Isn't much of a cheat, but the game does leave you clueless on how to obtain it.(the good ol' days of Final Fantasy 1) After you complete your task in the ice cavern, I bet you are left wondering, "Now what can I do with this leviastone? Is it ediable?" Sorry but the answer to that question is no... but to answer the question as to its use, take your ship to the southern continet to the small desert south of the Gulg Volcano. Stand in the center of the desert and use the stone as an item. In a short but cool cut scene, you will obtain your airship.