All items, equippable or not, that are counted as Artifacts are special, stronger items that do not appear in the Buy menu at vendors, contrary to Common items. These are bought and sold individually and usually are unique, and if one appears in the Artifacts menu of a town's vendor that one item can be bought by itself and then be sold by itself anytime afterwards to reappear in the Artifacts menu. The vendor shopkeeper will specifically remark about how rare a find your Artifact is whenever you specifically sell one.

“Orihalcon is the most powerful forgeable material in Golden Sun: The Lost Age and Golden Sun...

Orihalcon

Sol Blade

Assassin Blade

“Cursed items are weapons and armor that carry an unremovable curse. Once such an item is...

Cursed items

“A Spirit Armor is an Armor-class piece of armor found in Golden Sun. It is acquired randomly as...

Spirit Armor

“The Cleric's Ring (Datenshi no Yubiwa/ Ring of the Fallen Angel in Japan) is a Ring available in...

Cleric's Ring

Burning Axe

“A Healing Ring is a Ring-class piece of equipment found in Golden Sun and Golden Sun: The Lost...

Healing Ring