Uranium (5e Equipment)
From D&D Wiki
Price per dose: 5 sp/lb.
Uranium is a metal that can be found in veins in underground rocks. It is green and emits barely visible light in the dark. It is very dense in its pure form, with a single cubic foot weighing 1100 pounds. Uranium's danger comes from exposure to it, even from a distance for a short amount of time. Bigger pieces of uranium emit larger ranges of radiation. Five pounds of uranium has an effective range of 5 feet. This range increases by 1 foot for every pound of uranium.
Any creature within range of the radiation begins to feel the effects of uranium after one uninterrupted minute of being within range. Creatures gain one level of exhaustion at the end of each minute they are within the range of the uranium's radiation. Exhaustion gained this way takes the form of tumors, rather than fatigue, and cannot be removed by nonmagical means without surgery.
In a typical fantasy world, uranium has no practical use, and is worth almost nothing. This can change depending on the technological advancements and mineral knowledge of the setting.