Truesilver Bar can be created by miners via the smelting skill using one [Truesilver Ore]. This requires a mining skill of 230. It can also be created by Alchemists who can transmute [Mithril Bars] into Truesilver Bars using their [Philosopher's Stone]. The transmute requires an alchemy skill of 225.
Truesilver Bar as an ingredient
Truesilver Bar is used in the following recipes:
Truesilver Bar as a quest item
The Spectral Chalice quest is in the Blackrock Depths and is how miners learn to smelt Dark Iron.