Tales of Tolgard
Mithral (also known as mithril) is a very rare, silvery, glistening metal that is lighter than iron but just as hard. When worked like steel, it becomes a wonderful material from which to create armor and is occasionally used for other items as well. Mithral armors are lighter then their iron counterparts.
An item made from mithral weights half as much as the same item made from other metals. In the case of weapons, this lighter weight does not change a weapons size or ease of which the item can be wielded. Items not primarily made of metal are not meaningfully affected by being partially made of mithral. Mithral easily accepts magical enchantments which makes it a sought after material for magic items,
Mithral was for a long time difficult to acquire and wearing some showed a person had resources and money at their disposal. In modern days though, mithral is common place enough that few people even raise and eyebrow when they see it. The benefit of the weight reduction by the user is still felt just the same.
Any references to ancient dwarves using mithral coins are considered by modern historians to be apocryphal and rooted more in legend than fact.