Spoiler Alert Spoiler Alert: WARNING! This page happens to contain a lot of heavy spoilers that are all originated from the Overlord author, Kugane Maruyama and his collection of written works. Anime-only watchers and Manga-only readers, please take some time off to reflect it over for a bit before choosing to expose yourself on reading the information below recklessly.

NoImage Alert Judging from the current state of this page, there is no available image on the Overlord Fandom as of yet to help emphasize its appearance. Since it is lacking visuals, this article requires an image for the first time, the kind which should be high quality and distinguishable. You could go out of your way to assist the Overlord Wiki by adding an official image that came from any Overlord adaptation to it.

Celestial Uranium (セレスティアル・ウラニウム) is one of the seven prismatic ores of YGGDRASIL.


Celestial Uranium is a critical element for the Caloric Stone. In the past, Ainz Ooal Gown discovered through a stroke of luck that by gathering vast quantities of this prismatic ore and then expending it, they could earn the Caloric Stone, an expendable-type World Item. Presumably, this metal was found in the Seven Hidden Mines.[1]



The substance has various properties. It will turn into Caloric Stone if enough of the ore is gathered. One is able to fuse the ore with a golem, by creating core from it. The result makes a powerful entity that can be looked at by other players as almost a cheating mechanic.


  • Although Punitto Moe believes that there could be other sources for finding the ore, the mine discovered by Ainz Ooal Gown was, apparently, the first mine with Celestial Uranium discovered on the game.


  1. Overlord Volume 11 Chapter 1: Preparing for the Unknown Land

Community content is available under CC-BY-SA unless otherwise noted.