A late 19th century opal and diamond-set gold bangle, set with a central oval solid white opal

A late 19th century opal and diamond-set gold bangle, set with a central oval solid white opal within a cushion-shaped diamond surround, on trifurcated shoulders set with further old cushion-shaped diamonds in silver and gold, the central oval section detaches from the bangle to be worn as a brooch, length of opal and diamond cluster 3cm, internal bangle width 5.4cm, with gold brooch fitting, case