The Glass Ghost is a tall humanoid made of bluish-green glass. She has crystals that resemble messy hair. The Glass Ghost wears shoulder pads that are jagged. She lacks facial features, excluding her eyes, which are dull-yellowish and large. Her hands appear to be broken off at the wrists, and they float separately from the rest of the body.
Garnet and Pearl used to tell stories of the Glass Ghost to Amethyst when they first found her to scare her, which worked. While telling scary stories around the campfire, Garnet brings up the story, but Amethyst shows disinterest towards it. Later on, Steven finds trails of broken glass, and while following it, he finds out that the Glass Ghost is real.
The ghost turns the Crystal Gems into glass. She is discovered not to have control over her powers and just wants to be able to touch things. When she hugs Steven's bubble shield, she ends up popping it and poofing herself, freeing her previous victims from the glass incarceration.
Glass Petrification: The Glass Ghost can turn both Humans and Gems into glass.
Anatomical Separation: The Glass Ghost's hands are separated from her body.
Regeneration: Despite the assault by Amethyst, she can regain her form with ease.
Density Control: The Glass Ghost has some control over her density, allowing her to solidify enough to touch things and become hollow enough to pass through them.
In Issue 4, Garnet suggests that the Glass Ghost might be a type of Quartz because she is so strong.
She is the only known Corrupted Gem to have naturally levitating body parts.