Moonstone

Moonstones are special gems typically made on moons of other planets. The color of that moon will determine the color of the moonstone. Moonstones are typically higher on the social ranking being around a sapphire or aquamarine ranking. They're typically not made for fighting, but have a high pitched screeching able to poof gems as a self-defense mechanism (absent from era 2 moonstones). Moonstones are very rare since a planet's moon hardly ever has enough resources to make a proper moonstone, so most end up being defective. Most are made for entertainment purposes, such as singing, dancing, or even plays in certain cases.

This Moonstone was lucky enough to be an era 1 moonstone that wasn't defective. Moonstone helped in the war by performing songs on Homeworld to try and calm down the gems of the Crystal Gems rebellion. She is one of the rare gems still surviving from era 1, and originally being part of Pink Diamond's court, she was reassigned to White Diamond's court with the shattering of Pink Diamond. She is one of White Diamond's personal entertainers and holds her position in high regard.

Moonstone is bubbly, upbeat, and even in certain cases seductive. However, since White Diamond found her quite the amusing distraction, she forces her to always sing, even when she's just trying to tell her Diamond something. Because of this, it happens more often than not that gems will find her annoying because of her constant singing.

Moonstone sang her way through homeworld. Some gems thoroughly enjoyed her singing, others did not care for it. She met a Sapphire, the two enjoyed each other and complained about their treatment. They agreed to fight for one another and even used fusion out of the sight of other gems. Moonstone was sitting with her Diamond one day, singing a song in tune with the tapping of her weapon, a small show cane. When, all of a sudden, Ocean Sapphire burst through the door. "Your clarity!" She began, Moonstone looked in awe at the brave sapphire. The sapphire claimed that the Moonstone deserves more than just being a singing toy to her Diamond, she is a rarity, rarer than any sapphire. White Diamond laughed at the Sapphire and pitied her claims. Explaining that Moonstone is nothing more than her toy. Moonstone looked at her Sapphire, then to her Diamond, what will she do? Was she going to stand by and watch the death of her lover? 

Moonstone acted, she took the hand of the Sapphire before she was shattered and fused with her. There, after the smoke cleared, stood Gem Silica. A strong fusion with the power to see into the future, and a wonderful singing voice that could destabilize gems, and sometimes, when she sang just right, turn them into mindless slaves to her, only for a short while. 

The gems ran away to a faraway planet called earth, it was post-war and they were safe.