Ithildin
From Tolkien Gateway

The Doors of Moria by Donato Giancola.
Ithildin was a substance made by the Elves out of the metal mithril and used by the Gwaith-i-Mírdain in constructions such as gateways. Ithildin could only be seen by the reflected light of the Moon and stars, and even then remained hidden until a "magic" word was said. The designs on the Doors of Durin were made from this substance.[1]
Etymology[edit | edit source]
In the legendarium, Gandalf translated ithildin as "starmoon".[1]
Tolkien stated that ithildin is a Sindarin name, meaning "moon-star(light"), "moonlight" or "starlight". The word contains the elements Ithil ("moon") + tin/tîn ("spark; star; twinkle of stars"). He noted that the correct Sindarin form should be ithildim.[2]
References
- ↑ 1.0 1.1 J.R.R. Tolkien, The Lord of the Rings, The Fellowship of the Ring, "A Journey in the Dark", p. 317
- ↑ J.R.R. Tolkien, "Words, Phrases and Passages in Various Tongues in The Lord of the Rings", in Parma Eldalamberon XVII (edited by Christopher Gilson), pp. 39, 66