Tourmaline wasn't always happy on Homeworld. After the first war began on Earth, many Rebels were captured and used to help create a geoweapon a.k.a, the Cluster. There was one gem, however, that was spared: Tourmaline.

Rose Quartz did not know of any sign of another Rebel nor did Tourmaline know that her leader was still alive. Blue Diamond insisted on letting her join the Blue Diamond Society, hence Tourmaline was treated like a Pearl except better. Blue Diamond believes that Tourmaline is a "special" gem knowing that she's a deformed gem.