[Eönwë]

I was wondering, is the Arkenstone the Silmaril that fell into the Earth? After the mountains shifted and Beleriand went, did a Silmaril come up in the heart of a mountain, encased in stone, only to be carved back by a dwarf? This would explain everything. I'm not sure about dates and if this theory works (because the War of Wrath was before the Silmarils were recovered, though only just, I think). Does anyone know the answer?