Cross-Gems are special Gems that play a semi-central role in Soul Fandom. These are mysterious Gems that are not born like normal Gems or Gems from a kindergarten. They are considered "fusions of two Gems' essence" due to their unique way of creation.
Like normal Gems, Cross-Gems are characterized by their gemstones, embedded somewhere on their bodies. The canon Cross-Gems have a unique placement of their gemstones with unique shapes. Canon Cross-Gems take on a feminine figure, usually that of a child.
Cross-Gems are shown to have the same strength as Fusion Gems, displayed by their unique abilities and powers. They possess the rarest of Gem abilities such as copying other Gems and bending space itself. They also seem to be resistant to mind control such as Blue Diamond's.
Unlike normal Gems or Kindergarten Gems, Cross-Gems are created during a specific time called "Glimmer Season", which started 2,000 years prior to the series. These Gems are more considered "born" more than "created" due to the different process.
During Glimmer Season, a Gem's gemstone glows faintly. At this time, two Gems may choose to "mate". Glimmer Season is estimated to last for three weeks. Approximately five weeks after "mating", the Gem with the feminine form "gives birth" to a Cross-Gem, the new Gem coming from her abdomen. The two Gem "mates" are considered the "parent Gems".
- Cross-Gems are mixes of colors of their parents.