Skystone is a compound containing unobtainium which, when properly processed and implemented, can stabilize skylands and other floating objects. Generally, the anti-gravity properties of unobtainium are uncontrolled and unpredictable, leading to "skyquakes," sudden violent tremors that cause a skyland to spin, turn over, or even fall. Skystone reduces these tremors and balances a skyland's flotation, and is thus instrumental in the colonization of Skytopia.
Skystone was first made on Isla di Pisa, and used to stabilize the otherwise precariously balanced Skyland. Unobtainium is primarily refined into Skystone on Tinkspoit, though it is not the sole producer. The act of processing Unobtainium also stabilizes the otherwise radioactive and gradually decaying element, and reduces the chemical hazards, though it still not perfectly safe to be exposed to for extended periods.
Skystone has a chemical formula of Uo3 C23 H30 N11 O4. This is a planar molecule with the large, Uo atoms sitting below the plane. Each of these three Uo atoms is bonded to another Skystone molecule, so that parallel sheets of molecules similar to graphite are formed.