The pin is signed on the back with a small sized upper case “A” and a much larger “S”. I haven’t been able to identify the maker’s mark, but I’m assuming it is an American piece. It is circa 1900-1950, and the time period between 1920-1940 is most likely.
The pin measures 2 1/8” long x 5/8” wide. It is both sturdy & lightweight. The stick pin appears to be gold, as well, and fastens by way of a C loop with a safety latch. This was the precursor to the modern, rolling/locking C clasp, and this helps in dating this piece.