Gem Dragon

Gem dragons were a type of dragon with crystalline scales. They were aloof, solitary, and self-centered. They spent most of their time on the Inner Planes.
Amethyst dragons were neutral, logical dragons. They had lavender skin and crystal-like scales. Their breath weapon was a blast of concussive force, and they were known to burrow into the ground. They were also the most powerful of the gem dragons.
Emerald dragons were reclusive dragons with a lawful bent. They are inquisitive about history, but also paranoid and distrustful of visitors, whom they deter by setting traps in and by their lairs, and with their breath weapon, a powerful blast of wind. They had scales in many shades of green, with a scintillating appearance that makes the dragon seem to be in constant motion.
Sapphire dragons were territorial, militaristic dragons who normally lived in the Underdark. The majority of their diet was composed of giant spiders, and sapphire dragons considered all the evil races of the Underdark their enemies. Their breath weapon was a blast of noise that caused panic. Because of their sparkling, multi-blue-colored scales, they were sometimes mistaken for blue dragons.
Topaz dragons were erratic, antisocial gem dragons who were often selfish and disinterested in things that did not affect them. They preferred to live by beaches, and enjoyed the feeling the sea wind against their faceted, yellow-orange scales.
Crystal dragons were friendly, curious gem dragons. They enjoyed conversing with other creatures but sometimes came into conflict with white dragons due to shared preferences in habitats. They were chaotic neutral and had a blinding cone of white light for a breath weapon. They were the smallest of the gem dragons and had translucent, crystalline scales.
Obsidian dragons were the most intelligent of the gem dragons, but also the most dangerous. They had smooth, black, glass-like scales that had razor edges and could breathe a cone of fire. They preferred to lair near volcanoes, and were notable for their psionic abilities.[3]
Beljuril dragons were rare and reclusive gem dragons that lived only in seismically active environments.