Demantoid has a build similar to that of Garnet's, except she lacks arms and a head. Instead, there are green spherical devices at her shoulders that connect wirelessly to green, robotic arms, similar to Peridot's limb enhancers' fingers. Her gemstone hovers above her body, where her head would otherwise be. Two green hands, either gloved or her actual "skin", come out of the rounder ends of her arms.
She wears a green Homeworld soldier uniform, a Yellow Diamond symbol on her torso, and high-waisted black footie pants that have green on the bottom of her feet.
Nothing is known about Demantoid's personality yet.
Demantoid possesses standard Gem abilities, bubbling, shapeshifting, fusion, regeneration, agelessness, and superhuman strength/durability.