Ithildin was a type of specially crafted Mithril that only the most experienced craftsmen of the Noldor could learn how to make and pass on to others. It was enchanted so that it only appears in moonlight or starlight, and could be enchanted further so that it would never appear except on a specific phase of the moon on a specific night, or only when certain words were uttered in its presence. It was used also on the Doors of Durin in the Second Age.
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.
Curvy leaf shaped earrings made with silver paint over semi-transparent black resin. Its color changes depending upon the light. Matte on daylight, shiny on nightlight.