Legal point: wife/fiancee entitled to keep engagement ring whatever the circumstances, it was a gift, however a family heirloom is returned.
I gave my first engagement ring back to my mother in law on their Golden Wedding anniversary, it had been hers anyway. She was very touched and had never expected it back. The wedding ring along with second wedding ring I sold and got a good price along with other bits of gold.
Second engagement ring I love for the ring itself and wear it daily. It was designed for me along with a lot of other jewellery from the same designer. I did sell the wedding necklace as it is outdated to wear a suite of jewellery nowdays. Anyway I only wore it about ten times in England as not many occasions for that sort of thing, and here in France profonde it was useless! I have kept the matching earrings. I do have quite a lot of inherited jewellery which is beautiful. I am gradually giving some of it to DD and DDiL.
All the remaining stuff will go to my DD and DGDs when I die.
After 20 years my OH and I eventually got married recently . I'm not really bothered about yet more rings as I have plenty. And at 70 seems a bit daft to spend money on expensive gold. So will at some point get around to a silver wedding ring and another ring in silver with a white topaz stone that I have acquired at some point. My DH has bought me silver for my 50th and other bits of silver so seems to make sense.