A diamond necklace-tiara, circa 1890. Photo Bonhams

The chain of old brilliant-cut diamonds in box collet settings, suspending a similarly set radiating fringe alternating with foliate motifs, on a knife-edge back-chain with diamond trefoils, diamonds approximately 16.75 carats total, cased by Cartier, tiara frame supplied, length 37.5cm. Estimate: £12,000 - 18,000, US$ 19,000 - 29,000

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