'Jewel of the world' may seem rather a grand name for a little-known scion of a minor branch of the Númenórean royal family, but in fact the name appears to have considerably more significant origins, referring to Eärendil the Mariner. Eärendil was the name chosen by the Mariner's father Tuor, but his mother Idril gave him another name: Ardamírë (or Ardamir in Sindarin), 'jewel of the world', which was later revealed to be a prophetic reference to the shining Silmaril borne by Eärendil in the skies of the West. Ardamir of Númenor seems to have taken his name from his illustrious ancestor Eärendil. (This account of Eärendil's mother-name is not found in canonical sources; it appears in The Shibboleth of Fëanor in volume XII of The History of Middle-earth.)