Ceratimus is a ceramic-based material equivalent in strength to hard metal. It is manufactured by the Pyrmidian Ghouls, githyanki and the Xi Institute. The formula for making ceratimus is a closely guarded secret. The inventors of it were the Dezellâm.
In the Creation War, the Dezellâm were sent to the Sands of Hell by the primordial Storralk. They were tasked with harvesting crystals growing from the bodies of xorn. Being a pacifist people, the Dezellâm followed catch and release procedures when they harvested the xorn's precious cargo. The Xorn of Stafknir Hrerbjof roam the shallow Underdark beneath the desert. Since they are not native to Bal-Kriav, they produce a white crystal on their bodies that grows like a cyst on flesh. Storralk learned from Geb that the crystals are a variation of deep crystals and useful for holding psychic energy. Storralk wanted these crystals to help his troops against psionic heavy primordials that turned against him and to combat those angelic foes with great psionic potential. In the Demon Spawn War, the Dezellâm used powdered deep crystals to fortify their ceramic shields. This powdered deep crystal is used when making ceramic, resulting in the material ceratimus. The Pyrmidian Ghouls are thought to have learned the process of making ceratimus from Dezellâm tomes found in the ruins of Gallo-Bagd.
Ceratimus is unaffected by electricity. When used to make half-plate or better armor, it provides energy resistance - electricity 5 to the wearer. It also weighs half that of normal armor. Ceratimus can only be used to make armor types suitable for ceramic molds; shields, breastplates, half-plate, full plate. Armor made of this material is treated as one category lower, so full plate is normally heavy armor, but a ceratimus suit is treated as medium armor. This reduced category only applies to arcane spell failure, armor check penalty and movement. It does not apply to maximum dexterity bonus because it is still a bulky armor. The same adjustments apply to a breastplate, which would fall into the light armors.