Dumortierite Quartz is a grey-blue fusion gem that dons two pairs of arms and a semi-fused gem, Dumortierite Quartz. She has light grey-blue skin and dark grey-blue spiked hair, her eyes have pupils and are the colour of Aventurine's eyes. Her outfit is a fusion between Amethyst's and Aventurine's and in dark blue colours.
Dumortierite Quartz has a personality of both Gems, indicating that she is an unstable fusion. Her personality switches between Amethyst's and Aventurine throughout the episode , this includes their voices, and is very destructive.
All gems and fusion gems have the ability to summon a weapon, shapeshift, fuse with other gems and retreat to their gemstone after becoming injured to heal, this is shown in Garnet. Activating her gems summons a spiked polearm.
- Since Amethyst and Aventurine share the same spot for their gem and as their fusion is slightly unstable, their gems semi-fused together.
- Both Amethyst and Aventurine are part of the Quartz family, therefore their fusion is also part of the Quartz family.