Fist of all Congrats for your finds! As i look at this beautiful picture with those gold rings something went through my mind. Did you find all those rings in same area or just part of it on the same spot? Those big rings with black enamel or stone look very similar as i can notice, and also those two with an inscription at the bottom of the picture.
If they are found at the same spot, the "black" ones espacially, or the other two i mentioned they might be from a crime scene, just saying, or somebody lost all of his rings while swimming, you never know. Maybe is a good idea to check with the local police, looks like somebody lost an arm not a ring.