(Pallasite is a very cool looking kind of meteorite, so I used that for a gem!)

Pallasite was a special experimental gem weapon created by Homeworld eons ago, intended to be deployed in the Gem War. Her gem is a very large strip of iron where her eyes would be, with several crystals embedded within. These serve as her eyes, though she can only use one at a time, and willl glow while in use (enabling an outside observer to see where she is looking).
She was sent to Earth with White Kyanite as her bodyguard, but delays and incidents during deployment left her and White Kyanite stuck out of the conflict and bored. Naturally, the pair grew attached over time, became lovers and even considered abandoning their positions to start a new life together.
Sadly, near the end of the war, they were finally deployed. Though they remained together, they both disappeared following the Gem War. Some witnesses believe both gems to have been shattered in battle, though White Kyanite's sisters are not convinced they are truly gone.

Nude version here.