§ Of Fëanor and the Unchaining of Melkor The Silmarillion

An his love he gave thereafter to his son; and Fëanor grew swiftly, as if a secret fire were kindled within him. He was tall, and fair of face, and masterful, his eyes piercingly bright and his hair raven-dark; in the pursuit of all his purposes eager and steadfast. Few ever changed his courses by counsel, none by force. He became of all the Noldor, then or after, the most subtle in mind and the most skilled in hand. In his youth, bettering the work of Rúmil, he devised those letters which bear his name, and which the Eldar used ever after; and he it was who, first of the Noldor, discovered how gems greater and brighter than those of the earth might be made with skill. The first gems that Fëanor made were white and colourless, but being set under starlight they would blaze with blue and silver fires brighter than Helluin; and other crystals he made also, wherein things far away could be seen small but clear, as with the eyes of the eagles of Manwë. Seldom were the hands and mind of Fëanor at rest.