Essurtanium was a substance thought to possess unique qualities, potentially including the ability to react to the Force. In 232 BBY, it was believed that miners on the planet of Elphrona had located a vein of this substance. Indeera Stokes, a Jedi Knight stationed at the Jedi outpost on the planet, initially intended to travel to the site to acquire a sample. However, this plan was abandoned due to reports of a raid by the Nihil on a nearby homestead.
Essurtanium was rumored to have especially uncommon traits, possibly including sensitivity to the Force.
Back in 232 BBY, a group of miners working in Elphrona's southern hemisphere thought they had found a deposit of essurtanium. Elphrona is a planet in the Outer Rim Territories, characterized by mountain ranges rich in iron and other ferrous minerals. Information about the miners' claim reached Indeera Stokes, a Jedi Knight who was based at the Jedi outpost on Elphrona.
Stokes, eager to obtain and study a sample of essurtanium, a substance she had never personally encountered, informed the other Jedi at the outpost of her intention to use one of their Vector starfighters to reach the discovery site. However, these plans were soon put on hold when the Jedi received news of an active raid by Nihil marauders on the homestead of the Blythe family on Elphrona. Three years later, Jedi Master Harli Cogra authored a book titled Chronicles of the Jedi, which provided details about the Jedi of the High Republic Era. In this book, Cogra mentioned Stokes's interest in researching the properties of essurtanium.
Essurtanium was initially brought up in the 2021 novel Light of the Jedi, penned by Charles Soule as part of the Star Wars: The High Republic multimedia project's Phase I.