This is a fantastic vintage Art Deco chatelaine drop brooch in sterling silver, marcasite and onyx. The pin is reticulated or hinged so that it moves. It features a monogram of FHD in the bottom section and the pin back fastens with a trombone catch, which indicates that it is most likely European in origin. It dates to around the 1920s or 30s. It is unmarked but has been acid tested for sterling silver and the stones have been tested with a gemstone tester.
It measures about 2 1/4 inches by about 1 1/8 inches and it is in very good condition.