All About Pearls

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Podcast Transcript

Centuries ago, the most expensive jewelry in the world wasn’t made of diamonds, rubies, or emeralds. 

Rather, they were made with an extremely rare substance that was occasionally found inside of clams and oysters: pearls.

Pearls were so valuable that they could only be possessed by kings, queens, and emperors. 

Today, the manner in which pearls are made is pretty much the same, but they are more common than at any point in history. 

Learn more about pearls, how they are made, and how they have been harvested throughout history on this episode of Everything Everywhere Daily.

Some of the most valuable substances in the world are gemstones.

Gemstones are pieces of minerals that form a crystal lattice at the atomic level. Diamonds, rubies, sapphires, and emeralds are examples of such crystalline minerals. 

However, there are some gemstones that are not crystals at all but are still considered to be very valuable. Opals are an example of something considered a gemstone but do not have a crystalline structure. 

Amber is often classified as a precious gem, but it is really just fossilized tree sap. 

However, there is one substance that is neither a crystal nor a fossil, and it is continuously produced by organic means in many parts of the world: pearls. 

Pearls are unlike any other gemstone in that they are harvested from a living organism, not mined from the Earth.

So, what exactly is a pearl, and what makes pearls so different?

Pearls come from mollusks, primarily two different types of bivalves: the saltwater pearl oyster and the freshwater pearl clam. However, it is possible for a pearl, or a pearl-like object, to appear in any type of mollusk with a shell. 

Pearls are created when an irritant, usually a piece of shell or a grain of sand, gets trapped in the fleshy inside of a bivalve. In an effort to protect itself, the mollusk will coat the irritant with a substance called nacre. 

Chemically, nacre is just CaCO3 or calcium carbonate, the same stuff that makes up the mineral calcite, limestone, and hard coral. However, nacre has a different physical structure. Under an electron microscope, nacre has a series of very thin stacked plates. 

Nacre is also the exact same substance that lines the inside of a shell, and in this form, it is called mother-of-pearl. 

When an irritant is covered in nacre, the mollusk will keep secreting layers, causing the covered irritant to grow and eventually become a pearl. 

That is really all there is to it. 

Despite how simple the process sounds, naturally occurring pearls are actually quite rare. 

The odds of a pearl being produced are only about one in ten thousand. However, even if there is a pearl, the odds are it won’t be a very good pearl. When you see a pearl in jewelry, you probably see a pearl that is almost perfectly spherical without any blemishes. 

Just as with mineral gemstones, there are ways of evaluating and grading pearls. The two primary attributes are shape and luster. 

Most natural pearls are not spherical but rather have an irregular shape. These irregular pearls are known as baroque pearls. Some baroque pearls can still have symmetry and might be in the shape of a teardrop, and those can still have quite a bit of value.

The luster of a pearl, including its color, has to do with several factors, including the type of mollusk that produced it, the condition of the water, including salinity and temperature, impurities in the water, and the thickness of the layers of nacre that are produced.

There are some pearls known as non-nacreous pearls which have little to no luster, but they are still made out of calcium carbonate.

Because there are so many variables, even though the odds of a mollusk naturally making a pearl is one in ten thousand, the odds of getting a gemstone-quality pearl is about one in a million. 

This is why pearls in the ancient world were considered so rare and valuable. Something like a string of pearls in a necklace was so rare that almost no one outside of a king or emperor could hope to possess it.

So, finding a gem-quality pearl prior to the 20th century was the equivalent of winning the lottery.

One of the earliest references to pearl harvesting come from Mah?va?sa, which was a record of ancient Sri Lanka. It claims that the best pearl-harvesting region was in the Gulf of Mannar, between Sri Lanka and India.

There were also notes of productive pearl harvesting in the Persian Gulf and the Red Sea. The Roman author Pliny the Elder noted that the Persian Gulf produced the finest pearls. 

China also had a productive pearl-growing area in the South China Sea, and remember that productivity is really relative when it comes to pearls. 

When the Spanish came to the new world, they found productive pearling off the coast of Venezuela near the island of Margarita.

Because of their rarity and value, pearls have received special mention throughout history.

In the Mah?va?sa, which I previously mentioned, Prince Vijaya, the first recorded King of Sri Lanka, was noted as bringing pearls to visit the king of the Pandyan dynasty in Southern India. 

Julius Caesar had an obsession with pearls. One of the reasons he supposedly invaded Britain was because of their freshwater pearls. Likewise, as dictator, he banned the wearing of pearls by anyone other than the highest classes in Roman society. 

There was a story told by Pliny the Elder about a bet that Cleopatra made with Marc Antony. Antony had a reputation for throwing extravagant banquets, and Cleopatra bet Antony that she could host a banquet that would cost 10,000,000 sesterces, or about $30 million dollars today. 

Antony didn’t believe that such a thing was possible, so he made the bet. 

Cleopatra supposedly won the bet by dissolving her most valuable pearl in vinegar and drinking it. 

Here, I should note that the story is almost certainly apocryphal. It is true that vinegar, which is an acid, can dissolve a pearl, which is nothing but calcium carbonate. However, there are several YouTube videos where people have taken pearls and tried to dissolve them in vinegar to test the Cleopatra story. 

The answer is that it would take a long time for a pearl to dissolve-long enough that you couldn’t dramatically win a bet by dropping a pearl in vinegar and then drinking it.

One of the most famous pearls in history is the Peregrina Pearl. In 1513, a large and beautiful teardrop-shaped pearl was found off the coast of Panama. The pearl was given to the governor of Panama, Don Pedro de Temez, who, in turn, gave the pearl to King Philip II of Spain.

Philip made the pearl part of the Spanish crown Jewels, and it remained in the hands of Spanish monarchs for the next 200 years. It was dubbed La Peregrina, meaning “the female wanderer.”

It remained in the hands of the Spanish Kings until Napoleon installed his brother Joseph Bonaparte as king in 1808. He was disposed of after five years, and when he fled Spain, he took La Peregrina with him.

He left the pearl to his nephew, who became Napoleon III of France. When he was exiled to England, he sold it to James Hamilton, Duke of Abercorn.

The pearl remained in the Hamilton family until 1969 when it was sold at auction. It was purchased for $37,000 by the actor Richard Burton, who bought it for his wife Elizabeth Taylor. 

It was sold again in 2011, after Elizabeth Taylor’s death, for $11 million dollars, to a private collector.

One of the greatest pearls ever recorded was the Pearl of Lao Tzu. It was purchased from a fisherman in the Philippines in 1939 by an American archeologist named Wilburn Dowell Cobb.

The pearl is a giant, non-nacreous pearl that came from a giant clam. It measures 24 centimeters or 9.45 inches in diameter and weighs 6.4 kilograms or 14.2 pounds.

The pearl was appraised by gemologists in 2007 at $90,000,000.

However, the Pearl of Lao Tzu pales in comparison to the Giga Pearl. Also discovered in the Philippines, the pearl is 27.65 kilograms or 60 pounds 15 ounces. It has been appraised for as much as $200 million dollars. 

While there have been some very expensive pearls in history, you might be thinking that pearls aren’t nearly as rare as I’ve made them out to be. After all, maybe you or someone close to you owns some pearls. 

That is because, up until this point, I’ve only been talking about natural pearls, which are quite rare. Almost all the pearls which are sold today are cultivated pearls. 

Instead of hoping you might find a pearl by chance, with cultivated pearls, you are helping the process by growing oysters and adding an irritant to ensure that a pearl grows. 

The process of cultivating pearls is credited to the Japanese entrepreneur Kokichi Mikimoto. 

Mikimoto didn’t actually develop the technique of cultivating pearls. That was done by the British Biologist William Saville-Kent in Australia. However, Mikimoto did take the technique and developed his first oyster farm in 1888. 

It took years of trial and error, but eventually, Mikimoto was able to create consistently spherical pearls, which were indistinguishable from natural ones. 

He developed a series of innovations that allowed a pearl grower to inject an irritant in the shell. 

In addition to growing cultured pearls, he opened up his own store in the high-end Ginza district of Tokyo to develop a complete vertical integration. 

Today, the Mikimoto company is still the world’s largest company dedicated to pearls. 

However, Mikimoto no longer has a monopoly on cultured pearls. Pearls are grown in many places around the world. 

Today, the largest producer of pearls is China, followed by Japan. 

Pearl-growing industries have been developed in many tropical countries, including many small islands in the Pacific. 

One of the biggest growers is French Polynesia, where pearls are the biggest export. They, along with other Pacific islands, have developed a specialization in growing black pearls. 

Black pearls are highly sought after and command a premium, although they aren’t really black so much as a lustrous grey.

I should close on one interesting note. As I mentioned, natural pearls are rare. However, every so often, someone orders oysters in a restaurant and finds a pearl in their oyster. It is a rare enough event that it usually makes local newspapers. 

An average restaurant pearl will usually sell for about $200-400, which will more than cover the price of your meal. 

Today, thanks to cultivation and the innovations by Kokichi Mikimoto, pearls are much more common than they were in the past. Pearls have become cheap enough that they could be purchased by regular people, not just kings and emperors. 

No matter how common pearls have become, they still have a compelling beauty and are part of a legacy that dates back centuries.