Youtuber DallMYD takes a scuba diving excursion to the bottom of a Georgia river. While there he discovers a treasure trove of jewelry.
DallMYD mentions that when he finds fishing lures he learns a lot about how other fishermen work. He learns a lot about being an angler from these lures, and a lot of those he finds can be cleaned up and given to kids he knows so that they can practice fishing.
The jewelry he discovered looks to be high-quality costume jewelry, the sort that your grandmother might have worn. My guess is that someone recently planted it in the river for a scuba diver to find, as they are mostly elastic pieces no one would actually wear, and the elastic is still stretchy on the rings he puts on.