The Blue Orb is a quest item obtainable in Golden Sun: Dark Dawn. It is described as "a shining blue sphere." As a key item, the Blue Orb cannot be sold or dropped.
The Blue Orb is given to Sveta by King Volechek after the activation of the Grave Eclipse, and Matthew's party attempt to flee using Briggs' ship. Volechek throws the orb down to Sveta from his castle, saying he stole the item from Blados, and he hopes the group can use it to defeat him. The item is used in the Yamata ruins, alongside the Red Orb to obtain the Yellow Orb, and is used again on the Endless Wall along side the other two orbs to open a gate so the player may continue. In addition, this orb is also used to help set up the activation of the Apollo Lens, at which point it will permanently disappear from the inventory.