Crystal Age summary:

"Us, jewels, and them, sinners, can't die." In this small region of a new earth, immortal beings of stone known as jewels live together in their Cathedral, fighting against sinners, the world and themselves for survival. Amongst all of this, the youngest and most frail of the bunch, Chrysocolla, intends to find the truth about his companions and this world. Heavily inspired on the works of Rebecca Sugar(Steven Universe) and Haruko Ichikawa(Land of The Lustrous)