I mean, you really can't get more unique than this: wax seal necklace on vintage/antique watch chains with letter engraving. We also used a rectangle bar link from an antique watch chain that is engraved with flowers on two sides. 

Bonus: you can add your own charms, or even remove the wax seal pendant to create a custom charm necklace. 

Details:

• Victorian-style wax seal, gold-filled or 9K
• Vintage/antique gold-filled watch chains and clasp, 16" chain
  
• Antique gold-filled watch fob pendant with 'DHF' engraved, 1" long (engraving possibly added later, since the letters are not backwards the way a traditional seal would be)