A common criticism of the game is that you can only pick from three classes of Gem — Quartz, Pearl, and Ruby. However, the protagonist is a Defector from Decadence, and these three types were in the lower castes in Gem society shown at the time of the game's release, with Quartzes being standard warriors, Rubies being foot soldiers, and Pearls being servants, so it makes complete sense to make these the castes you could choose from.
