The Aga Khan Emerald: ‘We might see an emerald of this quality come up for sale once every five or six years. It’s one of the rarest treasures on Earth’

This storied gem was part of a brooch commissioned from Cartier in 1960 by Prince Aga Khan for his bride, Nina Dyer. In 1969, François Curiel witnessed its sale at Christie’s to Van Cleef & Arpels, and describes its reappearance at the auction house today, 55 years later, as ‘a very exciting moment’

The Aga Khan Emerald. A Cartier emerald and diamond brooch, 1960. Square-shaped emerald of 37.00 carats, marquise-shaped diamonds, platinum and 18k yellow gold. 4.9 cm high. Sold for CHF 7,765,000 (US$8,859,865) on 12 November 2024 at Christie’s in Geneva

On 1 May 1969, Christie’s held its inaugural Magnificent Jewels sale at Le Richemond Hotel in Geneva. ‘Christie’s Geneva had opened its doors just six months before the sale,’ says Max Fawcett, head of Jewellery at Christie’s in Geneva. At that time, the Swiss banks were booming and few tariffs were applied to the sale of jewellery, making Switzerland a hotspot for luxury brands and jewellery sales. ‘Christie’s looked at opening offices in Zurich and Basel, but Geneva made the most sense as a centre of luxury.’

The sale, which comprised 108 lots, drew important collectors from across Europe, as well as representatives from high jewellery brands including Boucheron, Bulgari, Cartier, Chaumet and Harry Winston.

The catalogue for the inaugural Magnificent Jewels sale held by Christie’s in Geneva on 1 May 1969, headlining the property of the late Nina Dyer

The sale cataloguing described the ‘magnificent emerald and diamond clip brooch, composed of a superb square-cut emerald in a border of twenty navette-cut diamonds forming a fancy lozenge-shaped cluster, by Cartier, Paris — approximate weight of emerald 37.41 carats, and approximate total weight of diamonds 12.04 carats’

‘I was 21 years old and fresh out of gemmological school,’ recalls François Curiel, chairman of Christie’s EMEA, who accompanied his father to both the dealer preview and the inaugural Magnificent Jewels evening auction. ‘It was a very chic event: all the ladies were beautifully dressed, and all the men wore dark suits.’

According to Curiel, many of the clients in attendance had travelled to Geneva in the hope of acquiring one of the 45 jewels offered for sale from the collection of Nina Dyer.

The inaugural Magnificent Jewels sale in Geneva, 1969, with then Christie's Chairman Peter Chance at the rostrum. The auction achieved a total of CHF 12.7 million, with the emerald and diamond clip brooch selling to Van Cleef and Arpels for CHF 900,000

The inaugural Magnificent Jewels sale in Geneva, 1969, with then Christie’s Chairman Peter Chance at the rostrum. The auction achieved a total of CHF 12.7 million, with the emerald and diamond clip brooch selling to Van Cleef & Arpels for CHF 900,000. Photo: Pfändler / RDB / ullstein bild via Getty Images

Born in Ceylon (now Sri Lanka) in 1930, Dyer moved to England to pursue a career in fashion. By the age of 20, she had found success as a model in Paris, working for the likes of Balmain. In June 1954, she married Baron Hans Heinrich Thyssen-Bornemisza, heir to the Thyssen industrial empire.

The couple divorced in 1956, and within a year Dyer had met Prince Aga Khan, the second son of Sultan Mahomed Shah Aga Khan III, the hereditary Imam of the Ismaili sect of Shi’ism.

Prince Aga Khan and Nina Dyer photographed in Antibes on the French Riviera, May 1957, before their marriage in August of that year

Prince Aga Khan and Nina Dyer photographed in Antibes on the French Riviera, May 1957, before their marriage in August of that year. Photo: René Vital / Paris Match via Getty Images

Dyer and the prince married in 1957, and Dyer took the name Princess Nina Aga Khan. Over the course of their marriage, the prince lavished her with splendid gifts, including luxury sports cars and precious jewels by celebrated makers such as Cartier, Mappin & Webb and Harry Winston.

‘Nina Dyer’s jewellery collection epitomised elegance, refinement and good taste,’ recalls Curiel, adding that each piece offered for sale was of exceptionally high quality. ‘The atmosphere in the saleroom was electric. Bids came from all over the room, and some lots took more than five minutes to sell because of the great number of people bidding for them.’

Among the top lots offered was an emerald and diamond brooch commissioned by Prince Aga Khan from Cartier Paris in 1960. The centrepiece, a 37-carat square emerald, was bordered by 20 marquise-shaped diamonds with an approximate total weight of 12.04 carats.

Open link https://www.christies.com/en/lot/lot-6507459
The Aga Khan Emerald. A Cartier emerald and diamond brooch, 1960, sold for CHF 7,765,000 (US$8,859,865) on 12 November 2024 at Christie's in Geneva

The Aga Khan Emerald. A Cartier emerald and diamond brooch, 1960. Square-shaped emerald of 37.00 carats, marquise-shaped diamonds, platinum and 18k yellow gold. 4.9 cm high. Sold for CHF 7,765,000 (US$8,859,865) on 12 November 2024 at Christie’s in Geneva

Open link https://www.christies.com/en/lot/lot-6507459
The Aga Khan Emerald. A Cartier emerald and diamond brooch, 1960, sold for CHF 7,765,000 (US$8,859,865) on 12 November 2024 at Christie's in Geneva

In 1969, the Cartier-designed brooch sold to Van Cleef & Arpels and was later acquired by Harry Winston, who turned it into a pendant. ‘The fact that it has passed through the hands of three of the greatest jewellers in the world attests to its exceptional quality’

The combination of the huge size, even green colour and high degree of transparency made it exceptionally rare. ‘The fact that it’s set in an original piece by Cartier is the cherry on the top,’ says Fawcett.

On 12 November 2024, the Aga Khan Emerald will be offered in the Magnificent Jewels sale at Christie’s in Geneva for the second time in just over 55 years. ‘It is a very exciting moment,’ says Curiel, who joined the auction house’s jewellery department as an intern shortly after the inaugural sale. ‘I am still here today and am thrilled to be able to handle the famous 37-carat Aga Khan Emerald before it is sold at Christie’s once again.’

‘Muzo emeralds have long been considered the most beautiful and valuable in the world, thanks to their intense green colour and high degree of transparency’
Specialist Max Fawcett

The gem was unearthed in Muzo, a Colombian emerald mine about 60 miles north of what is now Bogotá. In use for at least five centuries before the Spanish arrived in the New World, Muzo has provided some of the most famous stones in history, including the Devonshire — an uncut stone weighing an enormous 1,383.95 carats, named after the 6th Duke of Devonshire, who acquired it from Emperor Dom Pedro I of Brazil around 1831.

‘Emeralds have been treasured since antiquity,’ says Fawcett, adding that Cleopatra had her own mines in Egypt. ‘Since the colonial era, however, Muzo emeralds have been considered the most beautiful and valuable in the world, thanks to their intense green colour and high degree of transparency.’

One remarkable feature of the Aga Khan Emerald is its unusual shape: ‘It’s extremely thin and flat, and so it looks like a 50-carat stone. Flat stones, however, tend to lose their colour at the centre, but this one is a completely even green’

Although it is natural for emeralds to feature inclusions and surface-breaking fissures, this emerald is particularly clean and crisp, and, most importantly, has not been treated in any way. ‘Surface fractures are often filled with oils and polymers to improve the clarity and sometimes the stability of an emerald,’ explains Fawcett. ‘To find a stone of this size with no indications of clarity enhancement is extraordinary.’

Another remarkable feature is its unusual shape. ‘It’s extremely thin and flat, and so it looks like a 50-carat stone,’ says Fawcett. ‘Flat stones, however, tend to lose their colour at the centre, but this one is a completely even green.’

In 1969, the Aga Khan brooch sold to Van Cleef & Arpels for CHF 900,000. It was among the top lots of the sale, which achieved a total of CHF 12.7 million. The brooch was later acquired by Harry Winston, who turned it into a pendant. ‘The fact that it has passed through the hands of three of the greatest jewellers in the world attests to its exceptional quality,’ says the specialist.

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Fawcett expects the gem to attract great interest from private collectors around the world when it returns to Christie’s in Geneva. ‘Emeralds are hot right now, and this one ticks all the boxes,’ he says. The fact that it is fresh to market only increases its desirability. ‘We might see an emerald of this quality come up for sale once every five or six years,’ he adds. ‘It’s an exciting opportunity for jewellery collectors to acquire one of the rarest treasures on Earth.’

Featuring a curated selection of historical and modern jewellery from houses such as as Harry Winston, Cartier and Van Cleef & Arpels, Christie’s Magnificent Jewels auction will take place at the Four Seasons Hotel des Bergues in Geneva on 12 November 2024, with pre-sale viewing 8-12 November

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