Mercury Clan

The Mercury Clan is one of the three canonically mentioned clans of adepts in the Golden Sun games; the others being the Mars Clan and the Jupiter Clan. It was based in modern-day Imil in the ancient past.

History
When Alchemy was sealed away the Mercury Clan was designated as the sworn guardians of the Mercury Lighthouse near Imil, given the responsibility to ensure that the Lighthouse is never activated so that Alchemy's seal may be broken. In the present age, only four individuals are known to be alive: Alex, Mia, Rief, Nowell, Justin and Megan. Alex breaks his bloodline's code in Golden Sun by helping Saturos light Mercury Lighthouse with the Mercury Star and travelling with him across Weyard to activate all the rest. Mia, in response to this betrayal, joins Isaac's party in pursuing Saturos and Alex.

Connection with Mars Lighthouse Symbols
Because of the mutations and special abilities other clans are known to have, such as the dragon-like characteristics of Proxians and the alleged ability of Jupiter Clans-people to fly, it can be speculated rather easily that Mercury Clan member hair color can be attributed to their alignment with the Mercury element. Mars Lighthouse reveals that each element has a corresponding symbol associated with it. The symbol of the Mercury Clan is the fish. However, neither Mia nor Alex appear to have any actual resemblance or characteristic of this symbol.