After the events of "Change Your Mind", Goldstone was given a choice to begin a new project- to work to undo the Cluster prototypes and restore shattered gems. Overwhelmed by this task, he rejected it and took an explorative vacation to Earth with Tanzanite.

He secretly wants to join the Crystal Gems, but harbors too much guilt and attachment to his Homeworld status to do so. He's trying to internally work through it all.

Perhaps with enough time and convincing, he'll come around.