A gold, paste and enamel 'memento mori' ring, 1727. Photo Bonhams

The coffin-shaped bezel depicting the image of a skeleton, overlaid with a similarly shaped transparent paste in a collet setting, another skeleton curving round the hoop rendered in black enamel with a crown at its head and the legend 'memento mori' at its feet, the interior inscribed with the initials 'JB' and the date '1727', ring size Q. Estimate: £2,000 - 3,000, US$ 3,200 - 4,800 

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