The Argon ring is a special accessory in Dragon Quest VIII.
The Argon ring is an accessory that only the Prince or King of Argonia may possess. The gem on the ring is made from the heart that an Argonia Prince obtains from defeating an Argon lizard.
An Argon ring was once possessed by Former Argonian Prince, Eltrio. He later presented it as a gift towards his love, Xia, a Dragovian woman. She later kept the ring as a reminder of him after he died attempting to reach the Dragovian Sanctuary to meet with her again.
Years later, their son, The Hero defeated the Lord of the Dragovian in battle and was met with gratitude. The Hero was instructed by the Dragovian Lord to speak with Chen Mui in regards to learning about his own past. Upon doing so, he was presented with the Argon ring that was kept by his mother.
The Argon ring can only be equipped by The Hero. When worn, it provides an attack boost of +20 and an agility boost of +20.
The ring is also needed to trigger a second ending for the game.