Enerdhil

Enerdhil was a possibly mythical jewel-smith of Gondolin.

He was a lover of all things that grew green in the world and ever desired to see the sunlight through the leaves of the trees, and so he created a great green gem which was beloved by all who looked through it. He apparently gave it Idril who in turn gave it to her son Eärendil and from there it is said that it went over the sea with Enerdhil.

In other versions of the legendarium, the Elessar gem was made by Celebrimbor, son of Curufin of Eregion.