So this is my gem. She is an ember, and is trying to join the Crystal Gems because she has a past on Earth...
Here's her backstory:
Pink Diamond watched as her first pearl was being created. Then, something happened. The light turned fiery orange, and the pearl started taking a different shape. Suddenly, there was a flash, and the Kindergarten went dark except for a warm glow from the pearl's body. Pink stared as a unique and unknown gem, an ember, walked out of where the pearl was before. She was still glowing faintly. She was the first ember to ever exist. Pink quickly glanced around the room, making sure that Yellow or Blue weren't watching. Seeing that no one else was there, she grabbed Ember with her hands and went to the other side of the planet, hiding her safely in a cave behind a waterfall. As long as the waterfall was there, she wouldn't be able to leave the cave. The waterfall was enchanted against gems. After 2,400 years, the water finally dried up, and Ember emerged.