A fire opal and diamond cluster ring. Photo: Bonhams. The raised oval mixed-cut fire opal, weighing 5.64 carats, within a brilliant-cut diamond surround, ring size M½. Estimate £2,500 - 3,500 (€3,000 - 4,300) Accompanied by a report from The Gem & Pearl...

A fire opal and diamond ring, circa 1905. Photo: Bonhams. The large step-cut fire opal, within single and rose-cut diamond-set lotus flower claws, ring size Q. Estimate £800 - 1,200 (€970 - 1,500) Bonhams. JEWELLERY. 12 Feb 2014, London, Knightsbridge...