Cairngorm (カンゴーム, lit Kangōmu) is a Gem who appears midway in the story. They used to be the inner shell of Ghost Quartz, who has a multilayered structure and thus two personalities. After Ghost Quartz was taken to the moon, they became active in their stead.

Ghost Quartz is one of the Gems, they work as a librarian and take part in patrol duty. They are also in charge of the long-term recovery facilities located on the fourth floor.

Author note: I'd like an VA who an do both Cairngorm's serious and mature voice, and Ghost quart''s light, fluffy voice. If your not able to do both, but want to audition for just one, then i've left some lines for you! :) So if you want to just do ghost, then you can.