copper object

[jefg231]

front decorative part is copper, back seems to be junk metal. Any thoughts?

 

[sagittarius98]

Possibly a button or pin.

 

[TheCannonballGuy]

It is a civilian horse-harness rosette. The particular type you found (iron back) dates from the latter 1800s into the early 20th-century. Your rosette was attached to the leather harness by a large staple-shaped iron wire, the middle section of which is broken off on your rosette.