Radium

Radium is an element that can be placed as a tile in the world. In the gallery image, it is shown as a rectangular block for size comparison, like other elements that have a distinct map appearance when built into tiles.

Beyond that, the provided material does not describe any unique properties, harvesting behavior, temperature, décor, or build uses for Radium itself. The available sources instead focus on radbolts and their interactions, including how they behave in motion, what happens when they collide with tiles or other radbolts, and how they are produced and consumed. Radbolt projectiles can be generated from Uranium Ore or Enriched Uranium, collected from ambient radiation, and spent by systems such as Materials Study Terminals, Diamond Presses, Radbolt Engines, and Interplanetary Launchers.

• Radbolt projectiles lose 0.1 radbolt per tile traveled and leave Radioactive Contaminant germs behind in the medium they pass through; in a vacuum they still lose radbolts but do not leave contaminants.
• When radbolts collide with other radbolts, the impact tile releases radiation, Nuclear Fallout, and Radioactive Contaminants per radbolt contained.
• If radbolts hit solid tiles, including Window Tiles but not Pneumatic Doors, they disintegrate and release nothing.
• Radbolt projectiles do not harm Duplicants, which makes them useful for exposing Duplicants with the Radiation Eater trait to radiation without causing direct damage.

Radium itself is therefore only documented here as a placeable element, while the surrounding information mainly concerns the radbolt systems that interact with radiation-based gameplay.