Peridot

Peridot is an experimental gem. She is one of the first prototypes for testing how a non-fighting gem could be designed to fight. Her cybernetic enhancements have various built in weapons, and she has learned to summon her own weapon (A laser sword). Without her cybernetic enhancements, however, she is a normal peridot. She does have the mindset of a soldier, and is ready to fight at any moment. After many experiments with the enhancements, it was deemed that the experiment was a failure and they continued testing them for other uses. After this, her diamond considered her not needed, making her a useless gem. Having the mindset of a quartz but the body of a peridot, she was a confused gem with no place in homeworld. Her diamond thus decided she should be shattered, as she could potentionally cause problems in the future.

After the threat of being shattered by her diamond, Peridot knew that she had to flee, or it meant death. She fled to the only place she knew was safe. Earth. She had heard the rumors about the existance of the crystal gems, and was prepared for any sort of battle she could run into....
With the assistance of her enhancements, she was very quickly able to create a home for herself out of scraps from abandoned ships and ruins.