This is the first in-detail analysis I write on the animated series, Steven Universe. As such, it will include spoilers; for a spoiler-free review, see my earlier article in this blog.
The Crystal Gems are the main characters of the series: Garnet, Amethyst and Pearl (and Steven!) They’re aliens (in Steven’s case, half-alien) who live on Earth because, 6000 years ago, their people tried to exploit our mineral resources and a faction opposed it. They saved our world but ended up stuck on it. A few years ago, one of them, Rose Quartz, fell in love with a human, and conceived a child, Steven- at the cost of “losing her physical form”.
The show’s creator, Rebecca Sugar, has stated that she based it on her relationship with her own younger brother. If so, we can assume that Steven represents her brother- but which Crystal Gem is Rebecca? Apparently, it’s all three! This is insinuated in the episode “Fusion Cuisine” when Steven must pick one of them to pretend to be his mother but cannot bring himself to choose, so they fuse into a single being instead. Additionally, there are whole episodes dedicated to exploring his relationship with each Gem separately.
The show seems to be going for Freudian Psychology: Pearl is the Superego, logical in all her decisions; Amethyst is the Id, nothing but primitive impulses like hunger and mischievousness; while Garnet is the Ego, the part that makes the choices (or as Amethyst puts it, “She’s the Boss!” Though Pearl doesn’t seem too happy about it.) So, each Gem represents Sugar in a different way.
There are a few facts that affect this theory, though. The first is the truth about Garnet. It is eventually revealed that she is *already* a fusion of two Gems- Ruby and Sapphire. So whether she counts as a character or two (or three!) and what they represent is still up in the air at this point (though note that Ruby appears to be impulsive while Sapphire appears wise- so they have their own Id (Ruby)/Superego (Sapphire)/Ego (Garnet) thing going on.)
There’s also Steven’s mother, Rose. Though she is “gone” she has influenced his life directly and indirectly- from the stories the others told him about her, to items and messages she left him, to the powers he inherited from her. It even seems that the gemstone in his belly button was once hers, which suggests some part of her might survive inside (we have seen other Gems regenerate their whole bodies as long as their gemstone remains intact.) It’s possible in some future episode, Steven will be able to directly contact his mother. This show is all about unusual (but loving) relationships.