This pin, while marked "9 ct" is not hallmarked by its maker, so its exact date is uncertain. However, there are some clues. The old style, T bar hinged pin, which extends well beyond its simple, C style catch, tells us that this is an early to mid 19th c piece, worn when thicker garments were the norm.
This finely detailed brooch, while showing subtle marks of wear, commensurate w its age, is in remarkably good condition for its age. It measures approx 1" x 1.75".