A black opal and diamond brooch

A black opal and diamond brooch, the solid black opal cabochon is set within a graduated border of alternately-set baguette-shaped and circular-cut diamonds in white gold, 3.8cm wide

Accompanied by report number E15880 dated 6 December 2013 from Nederlands Edelsteen Laboratorium stating that the half moon-shape cabochon opal measures 23 x 11.3 x 5.5mm and is a natural black opal