I've read your post, just debating how to answer.
If gold and silver isn't there to find you just are not going to find it. But typically, silver is going to read above 60. If you are recovering copper pennies, dimes and quarters you would have also found a silver ring or coin if it was there. Most girls/womens small gold rings are going to read from about 20 to 26. That is the foil range. Mens rings are going to read from about 32 to 50. That is the tab range. Some rings may read as high as 60 (like a zinc penny) Noticed I said "typically", There is a lot of variation and they can read all over based upon size and content. For the numbers I have posted, others may come back and say they found a ring at 18 and 30. But those numbers are good starts.
Just keep beeping away and things will click.
Hope that helps,
HH
Mike