The Caloric Stone is unique and is one of the hidden World 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.
Furthermore, the guild of Ainz Ooal Gown already knew a secret method on how to farm Caloric Stones with the prismatic ores. However, it was revealed that method of doing so will just served to deplete away a lot of such metals from the Seven Hidden Mines. Only in the Web Novel, when Bellriver had the role of strategist, he was hoping to disclose their method to their enemy guilds and have them take turns using the mine's ores to somehow produce a Caloric Stone while fighting over it. The scheme Ainz Ooal Gown had planned in mind regarding the method of making various Caloric Stones involves setting up both the 2ch Alliance and Trinity with the same information provided to them.
The Caloric Stone is considered to be a material with various applications. For starters, it could be used to create a golem's core. In addition to that, the World Item is said to enhance the likes of weapons or armors too. Similar to Ouroboros and Five Elements Overcoming, it is also one of the items that allow the holder of this World Item to make requests to the game developers.
- 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.
- Ainz believed that the reason why they had managed to attain the Caloric Stone was entirely due to an extraordinary stroke of luck.
- Although the Caloric Stone is a consumable World Item that can only be used once, it is not classified as part of the "Twenty."