There's definitely a spiral design on one side - you can really see it in the picture with the flash. It measures .60 inch in diameter and it's 3.1 mm thick. Is it old or is it junk?
Could be a gold-washed 1-piece cast pewter (or 20th Century "potmetal") button with the thin cast shank broken off. In that corroded condition, I can't be sure whether it is from the 1700s or the 1900s.
Could be a gold-washed 1-piece cast pewter (or 20th Century "potmetal") button with the thin cast shank broken off. In that corroded condition, I can't be sure whether it is from the 1700s or the 1900s.