Arkenstone

[Nerdanel]

Well. I finished reading the Hobbit today. I liked it very much, and I've read through some of the threads in this forum, but I have found very little about the Arkenstone. That wonderful, strange diamond was one thing that got stuck in my head while reading the book.

Where does it come from? Is there some information about it in other Tolkien-books? What were it's powers?

The thing that came across my mind was that it'd be a silmaril.. Because of the shine it had and the powers. But I understand that that is a impossible and rather stupid thought, since one silmaril found it's place in the heart of the earth. I don't believe the dwarves digged that deep..