Silmarils

After Melkor stole Silmarils, one of them was recovered by Beren and Lúthien through great peril and loss. This stone was later taken by Eärendil, the husband of their granddaughter Elwing, to the Valar in the West as a token of repentance. The Valar then set this Silmaril in the sky as a star called Gil-Orestel. The other two gems remained in Morgoth's hands, and were taken from him only at the end of the War of Wrath. Soon afterwards, they were stolen by Fëanor's two sons Maedhros and Maglor. The jewels burned their hands, in refusal of their rights of possession, as they had burned Morgoth's hands many years before. In agony, Maedhros threw himself and his Silmaril into a fiery pit, and Maglor cast his into the sea. The Silmarils remained in all three realms of Arda — in the sky, beneath the earth, and within the sea.