Akoya Pearls
It was in Japan that the first successful cultivation of pearls was achieved in the early 1900s with Akoya oysters. From that time on, the cultivation techniques of Akoya pearls significantly increased pearl productivity and made pearl jewelry affordable. Great luster and perfect roundness are the hallmarks of Akoya pearls, which are the most representative of the classic elegant style. After decades of development, the Japanese Akoya cultivation technique has been widely adopted and developed by other counties, such as China, South Korea, Vietnam and Australia.
History
The perilculture process of Akoya pearls was first developed by the British Biologist William Saville-Kent in Australia about 100 years ago, and later brought to Japan by Tokichi Nishikawa and Tatsuhei Mise. Kokichi Mikimoto bought their patent and further developed the techniques experimentally and practically. The technology was commercially applied to Akoya pearl oysters in Japan in 1916. Mise's brother was the first to produce a commercial crop of pearls in the Akoya oyster.
Japanese Akoya pearls are the first successfully cultivated pearls using the nucleus implantation technique, and this technique is now widely used to cultivate saltwater pearls all over the world.
Akoya pearl production today
Akoya pearls produced in Japan are hosted by a species of small pearl oyster, Pinctada fucata martensii, the pearls of which are normally no bigger than 6 to 8 cm and thus, smaller than most other pearl types. Akoya pearls larger than 10mm in diameter are extremely rare and of great value. The colder water conditions in Japan allow for a slower growing of Akoya oyster and the formation of more lustrous nacre.
China started the cultivation of saltwater pearls on a large scale in the 1980s using the species Pinctada chemnitzii, and they are known as Chinese Akoya pearls. After decades of development, Chinese production represents about 80% of the Akoya pearl market worldwide. Large numbers of Chinese Akoya pearls are pouring into Japan. Although cultivation techniques in Japan are still better developed than that of China, due to the lower cost of Chinese materials, factories in Japan are increasingly targeting China as their main pearl source.
Akoya Pearl Colour
The classic colors of Akoya pearls are white, creamy and black. However, there are, actually, no naturally black Akoya pearls; the color is permanently created through an irradiation process. In addition to the classic colors of white and creamy, a variety of rose, silver and ivory overtones adds diversity to available colors.
Akoya Pearl Size and Luster
As the Akoya oyster is the smallest of all species of pearl producers, Akoya pearls are also smaller. The average diameter of an Akoya pearl ranges between 4-9mm. An Akoya pearl of 9mm or more is very rare and extremely valuable and from that point even a slight increase of 0.5mm in diameter can result in a huge difference in value.
As the shape of Akoya pearls is quite uniform, all round or near round, a strand of Akoya pearls is much more likely to be very nicely matched. High luster is another hallmark of Akoya pearls, due to the cultivation and processing techniques that have been painstakingly developed for over 100 years.