An Antique Emerald and Diamond Brooch, late 19th Century. photo: Christie's Images Ltd 2012

Of square shape, centering upon a square-cut emerald, to the old-cut diamond openwork surround, mounted in silver and gold, 3.3 cm. Estimate CHF28,000 - CHF46,000 ($30,792 - $50,587)

Christie's. Jewels for Hope: The Collection of Mrs Lily Safra 14 May 2012 Geneva