Nummite

A shy and timid gem. He's quiet and resourceful. He isn't afraid to  speak up, though, and can be pretty intimidating when he's mad. He's  very cunning and can use his tiny size to his advantage.

•Has gravity manipulation powers.

Nummite An ex-Homeworld gem, who  was created to be a weapon fixer/eye for hire. If a gem thought that  another gem was doing them wrong, Nummite can be hired to spy for them. 

He  was created during the war, to build and manage weapons among the  Bismuth. He didn't work with metals though, because he was small and  lithe, and not very strong.