“I suppose I shall be going home soon?“ Bilbo sleepily asked. “As soon as you like,” said the wizard.
Actually it was some days before Bilbo really set out. They buried Thorin deep beneath the mountain, and Bard laid the Arkenstone upon his breast.
“There let it lie till the Mountain falls!” he said. “May it bring good fortune to all his folk that dwell here after!”
Upon his tomb the Elvenking then laid Orcrist, the Elvish sword that had been taken from Thorin in captivity. It is said in songs that it gleamed ever in the dark if foes approached, and the fortress of the dwarves could not ever be taken by surprise.
~ JRR Tolkien, The Hobbit, p 350