Tolkien mentioned through quick parts of LOTR that only one dragon's fire might
be able to melt the One Ring. My interpretation from Tolkien's vague hints at
this is, it's impossible to destroy the Ring anywhere else but Mt. Doom.
If somehow, by chance, the Ring was never found by Deagol or was hidden in an
impossible to reach location, like lava;
My theory is that two things might happen in this event...
1. The Ring would never be found, and Sauron would eventually gain in strength
without the Ring. Middle Earth would then be destroyed because there
would never be "The Fellowship of the Ring".
2. If the Ring were able to willfully find it's way out of the lava or
impossible to reach location, it would most likely only be found by the enemy.
Because that's what the Ring would want. But that's if you believe more
in the power of the Ring from the movies.
In the books, Ring Wraiths would probably be able to reach the Ring, if they
found it before Sauron created another that
is.
----Still trying to learn some Hobbit sense.----
