Sky-Crystals (or Caelumium) are sky-blue crystals that were brought by craters from space. Larger crystals can be used for Airships or powering Automated Support Drudges and Power Armour. Small crystals allow for certain individuals to focus electricity from their brain and then give the user psionic-like magic. Sky-Crystals are sorted into four classes. Class I crystals, are small and are for personal use. Class II crystals are used for jump-packs, and powered armour. Class III crystals are used for Automated Support Drudges. Class IV crystals are the largest, and are used for powering the Lift Core Drive on Airships.