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[Harry Potter] Could Voldemort have made anything a horcrux? Like Hogwarts Castle or a mountain?

So Voldemort can turn a ring, a locket, a cup, a diary, a diadem, a snake and a boy (even if inadvertently) into a horcrux..


But what about something that’s got a little more lasting power?  Like a mountain for instance?  Almost guaranteed to live on forever there…

Or the Castle?  I know it’s incredibly magical, but so was everything else that he turned in a horcrux, so I’m not sure if that should automatically negate it.
gpt
sure but consider that there for sure a lot of unknown factors about the process. For example, the diary proves that the process hardens any material used, but how much? is that hardening consistent or is it effected by how magical something already is or its size or its other properties? 

Like, imagine that he made a mountain a horcrux and the hardening is constant but only a small amount of damage is required to "destroy" the horcrux. Everyone knows there is something wrong, that mountain started spawning monsters and stopped eroding so now a piece of black marble the size of a mountain is just sitting on the English country side. Harry finds out that it is a horcrux and destroys it with a basilisk fang thrown out a car window because he only needed to make a scratch.