The wedding has never happened and now you want to know whether you can get the diamond ring you gave your fair eyed vixen returned. Your fiancee decided you were not the handsome gentleman that you originally claimed to be or perhaps she dumped you because you are too unstylish to recognize that you are not supposed to wear brown shoes with black slacks. Perhaps she merely doesn't like the cut of your jib and has proffered no other reason why she cancelled the wedding.
Whatever the reason, she is no longer interested in you. So the only question that remains, can you get the expensive diamond ring that you gave her back ?
The answer to this timeless riddle is that it depends. However, a bargained for exchange whereby the consideration was never duly exchanged may allow you recourse in the eyes of the court. Differing jurisdictions may have differing interpretations but many states are starting to follow "No Fault" approach where the reasons for the break up are not considered. That is, if the engagement is broken then the giver is to receive the ring back. The ability to determine the best legal advice on these types of matters however requires that you get legal counsel immediately as each juridiction handles these matters differently.