The emeralds are do hard to get, so they should come out automatically after you upgrade it to level 1.
Level 1: Holds up to 2
Level 2: Holds up to 4
Level 3: Holds up to 8
(Custom level) Level 4: Holds up to 10
Level 1: Holds up to 2
Level 2: Holds up to 4
Level 3: Holds up to 8
(Custom level) Level 4: Holds up to 10
