The Puffed Heart casing has been carved from wax to fit the heat treated 10mm sapphire heart stone.  Then cast in silver, the pendant is made and the stone set, polished and sent tobe gold plated in 22ct yellow gold.  It is sold on an 18" paperclip chain which is also silver with 22ct gold plate.  
The yellow and blue sapphire will be in stock soon. I have an Aquamarine and a ruby to make up.