Du är felaktig. Inte någon vulkan skulle göra, inte heller skulle drakefire förstöra One Ring. Mount Doom hade magisk betydelse, sedan ringen fanns där.
‘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.
There is only one way: to find the Cracks of Doom in the depths of Orodruin, the Fire-mountain, and cast the Ring in there, if you really wish to destroy it, to put it beyond the grasp of the Enemy for ever.’
LotR, tidigare skuggor
Jag tvivlar också på att dvärgarna någonsin drog ner i magma. Det finns ingen indikation jag är medveten om att de gjorde det. Gandalf föll i Moria, som var den största dvärgens största och antika fördjupning, och Gandalf föll vidare än dvärgarna hade delvat, och han rapporterade inte det.
‘Name him not! ’ said Gandalf, and for a moment it seemed that a cloud of pain passed over his face, and he sat silent, looking old as death. ‘Long time I fell,’ he said at last, slowly, as if thinking back with difficulty. ‘Long I fell, and he fell with me. His fire was about me. I was burned. Then we plunged into the deep water and all was dark. Cold it was as the tide of death: almost it froze my heart.’
‘Deep is the abyss that is spanned by Durin's Bridge, and none has measured it,’ said Gimli.
‘Yet it has a bottom, beyond light and knowledge,’ said Gandalf. ‘Thither I came at last, to the uttermost foundations of stone. He was with me still. His fire was quenched, but now he was a thing of slime, stronger than a strangling snake.
‘We fought far under the living earth, where time is not counted. Ever he clutched me, and ever I hewed him, till at last he fled into dark tunnels. They were not made by Durin's folk, Gimli son of Gloin. Far, far below the deepest delving of the Dwarves, the world is gnawed by nameless things. Even Sauron knows them not. They are older than he.
(LotR, The White Rider)
Vi har ingen anledning att tro att de andra dvärghushållen som är kända i väst, i Iron Hills och Blue Mountains, hade större sannolikhet att ha magma under dem på något uppnåeligt djup.
Dessutom finns det inga andra kända vulkaner i Middle Earth; de skulle behöva upptäcka dem. Oavsett vulkaner som existerade var nästan säkert i söder och öst, dominerades också av riket av Sauron.