|Users||Ainz Ooal Gown|
|Debut||Overlord Volume 6 (Mentioned)|
This World Item is unique and is one of the hidden items of YGGDRASIL. It can be obtained by gathering and stockpiling vast quantities of certain types of prismatic ores and then by expending a certain amount of them. The guild Ainz Ooal Gown managed to produce a Caloric Stone by accident after they had stored an unspecified amount of the prismatic ore Celestial Uranium.
The Caloric Stone has multiple uses, from being used as a golem's core to enhancing weapons or even armor.
- This World Item is unique in that it does not exist as a single standard item, but as a vast quantity of valuable ore.
- Ainz Ooal Gown used the Caloric Stone when they learned that they could obtain that expendable-type World Item in the same way as before.