Photo: Sotheby's

Every once in a while, the world is reminded of just how much of a miracle of nature the pearl is. In 2016, a Filipino fisherman unveiled a 34kg giant clam pearl he’d kept under his bed for a decade. More recently, in 2019, a 4mm pink oyster pearl, named the Pearl of Abu Dhabi, was unearthed from a Neolithic-age archaeological site dating as far back as 7,500 years.

Yet, despite being a mainstay in jewellery-making since the dawn of civilisation, this organic gem has remained an enigma to many consumers. You might have heard of pearl jewels sold for eye-watering prices, but they also seem ubiquitous and highly accessible in stores.

An untrained eye could find it challenging to differentiate a string of pearls from another, aside from colour and size. Moreover, there are other details like shape, variety, grade, and source to wade through.

Thankfully, the last few years have again seen the spotlight trained on this elegant old-timer. Producers and jewellers began experimenting with modern designs that freed the pearl from the classic strand format; Mikimoto launched gender-fluid lines, and even male celebrities started donning these shimmering orbs. A darling in the latest fashion accessory collections, the gem has been so eagerly adopted by young celebrities that it has become one of the hottest trends today.

Demystifying the pearl

Tiffany & Co. Schlumberger Bird on a Pearl brooch with a near-round natural saltwater white pearl. (Photo: Tiffany & Co.)

The only gemstone made by living creatures, the pearl is formed from concentric layers of calcium carbonate in minute crystalline form. Created spontaneously in molluscs, they were discovered by early humans who scoured the seas for food and came to be coveted by the royal courts throughout antiquity. Such naturally occurring pearls were mainly found in oysters growing in shallow coastal regions.

Only one in 10,000 oysters will produce a natural pearl; of those, one in a million is gem-quality. This rarity makes natural pearls historically expensive and collectable only for the extremely wealthy. In fact, in 1916, Pierre Cartier traded a million-dollar natural pearl necklace (USD$28 million, or $37.2 million, in today’s currency) for a Renaissance-style mansion along New York City’s Fifth Avenue, which has remained the location of the maison’s largest boutique until today. 

As the seas subsequently became depleted of wild oysters, the odds of finding pearls became exceedingly low. The vast majority of natural pearls in today’s market are historic gems owned by old money and sold through dealers or auction houses. However, a tiny but dwindling number of professional free-divers, especially in India and the Persian Gulf, still find the occasional natural pearl.

A model wears the Mikimoto V Code necklace featuring Akoya cultured pearls. (Photo: Mikimoto)

The invention of modern oyster pearl farming in Japan in 1893 saw the rise of the cultured sea pearl, whose quality, accessibility, and affordability stole the thunder from its natural-born cousin. Within the next hundred years, pearl cultivation would spread to the rest of the world as techniques improved to produce better, larger specimens.

In the 1960s, Chinese farmers began to grow freshwater pearls on a large scale in lakes and rivers using the more prolific mussel, which can produce up to 30 or 40 pearls per harvest compared to the oyster’s single gem. Although recent technological advances have resulted in higher-quality, more spherical freshwater pearls, these gems are traditionally irregularly shaped, smaller, less glossy, and durable than their saltwater siblings. As a result, they are not prized and tend to be overlooked by fine jewellers and auctioneers.

In addition to oysters and mussels, other molluscs that create pearls include the lion’s paw scallop, abalone, conch (pronounced “konk”), a sea snail called melo melo, the venus mercenaria clam producing quahog pearls, and the nautilus. This exotic subset of pearls is not cultivated and is mostly harvested by accident in the wild. Of them, conch and melo melo pearls are ultra-rare and highly sought after by jewellers. There is only a one in 15,000 chance of finding a conch pearl, and there is no data on the melo melo.

Know the differences

The formation of a natural pearl begins when an irritant, such as a sand grain or marine parasite, enters a mollusc. As a defence mechanism, its mantle (a thin membrane surrounding the inner organs) starts to secrete layers of a protective substance called nacre to coat the irritant, forming a pearl over time.

While a gem-quality natural oyster pearl takes about two years to form fully, the longer it remains within the shell, the thicker the nacre, the bigger the size, and the higher the quality. Wild gems are almost never perfectly spherical, come in various shapes and colours, and bear blemishes. 

In cultured sea pearls, shell beads are implanted by hand and left to grow for two to four years at least. The most desirable form is round, which accounts for five to 10 per cent of any given harvest, but disruptions to the nacre-layering process often result in shapes such as off-round, drop, oval, button, and baroque (irregular). Controlled growing conditions enable more pearls to achieve perfect symmetry, exquisite shine, and consistent smoothness hardly seen in natural ones.

An Art Deco natural pearl, sapphire, and diamond necklace, circa 1930. (Photo: Bonhams)

A farmed pearl’s colour and size depend on the species of oyster. Pearls from the Akoya oyster grown in Japan and China are white or cream and measure 3 to 11mm. The black-lip oyster grown in French Polynesia produces black, grey, green, purple, and brown Tahitian pearls sized 7 to 18mm. South Sea pearls, which range from 8 to 20mm and come in white, gold, or silver, are cultivated from silver- and gold-lip oysters in Australia, the Philippines, and Indonesia.

Mexico contributes a small production of Cortez pearls sized 8 to 14mm in a wide range of iridescent hues, thanks to the rainbow-lip oyster. Blue is the rarest shade and can originate from any of the varieties above.

By-products of lower value but also used in jewellery-making include blister pearls that grow attached to the inner shell, small keshi or seed pearls that do not have a nucleus, and mother-of-pearl, which is the smooth, luminescent inner shell surface. The mabe pearl is a blister pearl with its bead nucleus removed and filled, then covered with a mother-of-pearl backing.

Presented in 2014, this Cartier transformable necklace and tiara features The Royal Pearl. (Photo: Cartier)

Pearl quality and pricing depend on various factors. The overall colour is determined by a combination of the body colour, overtone (the overlapping translucent colour), and orient (the mix of colours shimmering below the surface). Lustre refers to the intensity of light reflections. The thicker the nacre, the more durable, the better.

Pearls that received dyeing, irradiation (to darken colours), or bleaching have a lower value. Round pearls are the most precious, followed by drop-shaped ones. The surface should be as unblemished as possible. Matching and uniformity are key for pearls in strands or grouped with others in a bejewelled piece.

Despite being a mainstay in jewellery-making since the dawn of civilisation, this organic gem has remained an enigma to many consumers.

Pearls are usually measured in millimetres, but very large cultured pearls may be weighed in carats or grams, where one carat is 0.2g. The size of natural pearls is often calculated in pearl grains, where one grain equals 0.25 carats. One exceptional example is The Royal Pearl which Cartier, having reworked the original setting into a transformable necklace and tiara, presented at the 27th Biennale des Antiquaires in Paris in 2014.

Weighing 166.18 grains (8.3g) and symmetrically drop-shaped with a gorgeous silvery sheen, this gem was first owned by Mary (1867-1953), Queen Consort of the UK and wife of King George V. Patricia Lascelles, wife of the Earl of Harewood, was the last member of the British royal family to own it.

Now is the time

Actress Cate Blanchett wears a Louis Vuitton tourmaline and Tahitian pearl necklace. (Photo: Louis Vuitton)

Despite being an enduring force in jewellery, the pearl has withstood historical highs and lows. Certainly, the past century saw numerous significant gemstone discoveries and innovations that vied for attention. Some might even say the pearl has, time and again, been upstaged by newer, flashier rocks.

Gem experts, however, are glad that the fashion industry and pop culture have once again resurrected the pearl. Will economical freshwater pearls or budget imitation pearls be a bane to the real deal? Absolutely not, they say. Hong Kong-based Jane Ki, deputy director and jewellery specialist at Sotheby’s, points out Gabrielle “Coco” Chanel’s role in igniting a frenzy after launching her first costume jewellery line in the 1920s. It featured oversized faux pearls that elevated the gem’s esteem as a whole. The house is also widely credited for consistently maintaining its appeal through the decades.

John Glajz, a local wholesaler of fancy-coloured diamonds who used to run Australian South Sea pearl business Mondial Jewellers in the 90s, adds, “Just like how diamante costume jewellery helped to sustain the desirability of diamonds, so will such pearls.”

Tweed de Chanel Tweed Pastel bracelet with diamonds and Akoya pearls. (Photo: Chanel)

Beyond trends, real-world events also play into the pearl’s popularity. Simply put, low supply increases demand and hence value. As much as environmental factors such as oyster diseases, pollution, and natural and man-made disasters have wreaked havoc on the pearling industry, the resulting scarcity has seen prices increase — good news for collectors. Ominously for the producers, such events show no signs of respite. Japan has especially borne the brunt: The 1994 red tide, the 1995 earthquake in Kobe, the country’s pearl processing capital, the 2011 tsunami, and a mysterious oyster virus in 2019. 

Stewart Young, Bonhams’ Hong Kong-based director of jewellery, highlights the present rush in China to acquire fine cultured pearls due to fears that Japan’s recent release of treated radioactive Fukushima wastewater would eventually lower pearl production. This is despite scientific data indicating that the water’s radiation levels were negligible, with the move backed by the United Nations. The future is anyone’s guess, as Young and Ki state, but they say the secondary market still carries a strong supply.

Far removed from such problems are natural pearls. Being so niche and increasingly elusive, they still command top dollar. Buoying last year’s pearl craze was also Tiffany & Co’s launch of the Schlumberger Bird on a Pearl capsule collection, made with magnificent natural Persian Gulf pearls from the private estate of connoisseur Hussein Al Fardan.

While natural pearl trade and auctions are more common in Europe and the US, where these gems are traditionally loved, Asians are already warming up to them. Young elaborates, “Asians spent big money on cultured pearls in the 80s and wanted them perfectly round and white. They didn’t like the creamy and slightly yellowish hue of natural pearls.

But after learning more from auctions, the society circle, and the Internet, they changed their minds. The natural pearl earrings Queen Elizabeth II used to wear didn’t perfectly match on both sides and were yellowish.”

This 18th-century Queen Marie Antoinette’s pearl and diamond pendant went under Sotheby’s hammer for USD$36.2 million in 2018. (Photo: Sotheby’s)

Today, natural pearl jewellery could fetch 10 to over 100 times the price of its cultured counterparts. A princess-owned natural pearl double-strand with a diamond clasp sold by Sotheby’s recently exceeded its price estimates by six times, reaching over USD$1.2 million. Legacy jewels have been known to set world records, such as the 18th-century Queen Marie Antoinette’s pearl and diamond pendant that went under Sotheby’s hammer for USD$36.2 million in 2018. These pearls usually come in old settings and designs and are sometimes set with other gems, with provenance boosting their value.

Just like how costume jewellery helped to sustain the desirability of diamonds, so will (freshwater or imitation) pearls.

Fancy-coloured diamond wholesaler John Glajz

As for cultured sea pearls, Glajz says prices have doubled in the past three years. He says the large and rarer South Sea pearl is deemed the most precious, while white is the most popular and versatile colour. Also covetable, say Young and Ki, are gold South Sea pearls, larger Akoyas, black Tahitian pearls with a peacock-green overtone, heritage Mikimoto creations, and designs signed by important jewellers. Once a piece bears a brand name, or if its design is well-appraised by an auction house, its value increases.

The natural and cultured pearls markets are obviously different and have their own demographics, with younger collectors drawn to the latter for their attractive price points. Ultimately, what counts is that buyers cherish sea pearls as treasures of nature that will probably get rarer over time, over pure investment value. After all, as Grace Kelly once said, “The pearl is the queen of gems and the gem of queens.”