Dean's Amulet

Dean's Amulet, also known as the Samulet by fans, is a piece of jewelry that Dean wore from the Pilot to Good God Y'All and was last seen in Dark Side of The Moon.

History
An 8-year old Sam got the necklace from Bobby, intending to give it as a gift to John for Christmas. However when John didn't turn up, Sam gave it to Dean, who since then always wore it.

In Good God, Y'All, Castiel, who was searching for God, turned up and informed Dean that the the amulet that he wore was an indicator that could lead them to God; according to him, the head piece would glow hot in the presence of God. Dean handed him the amulet, albeit reluctantly, noting that he felt "naked" without it.

After the brothers returned from Heaven in Dark Side of the Moon, Castiel came back to return the necklace, stating that it was "useless". Dean, possibly disillusioned by how all his brother's "happy memories" were ones where he was away from him, dumped the amulet into a wastebasket on his way out of the motel.

Trivia

 * Since the amulet was disposed in Dark Side of the Moon, many fans clamoured for its return. Some speculated that the amulet may resurface later on when the brothers' relationship returned to how it was before the Apocalypse. However, it has never been confirmed by any of the writers, cast or crew.