A diamond necklace-tiara, circa 1880. Photo Bonhams

The necklace composed of a series of collet-set old brilliant-cut diamonds, suspending a fringe of knife-wire and foliate motifs, set throughout with old brilliant-cut diamonds to a later knife-edge back-chain set with rose-cut diamond highlights, diamonds approximately 16.65 carats total, length 38.5cm. Estimate: £20,000 - 25,000, US$ 32,000 - 40,000. Unsold

Bonhams. Fine Jewellery, 25 Apr 2012. London, New Bond Street www.bonhams.com