This is a gorgeous vintage black silk millinery flower that could be worn as a dress brooch - you’d just have to attach a safety pin.  Or you could add it to a hat, either an existing hat or a new creation.  It measures about 6 1/2” in diameter and is in very good condition.  It probably dates to the 1930s or 40s.  Striking and unusual - you don’t often see black silk flowers…….