The Caesium Bar is a material required in Caesium Armor and the Elemental Rod. Its prerequisite material is Caesium Ore, which is found in the Underworld in large pockets much like Hellstone. This ore can be found floating above lava, or submerged. It can only be mined with a Hamdrax or better pick. The name is pronounced "SAY-zee-uhm."
This material is unrelated to the caesium that exists in the real world, thus the pronunciation is correct.Its in-game appearance is pictured at right.
To make a Caesium Bar, 6 (six) Caesium ore is required.