A crystal opal and diamond antique brooch. 15ct yellow gold, hallmarked Australian, presented as a bar brooch style piece, centred by an oval cabochon crystal opal of strong spectral colours, measuring approximately 11 x 9 mm, framed by smaller old cut diamonds, seventeen stones totalling approximately 0.68ct, branching outward to fine gold arms with scrolled ends and single smaller cabochon opals set in kite frames, fitted with pin to reverse