By Ase Anderson in London
A rare and extraordinary diamond ring by Piaget is set to be the undisputed star of Bonhams Fine Jewellery Sale in London this month.
Boasting both excellent clarity (VVS2) and the top colour grade for white diamonds, the 8.97 carat marquise-cut stone is expected to fetch in the region of £250,000-£350,000. The high quality of the ring is further enhanced by the fact that the diamond has been classified as chemically pure and given a Type IIa grading by the GIA.
The desire for coloured gems among collectors shows no sign of diminishing and this time all eyes will be on two rings featuring a Colombian emerald and a Burmese sapphire, respectively.
Described as being of "exceptional colour", the 10.49 carat emerald is estimated to sell for £150,000-£200,000. A similar top price is predicted for the cushion-cut sapphire ring, which also features two demi-lune shaped diamonds.
Other top lots at the sale, which is taking place at New Bond Street on 30 April 2014, include a step-cut Fancy Yellow diamond ring weighing an impressive 24.59 carats.
Period jewellery buffs will have their appetite sated by a rare and colourful 'Orange Tree' brooch, dating back to 1914. Made by Cartier, the miniature orange tree, complete with three cabochon ruby 'fruits', is said to "exemplify early 20th century quality and innovation".