although I haven't read the Silmarilian... (too hard for me to get into) that sounds a lot like what I have read about what the book is about xD ...
Doesn't matter if it can destroy it or not, if it blows up the planet then the ring will be tossed through space if it survives. A ring is very very small, the chance that it hits any planet is very very small and it would probably take hundreds if not thousands of years for that to happen if it ever did. Heck it could just as easily fall into a black hole or into a star and get stuck there forever.
But don't you know? The Ring has a will of its own, it will find its way to someone's poket!
Anyway, although the above poster pretty much ended the discussion with a quote from thier friend
. I like to think of the Ring as a Horcrux like in Harry Potter, after all, a portion of Souron's soul is inside the Ring, making it so indestructible and giving it the power to influence/manipulate the people around it. Also, i'm pretty sure at some point or another Mount Doom's fires are refered to as being cursed, which also fits in with the Harry Potter horcruxes and one of the ways to destroy them being with cursed flames