I found this in an area that was a training ground during the Civil War and then was turned into a fairground until about the 1940's. Now a portion of it is a tot lot and the rest is a high school. It's finished just enough to possibly be an inexpensive man's ring but that seam in it makes me wonder if it was part of a gas or oil lantern. It is the size of a small man's or larger woman's ring and is brassy in appearance. Any guesses?