This generic Thor's Hammer pendant is made of bone and can be supplied with a length of leather thonging for no extra charge.
 
Pendants of any kind aren't as common in a Viking Age context as most people seem to think, and where they are found in a burial context they seem to be worn by largely by females.
 
They make an excellent additition to modern day wear, but we advise restraint in the wearing of pendants as part of a historical impression.  Feel free to buy as many as you want, but if you are going to include one in your Viking Age Costume, please wear one at time!