Blue Diamond's Gem Object is a Gem-made artifact that was given to the Crystal Gems at the beginning of Season 6.
Description[]
The object itself is the size of a dinner plate, and oval in shape. Numerous colors can be seen swirling inside it, and its surface is as smooth as glass.
Little is known about the object itself, but it is seen able to reverse the effects of White Diamond's brain-washing, able to regain memories towards those exposed to it in a flash of light.