I Am Number Four Wiki

One thing I remember is about your Chests. The Inheritances. He told me they would each contain something - he called them Phoenix Stones, I think - taken from the heart of Lorien. Although he called them stones, I don't think we need to take that literally, the phoenix stones could come in any shape or form and when restored to your planet these items should jump-start the ecosystem. I believe right now you're in possession of the tools to bring your home world back to life.

–Malcolm Goode, The Fall of Five