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 [=are from the distant past; are very out of date]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.
(..) why not keep it secure in your own vault? The Tesseract is already on Asgard. It is not wise to keep two Infinity Stones so close together. That's very wise. I can assure you, it will be absolutely safe here, in my collection. (..)2013 Thor: The Dark World
(..) Mother told them to us as children. Their leader Malekith made a weapon out of that darkness and it was called the Aether. While the other relics often appear as stones the Aether is fluid and everchanging. It changes matter into dark matter. It seeks out host bodies, (..)2013 Thor: The Dark World