Yes, all three of you are right. It is indeed the engagement ring. Extra "points" go to Evelyn for catching the solitaire/solitary pun.
Incidentally, if you enjoy this type of warped humour, which describes innocent acts in heinous terms, you might enjoy the old folk song
John Barleycorn . It describes the planting, growing, harvesting, and brewing of barley in a way that makes the workers sound like hardened criminals whose rap sheets would include collusion, assault and battery, conspiracy to murder, and murder. As is true with most folk songs, there are many versions of it. Some go into more gruesome detail than others.
Joy,
Lynn