Iron Ore

Iron Ore is a common metal ore and one of the most abundant raw metal resources in Oxygen Not Included. It appears in large quantities in the Caustic Biome and in smaller deposits in oil biomes, making it a dependable early and midgame source of metal for colonies that have not yet built up more specialized industrial pipelines.

Unlike some other metal ores, Iron Ore does not provide a decor bonus or a special thermal overheat advantage. Its main value is practical abundance: it can be refined into Iron, which is then used as a precursor for Steel. Because Iron Ore is found so much more widely than many competing metal ores, it is often the most convenient choice even when other materials would be better for a specific task.

Iron Ore can be processed in several ways:

• Metal Refinery converts 100 kg Iron Ore into 100 kg Iron. This requires Duplicant operation.
• Rock Crusher converts 100 kg Iron Ore into 50 kg Iron and 50 kg Sand. This is less efficient and generally not recommended.
• Rust Deoxidizer produces Iron Ore as part of its output: 750 g/s Rust + 250 g/s Salt = 570 g/s Oxygen + 30 g/s Chlorine + 400 g/s Iron Ore.
• It can be harvested from rocket missions in Space Debris at a rate of 90–270 kg per cycle.

Several critters can also consume Iron Ore. Stone Hatches eat it and excrete Coal, while also increasing the chance of laying Smooth Hatch eggs. Smooth Hatches eat Iron Ore and excrete Iron at 75% mass, making them a simpler alternative to full refining setups, though with lower efficiency than a Metal Refinery. This can be useful when you want iron production with less machinery, cooling, and duplicant labor, and when the byproduct meat from ranching matters. However, a single Smooth Hatch processes only 100 kg per day, so large-scale iron production still favors industrial refining.

Shove Voles can eat Iron Ore debris and excrete half of that mass as Iron Ore tiles, which then lose additional mass when mined. Since they can be fed more plentiful materials with no real drawback, using Iron Ore as their food source is inefficient and not recommended.

In practice, Iron Ore is valued less for unique bonuses and more for how reliably it supports a colony’s metal economy. It is abundant, it refines cleanly into Iron, and it can serve as a flexible feedstock for ranching or secondary processing when more advanced metal sources are unavailable or too scarce to spend freely.