Why were the Silmarils so important?

[Voralphion]

As to the silmarils having any power, it is said that the elf colony at Tol Sirion where Earendil left from was made green by the power of the Silmaril of Elwing that brought healing. Although this was attributed to the Elessar in another version of the story, the silmaril did have healing powers.

[dkhyrosha]

I think it was a combination of the killing of Finwe, the pride of Feanor, and the fact that the light of the jewels was all that was left of the Trees

[bilbo_baggins]

Maybe not so much the loss of the light of the Trees...

Weren't the Trees detroyed and then the Valar made an appeal to Feanor to give of his Silmarilli to return life to the trees? Feanor turned them down and returned home, only to find that his precious jewels had been lost. Then Feanor went a rampage of vengeance and retrieval. Feanor cared only for his creation, and he was the main instigator of vengeful thoughts among the Elves of Tol Sirion.

That's just my thoughts,

[Frodo2968thewhite]

it is true that the Elves cherished the jewels for the fact that they hold the last light of the two trees, but Fate also must have played a huge role in it...The way I see it, everything that happens 'in any world' is for a reason. I do believe that Arda once existed, and that Iluvatar must have had a plan for the Silmarils. It's not just the physical power that they beheld that is amazing, but also the spiritual aspect of it. Let us go to the second prophecy of Mandos...

Thereafter shall the Silmarils be recovered out of sea and earth and air; for Earendil shall descend and yield up that flame that he hath had in keeping. Then Feanor shall bear the Three and yield their fire to rekindle the Two Trees, and a great light shall come forth; and the Mountains of Valinor shall be levelled, so that the light goes out over all the world. In that light the Gods will again grow young, and the Elves awake and all their dead arise, and the purpose of Iluvatar be fulfilled concerning them. But of Men in that day the prophecy speaks not, save of Turin only, and him it names among the Gods." (The Shaping of Middle Earth - HOME 5)

So from this I conceive the fact that The Silmarils were important because of fate and roles that they have yet to play...