I think they are like the heart and soul of the elves, and without them they wouldn't be able to hold off against Morgoth's attacks. Don't take my word for it, just my two cents.
The Silmarils also called the Jewels of Fëanor were the gems crafted by Fëanor from the last essence of the two trees of Valinor; Laurelin and Telperion. They were among the most prized of all the wonders crafted by the elves and were coveted by many. It was said that the fate of Arda was woven about the Silmarils. They were named for and crafted of the hard crystalline substance silima, and contained some of the light from the Two Trees of Valinor made by Yavanna and Nienna-named Telperion the Silver, and Laurelin the Gold. After Fëanor was exiled to Formenos, the Silmarils were stored in a chamber of iron.
They are a pretty big deal.
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Sing my world into being, Ainur. The universe needs your power!
I just read all about the year of lamps, the years of trees, and the years of the sun. I also read about the Silmarils. Prety heavy stuff. They are awesome things though!