The Green Stones, official name unknown as of yet, are items found in Number Nine's Loric Chest. The string of stones, when thrown, opens up a miniature black hole that sucks in everything nearby. The hole can then be moved to another location and regurgitate whatever it had sucked in.
During a battle in the tunnels of the Mogadorian Mountain Base, shortly after being freed and reunited with his Loric Chest, Number Nine throws the stones at a flock of razor-toothed birds which are sucked in. Nine then transports them and unleashes the birds into the face of an oncoming Piken.