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A fancy-coloured diamond single-stone ring. Photo Bonhams

Photo BonhamsThe cushion-shaped diamond, weighing 7.15 carats, set as a lozenge, within an eight-claw setting, ring size O (photographed unmounted) - Estimate: £30,000 - 40,000, US$ 49,000 - 65,000

Accompanied by a certificate from GIA stating that the diamond is fancy intense yellow, natural colour, SI1 clarity. Certificate number 2135751017, dated 19th August 2011.

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A fancy-coloured diamond dress ring. Photo Bonhams

The radiant-cut diamond, weighing 5.68 carats, within a brilliant-cut diamond border, to similarly cut diamond gallery and shoulders, diamonds approximately 0.85 carat total, ring size M - Estimate: £25,000 - 30,000, US$ 41,000 - 49,000

Accompanied by a GIA certificate stating that the diamond is natural fancy yellow, SI1 clarity. Certificate number 1132338143, dated 21st April 2011.

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A pair of diamond and fancy-coloured diamond pendent earrings. Photo Bonhams

Each articulated line surmount, suspending an annular pendant with a central tassel motif, terminating in an articulated fringe, set throughout with brilliant and pear-shaped diamonds, of yellow, pink and near colourless tint, diamonds approximately 10.50 carats total, diamonds untested for natural colour, length 7.0cm - Estimate: £10,000 - 15,000, US$ 16,000 - 25,000

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A diamond and fancy-coloured diamond crossover ring, by Graff. Photo Bonhams

Set with a heart-shaped diamond, weighing 1.14 carats, and a heart-shaped diamond of yellow tint, weighing 1.24 carats, to a bi-coloured band, signed Graff, diamond untested for natural colour, ring size I½, maker's case - Estimate: £10,000 - 15,000, US$ 16,000 - 25,000

Bonhams. Fine Jewellery, 21 Sep 2011. New Bond Street www.bonhams.com