Pearls for centuries have been known at the “Queen of Gems”. They have such a history that reached far beyond what we today may recognize. Throughout most of recorded history a pearl necklace was comprised of matching spheres it was a treasure with an incomparable value. In fact, for many centuries, it was the most expensive jewelry in the world.
Before today’s cultured pearl, natural pearls were so rare and expensive that they were exclusively for the very rich. At the height of the Roman Empire, when pearl fever was the biggest sign of wealth, the historian Suetonius wrote that the Roman general Vitellis financed an entire military campaign by selling just one of his mother’s pearl earrings.
No one really knows who were the earliest people to collect and wear pearls but I personally tend to agree with George Kunz who published “The Book of the Pearl” he states his belief that an ancient fish-eating tribe, perhaps along the coast of India , initially appreciated the shape and luster of saltwater pearls, which they discovered while opening the oysters for food. No matter the origin, the fever for pearls spread throughout the world.
Pearls have been part of ancient histories. One legend has the Hindu god Krishna discovering pearls when he plucks the first one from the sea and presents it to his daughter on her wedding day. In China, Shu King, a 23rd Century B.C. scribe sent as a tribute to a lesser king, “strings of pearls not quite round”. In Egypt, decorative mother-of-pearl was used at least as far back as 4200 B.C. but the use of pearls themselves seem to have been later, perhaps related to the Persian conquest in the 5th century B.C. Rome’s pearl craze reached great heights during the first century B. C. when Roman women upholstered couches with pearls and sewed so many into their gowns that they actually walked on their pearl encrusted hems.
During the Long History of pearls, the principal oyster beds lay in the Persian Gulf, along the coasts of India and the Red Sea. Chinese pearls came mainly from freshwater rivers and ponds, whereas Japanese pearls were found near the coast in salt water. That being said, nearly all the pearls in commerce at that time originated from those few areas.
North and South America’s history with pearls. As all of Europe raced to capitalize on what Columbus had stumbled upon, the English colonizers along North America’s Atlantic coast and the French colonizers to the north and west , all found the aboriginal peoples wearing pearls. They then discovered freshwater pearls in many great lakes all through the new world. So many pearls were exported to Europe that the New World quickly gained the nickname “Land of Pearls” . While South America set a new standard for large white and black saltwater pearls, slaves of the Spanish settlers were forced to dive for these oysters so the pearls could be sent back to Spain for the Royalty and Aristocracy.
Sadly, “the Land of Pearls” would not last by the late 1800’s as overfishing in the Americas depleted the beds..
A New Pearl Culture is Born
Kokichi Mikimoto, the son of a noodle maker, had a great dream and a very hard working wife, Ume. Together they set about to do what no one else had done. To entice oysters to produce pearls on demand. What he didn’t know was that government biologist Tokichi Nishikawa and carpenter Tatsuhei Mise had each independently discovered the secret of pearl culturing. Inserting a piece of oyster epithelial membrane (that’s the lip of the mantle tissue) with nucleus of shell into an oyster’s body or mantle which causes the tissue to form a pearl sac. That sac then secretes nacre to coat the nucleus, thus creating a pearl.
Mise received a 1907 patent for his grafting needle. When Nishikawa applied for a patent for nucleating, he realized that he and Mise had discovered the same thing. In a compromise, the pair signed an agreement uniting their common discovery as the Mise-Nishikawa method, which remains today the heart of pearl culturing. Mikimoto had received an 1896 patent for producing hemispherical pearls , or mabes, and a 1908 patent for culturing in mantle tissue. He could not use the Mise-Nishikawa method without invalidating his own patents, so he altered the patent application to cover a technique to make “Round”, “Oval” etc. pearls in the mantle tissue, which was granted in 1916. With this technicality, Mikimoto began an unprecedented expansion, buying the rights to the Mise-Niskikawa method and eclipsing those originators of cultured pearls, leaving their names only for history books. Largely, by trial and error over a number of years, Mikimoto discovered that he had the highest success rates when he inserted a round nuclei cut from mussel shells. Although some countries continue to test other nuclei, mussel shells have been the basis for virtually all cultured pearls for over 90 years.
Even though third with his patents and his secrets, Mikimoto revolutionized pearling and made pearls available to virtually everyone in the world
A Pearl is Born
The birth of a pearl is truly a miraculous event! Unlike other precious items such as gemstones or metals which must be mined and extracted from the earth, pearls are grown by live oysters or mussels. Gemstones must be cut and polished to bring out their beauty, pearls need no treatment to reveal their glory. They are born from the oysters complete, with a shimmering original perfection, a lustre and soft inner glow unlike any other gem in the world.
A pearl begins its life as a foreign object, such as a parasite or piece of shell that accidentally lodges itself in an oyster’s soft inner body where it cannot be expelled. In cultivated oysters, the object is placed in the body. To ease this irritant, the oyster’s body takes defensive action against the irritant. The oyster begins to secrete a smooth, hard crystalline substance around the irritant in order to protect itself. This substance is called “nacre”. As long as the irritant remains within it’s body, the oyster will continue to secrete nacre around it, layer after layer. Over time the irritant will be completely encased by the silky crystalline coating. The nacre is composed of microscopic crystals of calcium carbonate, aligned perfectly with one another so that light passing along the axis of one crystal is reflected by another to produce a rainbow of light and colour. The result, ultimately, is a lovely and lustrous gem called a pearl.
Cultured pearls share the same properties as natural pearls. Oysters form cultured pearls in an identical fashion. The only difference is a person carefully implants the irritant in the oyster, rather than leaving it to chance and nature. After implant of the irritant, humans step aside and let nature create this beautiful miracle. This process is referred to as “nucleation” and also called grafting or seeding. Highly skilled technicians carefully open live pearl oysters and with surgical precision make an incision in the oyster’s body. They then place a tiny piece of mantle tissue from another oyster into a relatively safe location in the oyster, then they place a small round piece of shell, or nucleus beside the inserted mantle tissue. The nucleus is a mother of pearl bead made from a mussel. The cells from the mantle tissue develop around the nucleus forming a sac which closes and starts to secrete nacre, the crystalline substance that forms the pearl. The nucleated oysters are then returned to the sea (for salt water pearls) or to the lake or river (for fresh water pearls) where in sheltered bays rich in nutrients they feed and grow, depositing layer after layer of lustrous nacre around the nuclei implanted in them. The oysters are given the utmost care during this time, while suspended in the water, from rafts above. Technicians check water temperatures and feeding conditions daily at various depths, moving the oysters up or down as appropriate. At times the oysters are lifted from the sea or lake for cleaning and health treatments. Seaweed, barnacles and other sea or water organisms that might interfere with their feeding are removed from the oyster’s shells. The shells are also treated with medicinal compounds to discourage parasites. Over time, after many months of growth and care, the oysters are ready for harvest. Those who have survived are brought ashore and opened and when everything has gone well, a beautiful and very valuable cultured pearl is inside.
Akoya and Tahitian Pearls
Cultured Akoya Pearls
Generally, Akoya pearls take 10-18 months from the time they are nucleated to the point that they’re ready for harvest. Akoya pearl harvesting are the most difficult and costly to grow because of the low survival rates of the host oysters. These South Sea pearls are considered the “Rolls Royce” of cultured pearls. They are among the rarest and most costly cultured pearls. They are cultivated in the waters off Australia, Indonesia, the Philippines, Japan and Thailand.
These pearls form in the White lipped oyster Pinctada maxima one of the smallest oysters. Because of their long cultivation period, these pearls develop an exceptionally thick coating of nacre, perhaps the thickest of all cultured pearl varieties. They are more valuable than freshwater pearls because of their lustre, quality and rarity.
In Tahiti, the story is told of the god Oro, who long ago used his rainbows to visit earth, giving the mother of pearl its iridescence and Tahitian pearls their entrancing dark colour. Tahitian pearls are not just black as they’re commonly called, but they themselves are rainbows of colour that gives that black look that make them so prized today. Today Tahitian Pearls are not cultivated in Tahiti, but in the areas around French Polynesia in the middle of the South Pacific Ocean.
Tahitian Pearls form in the Black lipped oyster Pinctada margaritifera , which is almost twice the size of the Japanese Akoya oyster.
Fresh Water Pearls
As the name suggests, fresh water pearls are harvested in fresh water. Fresh water pearls are the most cultivated pearls in the world. The Hybrid pearl mussel Hyriopsis Cumingi is the most commonly used to seed the pearl. The seed cultivates in 6-12 months, much more quickly, compared to the use of other oysters or mussels. The fresh water pearl has a medium coating of nacre The majority of the world’s fresh water pearls come from the region of Shanghai China.
Fresh Water Pearls/Monster/Keshi
Fresh Water Cultured Baroque Pearls
These are found in the large mussels. They are seeded with may seeds and produce anywhere from 4-40 baroque pearls in all shapes and sizes. They have been given the name of monster oyster in the industry, their actual name is Hyriopsis Cumingii and the colours of the pearls vary from white to cream to pink and lavender but some have been found with purple and black tones.
Although they often occur by chance, they are not considered natural. They are a by-product of the culturing process, and hence do not happen without human intervention. They are quite small, typically only a few millimeters. Keshi pearls are produced by many different types of salt and fresh water mussels. Keshi pearls are actually a mistake in the cultured pearl seeding process. In the seeding process, if the piece of mantle should slip, a pearl forms in the baroque shape.