are very out of date]
Their lawyer said that he would 'leave no stone unturned' in trying to find more evidence.
The researchers 'left no stone unturned' in their search for the original documents.
(..) Who's Meucci? The Italian-American who invented the telephone, one year before Bell. And this is the reason you've come today? I... I've got a stone in my shoe. A two-bit punk who works for me. The one who thinks he's related to you. A bastard. He's here. Vincent Mancini. He's at the party. (..)1990 The Godfather Part III