Iridium

Iridium is a refined metal with no corresponding ore form, but it still carries the Metal Ore tag. Like other high-end metals, it can raise a building’s overheat temperature by 500°C, making it a powerful material for machinery that must survive extreme heat. In practice, it serves as a superior alternative to Steel in most situations, since Steel only raises overheat temperature by 200°C and also has a slightly lower melting point.

One of Iridium’s most valuable traits is its ability to push a building’s overheat limit above 600°C when used in certain applications, which is especially important for setups involving phase change refining or crude oil cracking. It is obtainable earlier than Niobium or Thermium, but it cannot currently be mass-produced through industrial means.

Iridium also has the third-highest solid thermal conductivity in the game, behind only Thermium and Aluminum, so it is well suited for heat transfer builds. Its other major strength is radiation handling: it has the highest radiation absorption factor in the game at 0.88, and when used for Tiles it provides up to 70.4% radiation resistance. This makes it especially useful for radiation shielding and for constructing reactor protection walls, where strong radiation resistance and a high melting point both matter.

As a building material, Iridium also provides a +20% Decor bonus, matching the effect of Steel. It can additionally be fed to Plug Slugs and their variants:

• Standard Plug Slugs consume Iridium at a rate of 60 kg/cycle and excrete it at 3 kg/cycle.
• Shiny Plug Slugs and their variants consume Iridium at 30 kg/cycle and excrete it at 1.5 kg/cycle.