They are a sort of gear in Idle Heroes.
Dislike different riggings, Treasures (Stones) are bolted to the saints and can’t be unequipped.
Fortunes (Stones) are opened (for nothing) when the Heroes achieved level 40.
Redesigning Stones costs Gold and enchantment dust Magic Dust.
Treasuries have 6 levels altogether. You can investigate the tables underneath for more subtleties!