Lot 667. Fancy coloured diamond and diamond earrings. Photo: Bonhams.

NEW YORK - A rainbow of coloured gemstones along with rare signed jewellery pieces are to be offered at Bonhams forthcoming jewellery sale this November. 
 
In its last sale of the year, Bonhams Rare Jewels and Jadeite sale is set to feature more than 160 lots estimated in excess of HK$100 million. 

The rainbow of coloured stones up for auction include: 

· Red: A 4.02 carats cushion-shaped ruby and diamond dress ring. Estimated at HK$1,350,000 - 1,800,000 (). 

Lot 647. A fine 4.02 carats cushion-shaped 'Pigeon's Blood' Burma ruby and diamond dress ring. Estimate HK$1.35 million - 1.8 million (€160,000 - 210,000). Unsold. Photo: Bonhams.

The cushion-shaped ruby, weighing 4.02 carats, beside an oval-cut diamond floral cluster, accented by a circular-cut ruby stamen, completed by a half hoop set with brilliant-cut diamonds, diamonds approximately 3.35 carats total, ring size 6½ 

Accompanied by a GIA report stating that the 4.02 and 0.19 carat natural 'Pigeon's Blood' rubies have no indication of thermal treatment and originate from Burma (Myanmar). Report number 2194967528, dated 7 May 2015.

· Orange / yellow: a pair of floral earrings set with cushion-shaped, fancy vivid yellow orange and yellowish orange diamonds (estimated at HK$2,800,000 - 3,800,000). 

Lot 667. A pair of floral earrings set with cushion-shaped, fancy vivid yellow orange and yellowish orange diamonds. Estimate HK$2,800,000 - 3,800,000 (€330,000 - 450,000). Sold for HK$ 3,160,000 (€ 375,439). Photo: Bonhams.

Each floral earring centring a radiant-cut fancy vivid yellowish orange diamond weighing 2.87 carats, and a radiant-cut fancy vivid yellow-orange diamond weighing 2.53 carats, within a brilliant-cut diamond petal surround, diamonds approximately 7.80 carats total, length 3.0cm 

Accompanied by a GIA report stating that the 2.87 carat diamond is natural Fancy Vivid Yellowish Orange colour. Report number 17481719, dated 14 October 2008.

Accompanied by a GIA report stating that the 2.53 carat diamond is natural Fancy Vivid Yellow-Orange colour. Report number 16286425, dated 14 August 2007. 

According to the Gemmological Institute of America (GIA), only one in ten thousand diamonds classify as fancy coloured diamonds outside the normal D - Z colour range. Colour in diamonds is caused by the intrusion of an impurity into the diamond's carbon crystal structure during formation. A diamond is coloured according to the type and number of impurities introduced. Nitrogen impurities are the cause of yellow and orange coloured diamonds. 

It is believed that the world's first diamond colour grading system dates back to sixth-century India. In the present day, fancy coloured diamonds are graded according to a number of factors, the most important being colour and colour intensity known as 'saturation'. 

Orange diamonds very seldom occur in nature and are considered among the most rare of fancy coloured diamonds. 
An average estimate indicates that mines produce coloured diamonds at a rate of 1-2 carats for every 3000 carats mined. Of those 85% are either yellow or brown. The other colours like orange, pink, red and blue are far more rare.

According to the GIA, as the colour appearance of strongly coloured diamonds transitions from orangy yellow to orange, the occurrence of these diamonds becomes progressively more rare. The less yellow present, the more rare the diamond. Vivid orange and vivid yellowish orange diamonds are the most rarely occurring, and are often referred to as 'pumpkin' diamonds.

The present lot is composed of two diamonds certified by the GIA as fancy yellowish orange and fancy yellow-orange. Importantly, these grades indicate that orange is the predominant hue in each diamond. Furthermore, both diamonds are impressively graded as being of a vivid saturation, suggesting that they are both of the strongest saturation that can be attributed to any fancy coloured diamond. This lot presents the rare opportunity to possess a pair of very closely matched, vividly saturated diamonds of predominantly orange hue.

· Green: a 14.93 carats cornered step-cut, Colombian emerald and diamond ring (estimated at HK$3,000,000 - 4,000,000). In addition, the auction house will also offer a fine translucent carved jadeite ‘Guanyin’ of a rich bright green colour, meditating on a lotus throne, embellished by marquise, pear and brilliant-cut diamonds (estimated at HK$2,700,000 - 3,500,000). 

Lot 666. An important 14.93 carats cornered step-cut, Colombian emerald and diamond ring. Estimate HK$ 3 million - 4 million (€350,000 - 470,000). Unsold. Photo: Bonhams.

The cut cornered step-cut emerald, weighing 14.93 carats, set between tapered baguette-cut diamonds,ring size 5¾

Accompanied by an AGL (American Gemological Laboratories) report stating that the the natural emerald has no indication of clarity enhancement and originates from Colombia. Report number CS 55365, dated 10 September 2014.

Lot 625. A fine translucent carved jadeite ‘Guanyin’ of a rich bright green colour, meditating on a lotus throne, embellished by marquise, pear and brilliant-cut diamonds pendant. Estimate HK$ 2.7 million - 3.5 million (€320,000 - 410,000). Unsold. Photo: Bonhams.

The fine translucent carved jadeite 'Guanyin' of a rich bright green colour, measuring approximately 62.4 x 41.8 x 6.0mm meditating on a lotus throne, embellished by marquise, pear and brilliant-cut diamonds, diamonds approximately 7.60 carats total, length 8.5cm 

Accompanied by a Hong Kong Jade & Stone Laboratory report stating that the natural colour fei cui (jadeite jade) has no resin detected. Report number KJ 91280, dated 10 September 2015.

· Blue: a 6.50 carat square step-cut Kashmir sapphire and diamond ring (estimated at HK$5,800,000 - 7,000,000). The auction house is also offering a 26.43 carats sapphire and diamond ring (estimated at HK$4,800,000-5,800,000). 

Lot 653. An important 6.50 carat square step-cut Kashmir sapphire and diamond ring. Estimate HK$ 5.8 million - 7 million (€680,000 - 820,000). Unsold. Photo: Bonhams.

The square step-cut sapphire, weighing 6.53 carats, between cushion-shaped diamond shoulders, weighing 2.65 carats total, ring size 6

Accompanied by an AGL (American Gemological Laboratories) report stating that the natural sapphire has no indication of thermal treatment and originates from Kashmir. Report number CS 85035, dated 29 September 2015.

Accompanied by a SSEF report stating that the natural sapphire has no indication of thermal treatment and originates from Kashmir. Report number 82202, dated 25 September 2015.

Accompanied by two GIA reports stating that the 1.33 and 1.32 carat diamonds are E colour, VVS2 and VVS1 clarity. Report numbers 6191722547 and 1166844187, dated 26 March 2015 and 8 December 2014.

· Purple/pink: A 9.21 carats pear-shaped fancy light purplish pink, Internally Flawless, Type IIA, diamond pendant (estimated at HK$12,000,000 - 15,000,000) and a rare oval-cut fancy vivid purplish pink, VVS1 clarity, diamond ring (estimated at HK$4,500,000 - 7,000,000).

Lot 669. An important 9.21 carats pear-shaped fancy light purplish pink, Internally Flawless, Type IIA, diamond pendant. Estimate HK$2,800,000 - 3,800,000 (€330,000 - 450,000). Sold for HK$ 13,240,000 (€ 1,573,044). Photo: Bonhams.

The pear-shaped fancy light purplish pink diamond, weighing 9.21 carats, suspended from a chain necklace accented by brilliant-cut diamonds of purplish pink tint and similarly cut colourless diamonds, remaining diamonds and coloured diamonds approximately 3.15 carats total, chain length 42.0cm

Accompanied by a GIA report stating that the diamond is natural Fancy Light Purplish Pink colour and Internally Flawless. Report number 2165972979, dated 12 February 2015.

Also accompanied by an appendix from GIA stating that the diamond is Type IIa and therefore chemically pure.

Lot 668. A 1.11 carats fine oval-cut fancy vivid purplish pink, VVS1 clarity, diamond ring by Harry Winston. Estimate HK$4,500,000 - 7,000,000 (€530,000 - 820,000). Sold for HK$ 3,880,000 (€ 460,982). Photo: Bonhams.

The oval-cut fancy vivid purplish pink diamond, weighing 1.11 carats, between pear-shaped diamonds, signed HW, ring size 5¾, with original box

Accompanied by a GIA report stating that the diamond is natural Fancy Vivid Purplish Pink colour and VVS1 clarity. Report number 11568335, dated 6 July 2001.

Jewellery collectors will also be delighted to find a rare and impressive enamel, emerald and diamond ‘Serpenti’ bracelet watch by Bulgari, circa 1970 among the highlights. It is believed that Bulgari produced less than 100 of the iconic ‘Serpenti’ bracelet watches between 1960 and 1970. The late Hollywood actress Elizabeth Taylor – who was known for her love of fine jewellery - played an important role in propelling the Bulgari snake bracelet into the spotlight when she was photographed wearing one on the set of Cleopatra in 1962. 

Lot 650. A rare enamel, emerald and diamond 'serpenti' bracelet watch, by Bulgari, 1970. Estimate HK$1.2 million - 1.5 million (€140,000 - 180,000). Unsold. Photo: Bonhams.

The articulated sprung wrap-around bracelet designed as a serpent with white enamel scales, accented by brilliant-cut diamonds, the eyes set with pear-shaped emeralds, the head set with a hinged cover to reveal a round silver dial, gilt baton hour makers and black Arabic quarters, mechanical movement by LeCoultre, signed Bulgari, dial and movement signed Le Coultre, diameter 3.5cm, fitted case by Bulgari

Accompanied by a letter of authenticity.

Notes: The Serpenti collection of jewellery and watches is unequivocally an icon of Bulgari design. The earliest Serpenti collection pieces can be traced back to the 1940s, in the form of tubogas snake bracelets. Some twenty years later, the late Elizabeth Taylor helped propel the Bulgari snake bracelet into the spotlight when she was photographed wearing one on the set of Cleopatra in 1962. Her bracelet became a celebrated example of the original snake bracelets designed by Bulgari from 1950 until 1970.

According to Marion Fasel in her book 'Bvlgari Serpenti Collection' (Assouline, 2013), early Serpenti bracelets were designed with a white gold spring inside the body, and a flexible outer band allowing the bracelet to cling gently to its wearer's wrist. In the early versions, scales tended to be engraved, and either overlapping as gold bands of pentagonal in structure. The snakes were decorated with various gems set into the eyes, and forked tongues extending just beyond the mouth. Like the present example, the hinged jaws opened to reveal a circular watch with a swiss movement by Jaeger-LeCoultre. Each piece represented a unique model, displaying varied details and accents.

During the mid 1960s, enameled versions began to emerge. Similarities, however, between these versions and those of the 1940s and 1950s remained, with motifs of gem-set details, forked tongues and round watch faces incorporated into the updated designs. Bulgari partnered with Jaeger-LeCoultre and Vacheron Constantin on the movements for the watch mechanisms. The present lot bears these characteristics, suggesting that its manufacture took place in the late 1960s or early 1970s. Further to this, during the 1970s, a famous series of Bulgari advertisements were produced featuring enameled snake bracelet-watches wrapped around a large B. An example of one of these advertisements appears in Fasel's book and features a black enameled Serpenti watch which is similar in form and detailed design to the present lot. 

According to Fasel, it is believed that fewer than one hundred pieces of snake jewellery were ever produced by Bulgari during the 1960s and 1970s, making the present lot a rare example of the early Bulgari Serpenti collection.

C.f. Fasel, M., Bvlgari Serpenti Collection, Assouline, 2013

Graeme Thompson, the director of jewellery for Bonhams Asia, said, “Without a doubt we are seeing the continued demand for coloured stones, in particular emeralds, sapphires and rubies. Our forthcoming sale has exceptional examples of all these stones and we are expecting interest and bidding from around the globe. ” 

“The appeal of coloured diamonds also remains strong and we are delighted to offer lots including the fancy vivid yellowish orange diamond and diamond earrings. Often referred to as `pumpkin' diamonds, vivid orange and vivid yellowish orange diamonds are exceptionally rare and we believe this may be the first time that a pair of orange diamonds of this type is to be offered at auction.” 

”Signed vintage pieces by the important houses like Van Cleef & Arpels, Cartier, Bulgari, Harry Winston and Marina B continue to capture jewellery lovers and collectors’ interest given they represent the best of what was produced in their respective decade. The craftsmanship which goes into these pieces is phenomenal and buyers are recognising and appreciating this not only in Asia but also worldwide.” 

The auction will preview on 28-30 November at Bonhams Hong Kong Gallery. For further information, please visit https://www.bonhams.com/auctions/22894/. Bids can be placed online on Bonhams website www.bonhams.com, via telephone, in writing, and also in person on the day of the sale. 

Following the sale at Bonhams Hong Kong, Bonhams London will hold its Fine Jewellery sale on Saturday 5 December and at Bonhams New York on 8 December 2015.