Moon Emerald

The Moon Emerald is an object that appear in the Sonic X comic series published by Archie Comics. It is an extraterrestrial emerald that once got stolen by the Rogue Rouge.

Description
The Moon Emerald is a large white emerald from space that is partially encased in a meteorite.

Archie Comics
The Moon Emerald was stolen from a museum by the Rogue Rouge under orders from Dr. Eggman, who later used it alongside the Master Emerald to power one of his robots. Following the robot's defeat though, both Emeralds were reclaimed by their rightful owners.