My idea is that they add an NPC with daily and weekly quests according to their level. Example: Go in the ud6 and kill such boss or kill 100 mobs of your level, go on the CCDG and pass the floor 50. These are just examples do not need if exactly that, having as a prize:
Daily: 5 stones Blue and red, the level of the quest you picked up (non-negotiable).
Weekly: 5 blue and purple stones from the level of the quest you picked up (non-negotiable).
That's just examples need not be that amount of stones...
Sorry for the bad English