An early 20th century black opal and diamond brooch, the quarter-segment-shaped flat cabochon black opal millegrain collet set within a spaced surround of individually millegrain set old brilliant-cut diamonds, to an outer hoop surround of similarly set single-cut diamonds, mounted in yellow and white precious metal, opal measures 19mm high x 22mm wide, brooch width 31.5mm. £3000-5000

See front cover illustration.