Igneous Rock

Igneous Rock is a raw mineral in Oxygen Not Included notable for its high thermal mass and low thermal conductivity. It provides no Decor bonus, but its combination of heat capacity and insulating properties makes it one of the best early- to mid-game materials for thermal management. Igneous Rock pairs with Obsidian as the highest Radiation Absorption raw minerals, which can influence placement choices in radiation-prone builds.

Igneous Rock is produced when Magma solidifies. It can also be obtained by recrystallizing melted Regolith, which is a renewable process available on any map and releases substantial heat that can be used for power or heating purposes. On maps that feature volcanoes, Igneous Rock is a renewable ground resource where Magma solidification occurs. It is also obtainable on rocket missions to certain renewable Space Points of Interest: in Forested Ore Fields at a yield of 378–1134 kg per cycle, and in Rocky Asteroid Fields at 216–648 kg per cycle.

Practical uses and interactions:

• Construction: Igneous Rock is commonly used to build Insulated Tile, Insulated Liquid Pipes and Insulated Gas Pipes because its thermal properties slow heat transfer and buffer temperature swings. This makes it especially valuable before Ceramic and specialized Insulation materials become available.
• Processing: A Rock Crusher can pulverize Igneous Rock into Sand at a 1:1 mass ratio (100 kg Igneous Rock = 100 kg Sand). Sand can then be used for glass production or other crafting chains.
• Critters: Stone Hatches will consume Igneous Rock as feed and excrete Coal, providing an early renewable fuel source if you establish a Hatch farm.
• Radiation: Along with Obsidian, Igneous Rock offers the highest Radiation Absorption among Raw Minerals, so it is useful when constructing barriers or enclosures near radiation sources.
• Heat management: Converting Regolith to Igneous Rock by melting and re-solidifying Regolith is a repeatable method to generate Igneous Rock while producing large amounts of heat; this can be harnessed with careful planning to power steam turbines or heat-dependent processes.

Deployment notes:

• Place Igneous Rock as insulated structures around sensitive rooms (electrical, liquid/gas conduits, food storage) to minimize unwanted heat transfer.
• Use in conjunction with thermal sinks or controlled heat exchange systems when you need to temporarily store heat and prevent it from spreading.
• When farming Stone Hatches for Coal, supply abundant Igneous Rock while maintaining comfortable temperatures for the critters to maximize throughput.
• When planning rocket missions, prioritize Forested Ore Fields for larger yields if you need more Igneous Rock per cycle.

Igneous Rock is a versatile, abundant material whose primary value lies in thermal control and early-game resource conversion, forming a cornerstone of many insulating and fuel-production strategies.