Silver Weapons

[Tim the Enchanter]

I think that in the case of Voldemort's shield, the dagger, and the sword, JKR isn't meaning that they are MADE from silver, but rather that they are a silver COLOUR.

The sword at least is canonically silver. Griphook has a rant in DH in which he explains how Goblin silver is essentially indestructible and imbibes whatever makes it stronger.

But Tim, I know you tend to favor 'gritty' over 'whimsical', so I think as long as you can explain favoring steel over silver in your stories, I think you can make it work.

I like whimsy. But as you probably deduced grittiness is the better mindset if you want to design a proper weapon.

As I said, there may be magical reasons why goblins choose silver. Perhaps the folklore is right, and it’s possible to drive off ghosts, fairies, witches, goblins and other malevolent supernatural creatures with “cold iron”.

Perhaps the anti-arcane qualities of iron make it difficult to forge with magic. Conversely, silver's good electrical conductivity might also lend to easy charming. The strengthening/sharpening spells added to the metal would probably be more important than the actual physical qualities of the metal.

Steel is magnetic which is rather a poor quality to have in a magical sword if your enemy can hold up a magnet and get the weapon from you.

Bringing a magnet to a sword fight is an excellent way to get yourself killed.

Tim the Enchanter