Board Thread:General Discussion/@comment-26248252-20150711214820/@comment-26537563-20150716011111

How could Onion be a gem? He had a video of himself BEING BORN. And before you suggest he might be a half-gem, Vidalia and Yellowtail are still here.

Pretty sure Yellow Diamond is the sillouetted figure that was shown in the extended theme (the one shown at Comic Con) along with the other homeworld gems.