Originally Posted by
Feanaro Curufinwe
Mithril.Galvorn i stated to be as hard as steel, but Mithril is explicitly stated to be even harder.
"Mithril! All folk desired it. It could be beaten like copper, and polished like glass; and the Dwarves could make of it a metal, light and yet harder than tempered steel. Its beauty was like to that of common silver, but the beauty of mithril did not tarnish or grow dim."
Value though is a different matter. Mithril is stronger, more useful and beautiful while Galvorn enjoys the fact that only Eol knew how to make it, and thus it's value is increased through it's rarity.