An emerald single-stone ring. Photo: Bonhams.

The large step-cut emerald between triangular-cut diamond shoulders, emerald approximately 16.10 carats, diamonds approximately 2.50 carats total, ring size N. Estimate £12,000 - 18,000 (€15,000 - 22,000)

Bonhams. FINE JEWELLERY. London, New Bond Street, 30 Apr 2014 - www.bonhams.com