Pearls have always been highly desirable. This undeniable enchantment has many causes and it is in part associated with the extreme rarity of high quality specimens. These solid concretions as seen in jewellery are typically composed of nacre that is formed by layers of bio-mineralized calcium carbonate in the form of aragonite and/or calcite , organic matter (e.g. conchiolin) and intersticial water. Their formation being the result of the activity of certain molluscs, specially the popularly called "pearl oysters" (species of the genus Pteria and Pinctada) and also of freshwater mussels namely the European pearl mussel, Margaritifera margaritifera). Good quality natural pearls are, indeed, rare and their desirability has much to do with their peculiar visual characteristics as their unique lustre and near surface sheen effect or overtone (iridescence) sometimes called "orient" in the trade.
The high esteem for pearls is well expressed in many sacred texts, from the Hindu Rigveda to the Tanak, Bible and the Koran, where there are interesting allusions to pearls as symbols of purity and value. There are also numerous representations of pearls in portraits of sovereigns and powerful men and women, expressing great wealth. The dichotomy between purity and chastity versus ostentation and power is therefore culturally well cemented and it was superbly explored by Johannes Vermeer (1632-1675), namely in his famous painting "Girl with a Pearl Earring" in ca. 1665.
For millennia, natural pearls were fished in many parts of the world from wild mollusks, specially saltwater and freshwater bivalves. The most popular were found specially in certain marine species, like the small-sized Gulf pearl oyster (Pinctada radiata) in the Persian and Mannar Gulfs or the large white-lipped or silver-lipped pearl oyster (Pinctada maxima) in southeast Asian to Australian waters. Divers in these regions collected the living shells for food, fish bait, mother-of-pearl if appropriate or to seek the occasional pearls that only very rarely had good size and gem quality suitable for jewellery. The over exploitation of several resources led to a decrease in availability that contrasted with a huge increase in demand in the 19th century, which caused the overall perception that good quality pearls were really very expensive, almost impossible to obtain. The famous case of the Mae Plant superb necklace, traded by $100 and a mansion in Manhattan, is one of the most striking examples of pearl values on those times (read more on this case in the article "A New York Mansion Worth of Pearls" (here on this blog).
The first attempts
It is in this historical and market context that the first attempts to grow pearls as a cultured product take place. It must be said, however, that in the 13th century attempts were made in freshwater mussels in China and cultured blisters were reported with the shape of Buddha. Similarly, in the 18th century the famous Swedish scientist Karl Gustav von Linne (1708-1778), better known as Linnaeus, managed to grow a drilled cultured pearl inside a pearl mussel. It was, however, in the late 1800's that the real developments started to take place, this time in Japan. Three gentlemen in particular contributed greatly to these discoveries that changed the paradigm of pearl consumption: a marine biologist, Tokichi Nishikawa (1874-1909), a carpenter, Tatsuhei Mise (1880-1924) and the son of a noodle merchant from Toba, Kichimatsu (Kokichi) Mikimoto (1858-1954).
Mikimoto started his experiments in 1888 using the local akoya pearl oyster in Benten-shima and 5 years later, in 1893, with the help Prof. Kakishi Mitsukuri of Tokyo University, already managed to produce hemispherical "pearls" that, technically, are cultured blisters, not pearls (since they did not grew in pearl sacs). The akoya pearl oyster, or akoya-gai, is a Japanese species from the so-called akoya complex, being usually referred to as Pinctada fucata or Pinctada fucata martensii. The process involved the use of sheel bead or nuclei obtained from freshwater mussels from America inserted between the host shell and it's nacre-secreting mantle. After applying for a patent, Mikimoto finally received it in 1896, being the first patent for culturing pearls. Soon after, huge quantities of Mikimoto cultured blisters were being marketed as "culture pearls".
The refinement of the culturing process
In spite of the success, Mikimoto was not totally satisfied since he was looking for a method to grow a whole cultured pearl, also known as a cyst pearl, not blisters. In 1902, Tatsuhei Mise managed to seed a few thousands of local akoya oysters using plumb and silver beads as nucleus, and after two years they obtained round cultured pearls. The process was patented in 1907, being the first patent on a growth process for round cultured pearls. At the same time, Tokishi Nishikawa was using gold and silver sphere nucleus. This method became known as Mise-Nishikawa method where a tiny piece of mantle tissue (a graft) from another akoya oyster was placed next to the spherical bead inserted in the mollusc's gonads. Some authors do atribute the method to William Saville-Kent, a British born Australian and not to the Japanese team.
Mikimoto insists in the use of Mississipi basin freshwater mussel's shell as beads and uses a considerably large tissue graft covering the whole bead and in 1905 he got his first whole cultured pearl and eventually patented the process in 1908. Officially, 1905 is the year when the first whole cultured cyst pearl was successfully produced inside a pearl oyster. His main discovery happened only when he associated the grafting method of Mise-Nishikawa, using small pieces of tissue, with freshwater shell beads inserted in the gonads. By 1916, Mikimoto had already began producing significant quantities of akoya beaded cultured pearls and made history in the development of the culturing method still is use today in the production of most saltwater cultured pearls, including in the South Seas (Pinctada maxima) and Tahiti (Pinctada margaritifera), just to name the most abundant. In the 1920's a series of advances and drawbacks happened in marketing and distributing the new akoya cultured pearls namely in Paris, the European capital for natural pearl trade, where Mikimoto faced a difficult court case. The international jewellery community eventually recognised the term "cultured pearl" and everything was concurring to the growing popularity of the new product that was competing with their natural and rare counterparts: the then very expensive natural pearls.
Impact on the market
The efficient pearl farming methods of Mikimoto and his ingenious marketing skills offered beautifully looking cultured pearls at a fraction of the price of almost similar-looking natural pearls. The fact that there was a round bead inside contributed to a more regular round external shape of cultured pearls, a characteristic only rarely seen on natural pearls, specially in uniform strands. The quantities produced (over 10 million cultured pearls by late 1930's) also made impact in the way pearls could and would be used in jewellery, affecting designers and consumer behaviour or taste.
Mikimoto's vision was beyond producing cultured pearls and, as already mentioned, he also was keen in marketing them and setting them in jewellery, in a vertically integrated business model. His famous words to the emperor of Japan summarise his dream of "adorning the necks of all woman in the world with pearls". In 1899 he founded the first Mikimoto Pearl Shop in Tokyo, a small firm that eventually became the international group now known as Mikimoto Pearl Island, with its headquarters in Toba. In 1907 Mikimoto Gold Work Factory (today known as Mikimoto Jewelry Mfg. Co. Ltd.) was created and international branches started to open, the first inaugurated in London in 1913. His vision and entrepreneurship were recognised by Hirohito, Emperor of Japan, that invited him for a dinner in 1930 and eventually granted him the honourable title of official jeweller to the Imperial House of Japan. In a few decades after his first experiments, similar ventures would begin in other parts of the world and, today, the many pearl farms in places like Australia, French Polynesia, Indonesia, The Philippines, Fiji, Vietname and Mexico, just to name the most important locations, are testimonies of Mikimoto's legacy to the world of pearls.
The impact of Kokichi Mikimoto's activities was very significant in many aspects, beyond the obvious changes in the paradigm of pearl trading and use in jewellery. Today, it is perfectly accepted that cultured pearls are a normal, sometimes, extraordinary, gem product and that natural pearls became a niche product, specially in certain geographies and in the antique's markets. Being truth that high quality natural pearls still command very high prices, the bulk of the market by volume and by value is today lead by cultured pearls, specially the freshwater cultured pearls in terms of volume.
The obvious need to separate natural from cultured pearls, especially in the high-end segments was present from the very beginnings of this story in the first quarter of the 20th century, when value perception for pearls was indeed very high. If flame fusion (Verneuil) synthetic rubies were behind the establishment of the first gemmological education projects, cultured pearls were, in turn, the most important cause for the foundation in 1925 of the first gemmological laboratory in the world at the London Chamber of Commerce and in 1929 of the Laboratoire Francais de Gemmologie that is still active today, being the oldest gemmological laboratory in the world. The famous British gemmologist Basil Anderson (1901-1984) was the director London laboratory that was specifically set-up with the best instrumentation available at the time to face the then modern challenges and contribute to the consumer's confidence in the jewellery industry. Even today, highly sophisticated laboratories rely on the latest technology and science to perform this very task (e.g. DANAT, SSEF, GIA Thailand).
A tribute is, therefore, in order in honouring this entrepreneur that left a distinguished legacy in the way pearls are used today allover the world and that was a key figure in the advancement of gemmology and gemological laboratories as a necessary tool to supporting the jewellery industry and promoting consumer confidence.
Unless otherwise stated, all photos are cortesy of Mikimoto