A magnificent diamond pendant. The princess-cut diamond surmount terminating in a pear-shaped diamond, weighing 14.36 carats, suspended from a snake-link chain, pendant length 3.0cm. Estimate: £200,000 - 250,000. photo courtesy Bonhams

A magnificent 14.6 carat diamond pendant expected to fetch £200,000 - 300,000 is to be sold at Bonhams, New Bond Street as part of its first Fine Jewellery sale of the year on 21st April 2010. It's accompanied by a certificate from GIA stating that the pear modified brilliant-cut diamond is very light pink, natural colour, internally flawless clarity. Certificate number 5111665223, dated 12th February 2010.

The sale also features four single stone diamond rings 5.05 carats, E colour, loupe clean, accompanied by a certificate from GIA stating that the diamond is D colour, VS1 clarity. Certificate number 2115845854, dated 19th March 2010;

5.01 carats, D colour, VS1 clarity, accompanied by a certificate from GIA stating that the diamond is D colour, VS1 clarity. Certificate number 2115845854, dated 19th March 2010;

4.74 carats, D colour, VVS1 clarity, accompanied by a certificate from GIA stating that the diamond is D colour, VVS1 clarity. Certificate number 5111614539, dated 27th January 2010;

and 5.03 carats, G colour, internally flawless, accompanied by a certificate from GIA stating that the diamond is G colour, internally flawless clarity. Certificate number 5111614537, dated 27th January 2010; and accompanied by a certificate from De Beers, stating that the diamond is F colour, internally flawless clarity. The diamond is laser-numbered D26C 1011 respectively.

A diamond single-stone ring. The marquise-cut diamond, weighing 5.05 carats, between trillion-cut diamond shoulders, ring size M½, cased. Estimate: £60,000 - 80,000. photo courtesy Bonhams

An impressive diamond single-stone ring. Claw-set with a brilliant-cut diamond, weighing 5.01 carats, within a four-claw setting, ring size M. Estimate: £80,000 - 100,000. photo courtesy Bonhams

An impressive diamond single-stone ring. Set with a brilliant-cut diamond, weighing 4.74 carats, within an eight-claw setting, ring size L. Estimate: £100,000 - 150,000. photo courtesy Bonhams

An impressive diamond single-stone ring, by De Beers. The step-cut diamond, weighing 5.03 carats, within a four-claw platinum setting, the interior hoop set with a 'secret' brilliant-cut diamond highlight, signed De Beers, maker's mark, numbered, Birmingham hallmark, ring size H, maker's case and presentation box. Estimate: £55,000 - 65,000. photo courtesy Bonhams

It follows Bonhams Jewellery Department's most successful year ever in 2009 which finished with the December 9 sale - The Art of Jewels: Fine Jewellery and Iconic Gems - in which a natural pearl necklace once belonging to Lady Houston fetched £311,200.

The first sale of fine jewellery in 2010 hopes to imitate this success. Jean Ghika, Director of Bonhams Jewellery Department, says: "We are delighted to be handling such a selection of exceptional diamonds, with estimates ranging from £55,000 – 300,000, as well as a number of rare Art Deco period pieces, for which competition is expected to be fierce."

Of particular interest is a silver gilt paste and gem-set collar necklace which is similar to the work of the 20th century jeweller Sah Oved. It is expected to fetch £3,000 – 5,000. The openwork collar of neo-Gothic gilded tracery, set to the centre with a row of red paste and silver Tudor roses, the largest to the centre within a quatrefoil frame, suspending a graduating fringe of smokey and rose quartz crystals, each with a cap of stylised foliate and beadwork decoration, alternating with lapis lazuli beads and drop-shaped pendants, unmarked, length 44.5cm., handmade fitted case. This necklace is comparable to the work of the 20th century British jeweller, Sah Oved (1900-1983) who was responsible for some of the most original and striking designs created before the Second World War. Of particular note is the pioneering use of rough crystals which was also a feature of Sah's early work. The silver leaves set with red paste are similar in execution to those on a silver cross, made by Sah Oved, around 1920.

A rare silver gilt, paste and gem-set collar necklace, circa 1920. Estimate: £3,000 - 5,000. photo courtesy Bonhams

Other unique lots include an Art Deco diamond bracelet by Lacloche Frères, circa 1925 (estimate £6,000 – 8,000) designed as an articulated series of openwork oblong plaques, interlaced with navette-shaped connecting links, each with a collet-set old brilliant-cut diamond at the centre, millegrain-set throughout with old brilliant and single-cut diamonds, diamonds approximately 8.00 carats total, signed Lacloche Fres, numbered, maker's mark, French assay mark, length 18.9cm.

An art deco diamond bracelet, by Lacloche Frères, circa 1925. Estimate: £6,000 - 8,000. photo courtesy Bonhams

and a Van Cleef & Arpels Art Deco diamond, emerald and onyx bracelet (estimate £15,000 – 20,000), delicately pierced strap composed of a series of articulated links set with courses of single-cut diamonds and square-cut emeralds in woven geometric formation, surrounded by borders of calibré-cut onyx, with millegrain detail throughout and carved scrolled decoration to the gallery of each link, diamonds approximately 4.50 carats total, signed Van Cleef & Arpels, numbered, partially indistinct maker's mark, French assay mark, length 19.3cm.

An art deco diamond, emerald and onyx bracelet, by Van Cleef & Arpels, circa 1925. Estimate: £15,000 - 20,000. photo courtesy Bonhams