Alicul

Alicul is a mineral found deep underground on Unus Solem, which is extensively used by the inhabitants of the planet for air travel and electrical applications. Alicul is extremely common within the crust of Unus Solem, forming distinct shiny dark grey quasi-crystals, with a cubic hexoctahedral structure.

Origins and Discovery
Alicul is theorized by geologists to have been created by a massive impactor 1.5 billion years ago, in the same event that created the planetary rings. The first documented discovery of the mineral was in the Sudfell region of Arcea circa 1173RT, with its name deriving from the Sudfellian word "hoverstone".

Properties and Applications
Alicul is a type-2 near-room temperature superconductor, with an upper critical temperature around 30 degrees Celsius, and a lower critical temperature around 2 degrees Celsius. Below the upper temperature, alicul becomes a perfect conductor, beginning to display diamagnetism in external magnetic fields (making it excellent for maglev trains).

When cooled to below its lower temperature, it expels external magnetic fields entirely in the Meissner effect, enabling magnetic levitation. On its own, this would only enable maglev trains, but Unus Solem's strong magnetic field enables sufficient quantities of alicul to lift airships when used in a lift cage. Additionally, its ability to conduct electricity with zero resistance at room temperatures makes it invaluable for lossless electrical distribution grids.