Lot 126. A 3.81 carats fancy intense blue diamond ring. Sold for £2,322,500 (€2,702,938). Photo: Bonhams.

LONDON - Bonhams kicks off the fine jewellery autumn season selling Kashmir sapphires, Harry Winston diamonds and signed jewellery for dazzling prices.

A rare blue diamond and pair of Kashmir sapphires caught the eye of global buyers at Bonhams Fine Jewellery sale this week (20th September 2016).

The star of the sale was a very rare oval-cut blue diamond. Weighing 3.81 carats, the Fancy Intense Blue diamond hails from a private British collection and sold for £2,322,500 ($792,450 per carat).

Jean Ghika, Head of Jewellery for Bonhams UK & Europe, explains: "Blue diamonds account for only 0.004% of all diamonds mined and are therefore exceptionally rare and remain highly sought after. The price achieved in today's auction demonstrates that the global appetite for coloured diamonds remains as buoyant as ever."

Bonhams has an impressive track record in selling blue diamonds and holds two price-per-carat world auction records: for a Fancy Deep Blue diamond at $1.77m per carat, and a Fancy Greyish-Blue diamond at $730,000 per carat.

Lot 126. A 3.81 carats fancy intense blue oval-cut diamond ring. Sold for £2,322,500 (€2,702,938). Photo: Bonhams.

Accompanied by a report from GIA stating that the diamond is Fancy Intense Blue, natural colour, I1 clarity. Report number 2173507045, dated 4 March 2016.

Blue was certainly all the rage in the sale with the second headline lot, an exceptional pair of late 19th century Kashmir sapphire earrings. Weighing 8.97 and 8.93 carats, the sapphires were fiercely contested and finally sold for £866,500 (or $62,900 per carat) against their pre-sale estimate of £400,000-600,000. 

Lot 125. A pair of late 19th century 8.97 and 8.93 carats Kashmir sapphire and diamond cluster earrings. Sold for £866,500 (€1,008,437). Photo: Bonhams.

The cushion-shaped sapphires, weighing 8.97 and 8.93 carats, each within a surround of old brilliant-cut diamonds, with an old brilliant-cut diamond surmount, converted from a late 19th century jewel, diamonds approximately 4.20 carats total, earring length 3.7cm

Accompanied by a report from SSEF stating that the sapphires are of Kashmir origin, with no indications of heating. Report number 85864, dated 12 May 2016.

Accompanied by a report from AGL stating that the sapphires are of Kashmir origin, with no indications of heating. Report number CS 1075004 A and B, dated 13 April 2016.

Accompanied by older reports from SSEF and Edelsteinbefundbericht.

Diamonds perform strongly
White diamonds were also in demand at Bonhams during the three-hour sale which achieved £6,440,200, with 92% of lots sold by value.

Much admired during previews in Hong Kong, Geneva, London and New York, a top quality 11.00 carat Marquise-Cut Diamond performed extremely well. The D colour, VS1 clarity, Type IIa stone, was also one of the sale's highest performers selling for £614,500 against an estimate of £200,000-250,000.

 Lot 124. A 11.00 carat D colour, VS1 clarity, Type IIa marquise-cut diamond  single-stone ring. Sold for £614,500 (€715,158). Photo: Bonhams.

Accompanied by a report from GIA stating that the diamond is D colour, VS1 clarity. Report number 2171646461, dated 24 May 2016.

Accompanied by an additional letter from GIA stating that the diamond has been classified as Type IIa.

Elsewhere, a Diamond single-stone ring, by J. Roca, was also hotly contested. The brilliant-cut 13.77 carats diamond hammered for £302,500 against its estimate of £180,000-250,000. 

Lot 120. A 13.77 carats diamond single-stone ring, by J. Roca. Sold for £302,500 (€352,051). Photo: Bonhams.

Accompanied by a report from GIA stating that the diamond is I colour, VVS2 clarity. Report number 5172646445, dated 24 May 2016.

Two diamond lots signed by the King of Diamonds himself, famed American jeweller Harry Winston, also generated considerable interest. The first, a pair of Harry Winston Diamond Earclips, weighing approximately 34.00 carats of diamonds, sold for £80,500, and the second, a Harry Winston Diamond Necklace with 38.00 carats of marquise and pear-shaped diamonds, sold for £110,500. 

Lot 122. A pair of approximately 34.00 carats diamond earclips, by Harry Winston. Sold for £80,500 (€93,686). Photo: Bonhams.

Please note that the diamonds are approximately 33.60 carats total, not 45.30 carats total as stated in the catalogue.

Lot 123. A diamond necklace, by Harry Winston. Sold for £110,500 (€128,600). Photo: Bonhams.

A pair of antique diamond earrings, circa 1830, also attracted competitive bidding. The old cut diamonds, weighing 3.02 and 3.25 carats, classified as Type IIa, probably hailed from the famed Golconda mines and sold for £104,500 against a pre-sale estimate of £30,000-40,000.

Lot 109. A pair of 3.02 and 3.25 carats Type IIa diamond pendent earrings, circa 1830. Sold for £104,500 (€121,617). Photo: Bonhams.

Accompanied by a report from GIA stating the diamond weighing 3.02 carats is E colour, SI2 clarity. Report number 5171646556, dated 24 May 2016.

Accompanied by a report from GIA stating that the diamond weighing 3.25 carats is F colour, SI2 clarity. Report number 5171646553, dated 24 May 2016.

Accompanied by additional letters from GIA stating that the diamonds weighing 3.02 and 3.25 carats have been classified as Type IIa.

In line with the ongoing demand for coloured stones, the sale also featured an impressive Emerald and diamond cluster ring, circa 1960. The cushion-shaped emerald, weighing 12.50 carats, of Colombian origin, sold for £69,700 against its estimate of £30,000-40,000.

Lot 90. A 12.50 carats Colombian cushion-shaped emerald and diamond cluster ring, circa 1960. Sold for £69,700 (€81,117). Photo: Bonhams.

Accompanied by a report from SSEF stating that the emerald is of Colombian origin, of medium strong saturation with a minor amount of oil in the fissures. Report number 86334, dated 16 June 2016.

Design-led jewellery in demand
A rare piece from the 1970s by Andrew Grima, the doyen of modern jewellery design in Britain, also performed well at the auction. The gold gem-set and diamond bracelet, dated 1973, features carved emeralds and cabochon sapphires of various sizes, mounted in 18 carat gold, interspersed with brilliant-cut diamond accents, sold for £23,750. 

Lot 44. A gold, gem-set and diamond bracelet, by Andrew Grima, 1973. Sold for £23,750 (€27,640). Photo: Bonhams.

Note: This bracelet was exhibited at the Grima 'Retrospective' exhibition at Goldsmiths' Hall in 1991. See exhibition catalogue number 246, page 86.

Jean Ghika, Head of Jewellery for Bonhams UK & Europe, says: "With participation from our global client base, these results, particularly for blue diamonds, Kashmir sapphires and top quality white diamonds demonstrate the market is buoyant for the very best items."