Late 19th century diamond crescent brooch

Late 19th century diamond crescent brooch, thirteen graduated old mine cut diamonds and two rose cut diamonds, the principal diamond measuring approx 4.02mm x 4.18mm x 2.41mm, weighing approx 0.25 carat, calculated total diamond weight approx 1.60 carats, assessed clarities SI, assessed colours I-K, unmarked yellow metal and silver, hinged pin and simple loop brooch fittings, dimensions approx 2cm x 2cm, 3.6g gross approx, boxed