Thor's hammer (also called Mjöllnir) is the symbol of Thor, a major god associated with thunder in Norse mythology.
Pendants like this were worn by viking warriors to give them strengh and courage.

This is the replica of the Mjolnir found in Steinkier, Norway. Made of sterling (925) silver. The dimensions of the pendant are: 3.1cm (1.22 inch) by 2.2cm (0.86 inch). The original artifact, this item was based on, is dated 9th - 10th century A.D.

A leather cord is included with the pendant.