Mercury

Mercury is an element with unusually strong thermal properties. It has a very low specific heat capacity and a high thermal conductivity, making it effective at moving heat quickly while changing temperature slowly. Its liquid temperature range is also very wide, from -38.8°C to 356.8°C, which lets it remain usable across a much broader range of temperatures than most liquids.

In practical base design, Mercury is best known as a high-performance thermal medium and a material for liquid locks, especially in high-temperature environments before Crude Oil is available. Its wide liquid range makes it a strong choice wherever a stable, conductive liquid is needed over extreme temperatures. It also has a default mass of 600 kg, which is useful to keep in mind when planning storage or plumbing layouts.

• Mercury can be used to build liquid seals that remain reliable in hotter conditions than many other liquids.
• Its low specific heat means it responds quickly to heat input and output, while its high conductivity helps spread temperature efficiently.
• Because it stays liquid over such a wide temperature band, it is particularly valuable for machinery or piping that must function through large thermal swings.
• When cooled below its freezing point, Mercury solidifies into a form that can be used for buildings intended to operate in deep-freeze environments below -40°C.

Mercury also had an unusual history during development. Before version 207167, a bug could cause the top of the world to turn into a giant Mercury pool, continuously spawning liquid across the map and causing severe performance loss. This was the only time Mercury appeared outside Creative Mode before the game’s full release.