Legal Question in Family Law in California

Unlikely since it was a gift.

Actually, California has a statute on this very topic that seems to say you get the ring back if you are not the one who breaks it off. The only cases in which the statute has been applied, however, are situations in which family properties have been transfered to the bride and groom by parents, and other major asset gifts in contemplation of marriage. There are no published cases I could find on what happens to the ring, since it is a more personal gift. But the statute by itself would seem to say you get it back if you aren't the one who breaks it off or if you break it off for just cause.