Casting an amulet

I was asked by an acquaintance to attach a fitting to a rather heavy amulet his brother had made, so that it could be worn around the neck. It appeared to have been made in lead or lead-based alloy so after making a small strap and D-ring in silver, I decided to glue the fitting to the back with Araldite rather than risk soldering, even low-temperature.
Amulet Backs Amulet front
I then thought it would be nice to cast it in copper clay and sinter it, to produce a smaller, more wearable version (and perhaps slightly less toxic!). So I made a silicone rubber mould of the original lead amulet, and pressed copper clay into the mould. Copper clay is an analog of silver clay; fine particles of pure metal with a small amount of organic binder and water, to make a kneadable product. After thorough drying it was demoulded then sintered by baking inside a ceramic pot embedded in charcoal, to reduce oxidation of the copper particles. The amount of shrinkage in sintered items is quite large, additionally the result is more porous than cast metal and hence marginally lighter. But I was able to make a fitting in copper, and this time silver solder it to the back.