Rhodonite

Rhodonite is a practice fused gem introduced in the debut episode Giant Woman but then in her second appearance she is re-fused by Christopher Jones and Diamond in a crisis between Peridot and herself as Peridot tries to kill the gems with her flask robonoids from Garnet and the Robonoids where the flasks themselves appeared as Peridot is seen five times controlling their every movements in the battle!

Notes/Trivia
it's been revealed to the gems that Rhodonite's first appearance in Giant Woman was just to impress Steve Universe and for fun as well as to destroy an unsuspecting enemy and in victory!