The Master Precioustone, also known as the Precioustone, is an object that appear in the Sonic the Hedgehog comic series and its spin-off comic series published by Archie Comics. It is a magical green crystal from Maginaryworld, weaved out of the dreams and hopes of people of various dimensional worlds, and is used by goddess Illumina to manage all dreams.
The Master Precioustone possesses magical properties and serves as the gateway to Maginaryworld and is as well the nexus to its reality. Additionally, its power supports the existence of extra-dimensional worlds.
For an unspecified amount of time, the Master Precioustone was used by Illumina to manage all the dreams originating from Maginaryworld. When Illumina, in a moment of self doubt, split into two beings, her dark half Void sought out the Master Precioustone and drained its power. This caused the Master Precioustone to shatter, creating the many Precioustones.
To restore the Master Precioustone, Lumina, Illumina's other half, called upon Sonic, Tails, Amy and Knuckles to help gather up the Precioustones throughout Maginaryworld and rebuild the crystal. Eventually, the Master Precioustone was restored, and Lumina and Void merged back into Illumina.