Gem dragons are a line of dragon created through an Estorian breeding project to create dragons to battle aberrations. All gem dragons are adept at using psionic abilities.
During the Illithid War, the Estorians created many weapons to utilize against their foes. After seeing how effective the shardminds were, some of the mages wondered if the principle could be used to create more powerful creatures. This line of thinking ultimately led a group of mages to investigate the possibility of creating psionic dragons to battle the illithids. The project was shrouded in secrecy, and the mages sealed themselves within an extradimensional space to conduct experiments using both shardminds and variety of dragon eggs. For additional security - both from external threats and to mitigate the possibility of unintended consequences - this workspace was sealed from the outside. While the seal allowed for two-way magical communication, it could only be opened by a member of the Estorian royal bloodline. Unfortunately, these experiments did not bear fruit before the end of the Illithid War, and the surviving royal heirs departed.
Eight hundred years later, the sorceress Vyrellis learned of their experiments while gathering an army to battle an invasion from the Far Realm. As the last surviving individual of royal blood, she unlocked the seal, not knowing for sure what she would find within. To her surprise, the experiments had proven successful: six species of gem dragons had been created, each of which had had over eight hundred years to grow and breed. While their numbers were not large compared to their chromatic and metallic cousins, the dragons were eager to help battle against the aberrations.
Their help proved invaluable in turning the tide against the massed forces of the mad wizard Tephra. Once the battle was over, they scattered across the world to claim territories for themselves.
The gem dragons spent their entire lives believing that they were the world's only hope against an unspeakable evil. As a result, they tend to be extremely haughty, self-centered, and arrogant - even for dragons. However, there is also a degree of resentment towards mortals for creating them as little more than living weapons, making them generally aloof and uncaring about the affairs of "lesser races." Few gem dragons are particularly good, but conversely very few are actively evil or malicious. Most are perfectly willing to leave mortals alone so long as they are given the same courtesy.