Ok so I've been thinking some more about gold burst. I'm going to keep calling it that since I don't have any other name for it. That would be the primal equivalent to Gold Rage.
My suggestion about the ability is that instead of this being another wackum damage type ability why not make it a heal? Dragons are actually lacking in that one area having only a single targetable heal that's on a rather long timer. If we wanted to make it a little more interesting why not make it a targetable Refreshing Breeze ability.
Now before everyone jumps on me I'd like you to keep in mind that dragons have 3 multistrike type abilities (Ravage, Silver Strike, Gold Rage) so it would not be unresonable to have a 3rd heal.
As a Helian spellcaster type dragon I just don't see the need for another big numbers type of attack. I think it also makes sense if you link the timers between GR and GB. You have to decide wether you are going to damage something or heal. I also think it would be more valuable to a dragon tooth and clawer type than a new primal attack would be.