Truesilver
From Tolkien Gateway
Truesilver was a Mannish name for the uniquely valuable metal also known as Moria-silver, because it could only be found in the Mines of Moria, at least in the Third Age. The Elves called it mithril, and the Dwarves, who valued it most of all, had their own secret name for it. Like ordinary silver, it was easily malleable and could be polished to a brilliant shine, but it was also harder than the hardest steel.
