Notes:

Yes we could argue that the episode was non-canonical, however the Uncle Grandpa episode was also supposed to be non-canonical, yet everything in that episode turned out to be canonical (UG discloses that Steven's gem isn't a quartz, and teaches him to use his gem weapon).

I used to joke about how Onion was a sneople, and that the Sneople created the Gems – now I'm starting to think it's all true…