Along with the grey lead Apeiron (the Imperial form of matter, not the shades of same name from Stygia), Thaumium is an arcane metal made by masters of the Matter Arcanum through a combination of perfected gold (orichalcum), silver (lunargent) and mercury (hermium). It is capable of storing Mana, emitting a faint glow in the process, and when properly charged, Thaumium protects its wearer against hostile magic. Because of this, it is highly prized, but can also draw the unwanted attention of rival willworkers that covet such power.