Bonhams kicked off its fine jewellery autumn season in London yesterday, selling a rare blue diamond, Kashmir sapphires, Harry Winston diamonds and signed jewellery for dazzling prices.

The sale achieved a total of £6.44 million ($8.36 million) with 92 per cent of lots sold by value.

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 £2.32 million ($3.01 million/$792,450 per carat).

Jean Ghika, Head of Jewellery for Bonhams UK & Europe, explains: “Blue diamonds account for only 0.004 per cent of all diamonds mined and are therefore exceptionally rare and remain highly sought after. The price achieved 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 $1.77 million per carat, and a fancy greyish-blue diamond at $730,000 per carat.

Blue was certainly all the rage in the sale with the second headline lot, an exceptional pair of late 19^th century Kashmir sapphire earrings. Weighing 8.97 and 8.93 carats, the sapphires were fiercely contested and finally sold for £866,500 ($1.12 million or $62,900 per carat) against their pre-sale estimate of £400,000-600,000.

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 ($797,700) against an estimate of £200,000-250,000.

Elsewhere, a diamond single-stone ring by J Roca was also hotly contested. The brilliant-cut 13.77-carat diamond hammered for £302,500 ($392,700) against its estimate of £180,000-250,000.

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 ($105,000), and the second, a Harry Winston diamond necklace with 38.00 carats of marquise and pear-shaped diamonds, sold for £110,500 ($143,500).

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 ($135,500) against a pre-sale estimate of £30,000-40,000.

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 ($90,500) against its estimate of £30,000-40,000.

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-karat gold, interspersed with brilliant-cut diamond accents, sold for £23,750 ($33,800).

Ghika 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.”

Bonhams's autumn fine jewellery season continues with a New York Fine Jewellery sale on October 14, a Hong Kong Rare Jewels and Jadeite sale on November 30 and a London Fine Jewellery sale on December 4 this year.