The Sol Mask is an important item available in Golden Sun: Dark Dawn. It is described as A mask in the shape of the sun. The Sol Mask is obtainable in the Ouroboros once Amiti has joined the party. Its primary and only function is to be fixed into the Alchemy Forge in order to get it functioning fully. Although it leaves your inventory permanently at this point, the mask can always been seen fixed to the forge.
The Sol Mask has a counterpart, the Luna Mask, which is used to power the Alchemy Well. However, as the Luna Mask is already affixed to the well before the player arrives, it cannot be obtained.
As an important item, the Sol Mask cannot be sold or dropped.