During the War (Home world gems vs Crystal gems), Home world weren't able to create gems fast enough, so they created "Lab created" gems (Or L.C Gems). They did this by instead of using natural resources from other worlds, using artificial resources created by gems. They quit trying after a couple of attempts, due to the L.C gems not being very powerful. They couldn't summon gem weapons, physically weaker and gems with special abilities couldn't use their powers properly (for example, My L.C gem, aquamarine, can only form wings as big as a usual aquamarine, even though she is taller). The L.C gems that were already made were kept for a while,