The Phoenix Crystal is a powerful and fiery crystal linked to the phoenix that bears it. Though a lot of people would pay handsomely for one, it’s probably not a good idea to steal a Phoenix Crystal unless you happen to enjoy being hunted by a large angry bird that breathes fire.
The Phoenix Crystal is shaped like an egg and glows like a coal with an orange colour. It also has a little ornamental claw attached to the bottom.
This crystal plays a big role in the episode "The Code", where Aerrow and Piper are intent on taking one, but as they grab one, the Dark Ace steals it, while giving off a little pun to them: "Aerrow, so nice to steal from you again." After a little fighting over it, the phoenix emerges into the cave, trying to regain the crystal. They all escape the phoenix and Piper and Aerrow get away with the crystal, only to get it confiscated by the Rex Guardians. The Hawks agree to their challenge of the code, only to get defeated. Harrier, the leader of the Guardians, gives their prize of the Phoenix Crystal to the Dark Ace as a peace offering for the safety of their Terra. The Dark Ace totally crushes Harrier's pride by telling him honour is overrated, only to punch him out afterward. An army of Cyclonians have been waiting to take over Terra Rex after they received the crystal. The Storm Hawks fend off the Dark Ace and then make friends with the Guardians.