This is a Vintage 9k gold plated "Lucky 7" horse shoe brooch w a detailed floral pattern in subtle rose & green gold plate. The center "flower" sports a sparkling CZ "diamond" which our jeweler added, as the original stone was missing.
The more modern, rolling & locking C clasp & hinged pin date this pretty pin at around 1910-1940. It measures approx 1" x 1". Diamonds (& CZ's) look good w any outfit and particularly nice on a dressage stock.