Mithril Armor?

[doug*platypus]

I think that the "light but strong" aspect of mithril has led a lot of people, myself included, to speculate that it might be aluminium. However, my own corslet of forged Coke can tabs (great call, Aluminium Saucepan Man!) has never been of much use in defending me from spear thrusts.

And as for Ithildin, the substance which the west door of Moria was decorated with, I don't think that aluminium can really do that. I think that mithril was entirely invented, and that its incredible rarity was a way for Tolkien to explain why we don't see it around today. I can't recall when the Periodic Table reached its current form, but doubtless Tolkien would not have known about it anyway. If he had seen the remarkable completeness and simplicity of the table, he might have canned the idea of mithril altogether.