I gave it to her and we were engaged for six months and set a date for the following year. We broke up in Nov of '19 and she gave me the ring back.
Pattylt:
Usually, an engagement ring is hers to do with as she wishes.
Not true. In most jurisdictions, engagement rings are considered conditional gifts. In other words, the engagement ring is considered a gift under the condition that the recipient follows through on the promise to marry the giver. In our case she broke that promise and therefore, forfeited the gift.
You might want to Google different sites. As @Pattylt mentioned, once a gift is given in the US, it is legally the recipient’s gift, UNLESS it was given with, and accepted with, the understanding that in the event of a breakup, the ring will go back to the giver. Increasingly, it seems, as the years advance, women are returning rings after a breakup, but unless the return in event of a breakup has been specified along with initially accepting, there is no legal obligation to do so.
There are times when a young couple becomes engaged and a relative of the groom presents an heirloom ring to be used with the same caveat: return the ring if there’s a breakup.
Since your ex-intended did return the ring, sell it for as much as you can get for it and thank your lucky stars that she did!
Edited to Add:
I googled briefly, knowing that 60 years ago the ring was the lady’s to keep, unless there was an agreement upon receipt to return it in the event of a breakup, or unless the lady just wanted to return it. Of course, a guy could always resort to court, but that’s certainly not necessary here.
THEN, I read the rest of the thread and saw all the uproar! Good grief! Why? The OP already possesses the ring! As Archie would say, “Sell it already and be done with it!” (Rolls eyes!) “Case closed!”