The one thing to remember with class rings is listen to the clarity of the tone hits. Teens and 20s as well as low 40s and IF junk will usually go “ker-chunk” or jump numbers by five or more. Zincolns hit pretty consistent as do the bigger rings. Another factor is the karat rating, that seems to bend the basic rules a bit.
Basically it can possibly be any number between 5 and 50 lol
If you never dig all you will never know all the possibilities just probabilities
I think if you surveyed every detectorist and asked what number jewelry came in as, it would probably cover the entire spectrum.
Just hunting in general for whatever you can afford some leeway but specifically looking for something will you chance not digging a signal.
I suppose a good example would be law enforcement looking for a piece of evidence in a specific area. Would they say, no i don’t like the number that gave so im going to skip it.