An Edwardian opal and diamond brooch

An Edwardian opal and diamond brooch, the oval cabochon-cut opal measuring approximately 14.3 x 11mm, yellow gold claw-set to the centre of an old-cut diamond cluster surround, all within a border of old-cut diamond sprays forming a quatrefoil design, all diamonds millegrain-set in silver to a yellow gold mount, with detachable brooch fitting and diamond-set pendant loop, circa 1900, gross weight 8.7 grams

No. 23194M