Lyrium

Lyrium is a valuable but dangerous mineral that forms beneath the surface of Selune and sometimes lands on Kios.
The mineral is extremely volatile and sometimes explodes for no apparent reason. Physical contact with raw lyrium ore will cause serious injury and psychological damage. It is now used throughout Fulmenos for things such as weapons, tools, automatons, and Spelljammers. These ships are able to travel through space and even the Frozen Sea.