This is part of the DragonSoul continuity.
The four members were synthetically created by channeling the power of a star into a living being. This meant that 4 Quadrants were sacrificed in their creation.
They had snake-like bodies and white gems, instead of the classic blue.
Each member had a name to distinguish them from your average Gem and to commemorate the star that was sacrificed to make them:
Diamond Shí èr