Arnora's Amulet is a clothing item in The Elder Scrolls IV: Oblivion. It is a blue amulet worn by Arnora Auria. The Hero may discover that the blue amulet is actually a fake and that Arnora also possesses Arnora's True Amulet, which is red.
Jorundr, her husband, requests that the Hero kill Arnora, take her amulet, and bring it to him. They may either choose to kill Arnora to take the amulet or talk to Arnora and obtain Arnora's True Amulet instead.
They may also choose to take both of the amulets to Jorundr, and at that point he will say, "Two amulets, one must be a fake. Clever girl...".