This Belle Epoque openwork 18K gold brooch is finely modeled as a royal crown embellished with pearls, old mine and rose cut diamonds.
The three principal diamonds are bright white (E-F color) old mine cut stones with approximate weight of 0.23 ct, 0.19 ct, 0.17 ct (VS1, VS2, SI2 clarity).
Estimated total diamond weight is 1.06 carat.
Length 55 mm (2 3/16 in.)
Height 29 mm (1 1/8 in.)
The brooch is almost certainly a royal presentation piece.