Art: Maglor's Silmaril

And it is told of Maglor that he could not endure the pain with which the Silmaril tormented him; and he cast it at last into the Sea, and thereafter he wandered ever upon the shores, singing in pain and regret beside the waves.
(J.R.R. Tolkien, The Silmarillion, Chapter 24: Of the Voyage of Eärendil and the War of Wrath)