‘Your small fire, of course, would not melt even ordinary gold. This
Ring has already passed through it unscathed, and even unheated. But
there is no smith’s forge in this Shire that could change it at all. Not
even the anvils and furnaces of the Dwarves could do that. It has
been said that dragon-fire could melt and consume the Rings of
Power, but there is not now any dragon left on earth in which the
old fire is hot enough; nor was there ever any dragon, not even
Ancalagon the Black, who could have harmed the One Ring, the
Ruling Ring, for that was made by Sauron himself.