Earendil's star

[Ibrîniðilpathânezel]

I was always under the impression that in order for Yavanna to revive the Trees, Feanor had to willingly surrender the Silmaril and break it. He was the one who invented the substance of which they were made, and though the Valar might break it, their methods might have destroyed the jewel rather than open it to release the light. In this, I think it is similar to Sauron's Ring. He made it, and he might have unmade it without destroying it, but the only way in which another could release or nullify its power would be to destroy it. Moreover, I do believe that Tolkien wanted the aspect of a willing sacrifice to be part of it. When Feanor refused to make that sacrifice, no one else could do so, for they had not made the jewels and thus it was not their sacrifice to make. In any case, by the time Earendil arrived, the point was moot, as the Sun and the Moon had already been fashioned from the last fruit of the Trees and a new age of the world begun.