Is the Arkenstone a Silmaril?

[cassiopeia]

Forgive me if this is in the wrong forum, it encompasses The Silmarillion and The Hobbit, so I decided to place it here. I found this question on another board and found it interesting so here it is: Is the arkenstone Maedhros' lost silmaril? We know that Maedhros cast himself into a chasm with the silmaril and that the dwarves found the arkenstone in Erebor. The arkenstone and silmaril are similar in apearance. My main objection to them being the same object is the fact that the arkenstone was eventually buried with Thorin. Would the elves (or any race) let a silmaril be buried? I would like to know peoples thoughts on this, I find it quite facinating.