Mirror of Galadriel
On 15 February T.A. 3019, while the Fellowship of the Ring were staying in Lothlórien, she invited Frodo Baggins to look into it. Galadriel could not predict what the mirror would show and did not guarantee that its visions would come to pass.
Samwise Gamgee was also allowed a vision, which turned out to be a choice between returning to the Shire to prevent its destruction by technology or to continue on the quest with his master to prevent Sauron from destroying all of Middle-earth.
This recalls the ancient practice of water scrying or hydromancy: gazing into a shallow pool or bowl for purposes of divination. The Norns of Norse mythology used the Well of Urd as a scrying bowl.[source?]