Well, here is the photo of the finished pendant.
After I had put it together, I thought that it needed something to make the heart “pop” (stand out from the main design). I used a technique called Keum-boo (also spelt as Kum-Boo or Kum-Bu which is Korean for “attached Gold”) to apply a thin layer of real gold to the silver.
This gilding technique is used a lot with PMC pure silver (although I mostly use 24ct gold paste especially made for PMC), as they are both pure metals and bond well together. The heart charm was made from PMC so I didn’t have to prepare it apart from heating it to burn off any contaminants from the surface. If it was sterling silver, I would first have to depletion gild it to get a thin layer of fine silver on the surface..
The gold was applied to the heart and then I heated the charm till it glowed a dull orange (this gets both metals at the right temperature for their atoms to bond together) and then applied pressure (burnished) with an agate burnisher to create the permanent diffusion bond.
I made a new jump-ring and re-attached the heart to the main piece. Another polish and it was finished and ready to photograph. A bit more work than I first was expecting but I think it made a real difference to the design.