This specimen was found on a site that has produced artifacts from the Civil War. The material is unknown, but patinated like brass while retaining a aluminum or stainless like gloss. This appears to be an eagle facing left without a shield against a lined field. On the back, stars are visible above the eagle’s head. It measures 34.5mm in diameter. Initial thought was a bridle boss, but have not seen a similar example. Purpose, age, other examples appreciated.