here is something infinitely fascinating about pearls. Like precious gems, they are gifts of nature whose existence is the result of a remarkable process. Indeed, scientific studies have disproved the long-held theory that pearls are formed by certain molluscs as a means of defence against a foreign body.

The pearl is a concretion produced by the shell’s mantle in response to injury by a worm or a bite. Each of the mantle’s cells has a protective function; when the mantle is damaged or torn, cells are displaced as part of the healing process and this wonder of nature is formed.

Rare and precious, pearls have existed since the dawn of time. In Merveilleuses Perles, Françoise Cailles writes that the first mollusc shells appeared around five hundred million years ago and that the first traces of pearls were found in Hungary, in Late Triassic rocks, two hundred million years old.

These lustrous spheres have adorned kings and queens, the rich and the famous. But fortunes change and in the 1920s the arrival on the market of large quantities of cultured pearls prompted a dramatic fall in the value of natural pearls.

Again, fortunes change and since the early 2000s, natural pearls are once more highly prized. Their story was the subject of The Pearl Odyssey, an exhibition at the GemGenève fair in November 2023. 

Europa Star Jewellery: What inspired you to curate The Pearl Odyssey?

Ronny Totah: The initial reason was entirely personal: I love pearls! Mathieu Dekeukelaire, director of GemGenève, was also looking into developing an event of some kind about pearls. We put our heads together and came up with The Pearl Odyssey. People have always been fascinated by pearls. The vast majority see them as mysterious and inaccessible. Very few have a real understanding of pearls. They find them as bewildering as a mathematical equation, yet properly explained a veil is lifted. The exhibition was designed as a window into this fascinating world. 

Will it be shown outside Geneva?

Very probably, yes. It won’t be exactly the same as certain pieces loaned by collectors may not be available, but a lot of people would like the exhibition to travel to other countries.

Is it possible to identify a natural pearl with the naked eye?

No. It would have to be identified by a laboratory. But we can ascertain its value.

On the subject of value, natural pearls were treasured by nobility and were worth a fortune until the late 1800s, early 1900s when prices plummeted. Suddenly, nobody wanted pearls. Why was that?

This drop in value coincided with the introduction of cultured pearls by Mikimoto in 1893. With more and more pearls on the market, it became harder to differentiate between a cultured pearl necklace and a natural pearl necklace. Because its outer layer is natural, the only way to identify a cultured pearl is by x-ray, which at that time was a costly and dangerous procedure which wasn’t designed for that purpose. Understandably, customers weren’t willing to pay astronomical sums for pearls when they couldn’t be entirely sure of their origin. They began to buy cultured pearls instead, to the point that some cultured pearls commanded higher prices than natural pearls!

Customers also wanted a necklace of identical pearls, which is impossible with natural pearls. Some have tiny defects and are never the same colour or the same size or perfectly round. All these factors explain why natural pearls fell out of favour until the mid-1990s when there was a spark in interest. Prices started to climb in the early 2000s, reaching a peak in 2016 then levelling off before increasing again.

Brooch set with rubies, natural pearls and diamonds from the jewellery collection of Empress Eugénie, the last Empress of France. Courtesy of Horovitz & Totah.

Why this resurgence of interest?

There has been considerable progress in the methods and techniques for analysing pearls. These methods aren’t new but first there had to be a reversal in trends, given that cultured pearls had dominated the market for more than sixty years. Even now, sellers of cultured pearls would rather there were no distinction between natural and cultured pearls. They want cultured pearls to be referred to simply as “pearls”, as though they were the more “natural” of the two!

Reinstating natural pearls was an uphill battle. Through small gains in the market, once we reached a critical mass, once the price of natural pearls began to increase substantially, the market for cultured pearls registered a significant downturn. It wasn’t unusual, in the late 1990s in New York, for a necklace of cultured pearls to sell at auction for anything between one and one and a half million dollars. Those same neklaces today are worth a fraction of that, no more than a hundred thousand dollars.

Transformable bracelet, Jules Fossin, c.1840. Yellow gold, silver, black enamel, fine pearls, rubies and diamonds. Bracelet can be converted into a pendant. Photo: Pauline Guyon | ©Chaumet Collection

You are a gem and antique jewellery dealer, a pearl specialist and a collector. Did you stop buying when prices bottomed out?

I stopped buying when prices really fell. Pearls weren’t selling and I still had some in stock. Even then, this fall in value in no way diminished my love of pearls. I love their substance. Their mystery, too. Whenever an interesting piece came along, I still bought it.

Is there an exceptional pearl you wish you had kept?

Yes, of course, La Régente. It’s a long story. Back in the day when my father was a partner at Th. Horovitz & Cie, in 1987 we purchased a pearl from Christie’s in New York for around a hundred thousand dollars, with a friend of mine in mind. When the pearl arrived in Geneva, Mr Horovitz told me it could be historically significant. I mentioned La Régente [a pearl the size of a pigeon’s egg, originally acquired by Napoleon I in 1811 and mounted on a tiara gifted by the emperor to his wife, Marie-Louise]. We consulted The Six Voyages of Jean-Baptiste Tavernier Through Turkey into Persia and the East Indies and noticed a pearl that bore a strong resemblance to ours. Tavernier’s book is illustrated with extremely accurate, life-size drawings from various angles. Based on a defect, a slight curve under the pearl which is visible on Tavernier’s illustration and on our pearl, we came to the conclusion that the pearl we had acquired was indeed La Régente. We had a surmount made, similar to the one from the time of the French Crown Jewels, for presentation purposes. The pearl sold as La Régente for about a million. That same year, Bernard Morel [a French jewellery historian] published The French Crown Jewels. A note at the end of the book stated that he had delayed publication after learning that La Régente had reappeared, that he had seen the pearl and concluded that it was not La Régente.

La Régente, sold by Christie’s, 16 November 2005. Price realised: CHF: 3’268’000.- ©DR

What objections did he have?

He cited the weight of the pearl. Already, when we examined it, we had noted a difference in weight. Originally, La Régente weighed 346.27 grains [1 grain equals 0.05 grams] whereas our pearl weighed 302.68 grains. This was almost certainly due to the fact it had been peeled*. In 2005 La Régente came up for auction again at Christie’s. At the viewing I felt terribly embarrassed, as we were behind the name. I went out of my way to avoid the central display case, knowing it would be there, in pride of place. One of Christie’s directors came over, wanting me to see it. I told him I would rather not. I explained that it wasn’t La Régente and that Teddy Horovitz and I had given it that name after studying Tavernier’s drawings, adding that Bernard Morel had disagreed with our analysis. The director asked whether I had read the catalogue. The lot notes for La Régente had been written by Bernard Morel who acknowledged his earlier mistake. He’d based his judgement on the fact that it wasn’t the original mount and on the difference in weight. What a relief! As for the pearl, it went on to sell for CHF 3,268,000.

Princess Zinaida Yusupova wearing La Régente, according to Christie’s, by François Flameng, Oil on canvas, 1894, Hermitage Museum.

A PEARL NECKLACE FOR A MANSION

One story illustrates the value natural pearls could achieve better than any analysis: that of Cartier’s Fifth Avenue flagship store in New York.

In the early 1900s, a beautiful socialite by the name of Maisie Plant - whose husband, Morton F. Plant, was at the head of a vast railroad and steamship empire - fell in love with a necklace of natural South Sea pearls which Cartier had patiently collected, one by one, year after year, and strung as two strands: one of 55 pearls and the other of 73 pearls.

Portrait of Mrs. John E. Rovensky (Maisie Plant), Alphonse Jongers, early 20th century, oil on canvas. Gift of Mrs. Robert Grace. ©Courtesy of The Preservation Society of Newport County

This exceptionally rare jewel was valued at $1 million (around $24 million today): the same as the Plants’ mansion on the corner of Fifth Avenue and 52nd Street. By 1917 many of the wealthy families who had been Morton and Maisie’s neighbours on this particular stretch of Fifth Avenue had moved to new homes north of 59th Street, and businesses and stores were taking over the neighbourhood. Morton Plant wanted a new residence, Maisie Plant wanted the necklace, Pierre Cartier wanted the address. Why not make a deal?

So it was that, on July 21st 1917, an astonishing transaction took place and the necklace was traded for the mansion. The Real Estate Record And Guide reported on the resulting transaction in its July 21, 1917 issue. “The Morton F. Plant dwelling at the southeast corner of Fifth avenue and 52nd street, has been sold to Louis J. Cartier, of Paris, and Pierre C. Cartier, of New York, jewelers, who several months ago leased the property for their business. Ownership was transferred last Saturday for $100 and other valuable considerations.” These other “valuable considerations” being the double strand of pearls.

The deal would prove extremely profitable for Cartier as, a few years later, the value of natural pearls plummeted: a direct consequence of the creation of cultured pearls by Kokichi Mikimoto in 1893. “My dream,” declared Mikimoto, “is to adorn the necks of all women around the world with pearls.” When his cultured pearls began to flood the market in the 1920s, imitating natural pearls almost indistinguishably, the price of natural pearls collapsed.

Following Morton’s death, Maisie Plant married twice more. When she passed away in July 1956, as Mrs Mae Caldwell Manwaring Plant Hayward Rovensky, her estate was sold by the auction house Parke-Bernet. The two strands of pearls fetched $165,000 – a fraction of their original price. As for the Fifth Avenue mansion, it is still Cartier’s New York flagship store.