What is Japanese Akoya pearls
Japanese akoya pearl is the name given to all akoya pearls. Japan is the country where it was cultured first. They were the first cultured pearls, farmed using a bead and mantle tissue technique by Kokichi Mikimoto of Mie Prefacture, Japan, 1916. These Pearls are famous for their round shape and luster and they are also known as classic pearls.
Akoya Pearl Mollusc
These pearls comes under the category of saltwater pearl. Akoya pearls produced inside a bivalve mollusc of Pinctada Genus. Primary species used in farming is Pinctada Fucata, specifically the subspecies Pinctada. Martensii. They are smallest of all pearl bearing oysters. P. Martensii also called the “white butterfly” shell, because of its highly iridescent,creamy white to bluish white mother of pearl found on the interior of the shell.
The P. Martensii is grows only up to 7-8 cm in diameter at maturity. These molluscs harvested in a environment where hard, strong oysters can be produced so that they are capable of producing high quality pearls.
Low temperature of the sea water is very ideal for culturing the akoya pearls and the cold temperature of pacific ocean surrounding the Japan fulfill this requirement. Cold temperature slows down the metabolism of P. Martensii which results in the formation of very fine quality nacre which has very compacted layers.
Culture of Akoya Pearls
For the last hundred years Japan is undisputed leader in producing akoya pearls. Quality of Japanese akoya pearl is so fine that it has became the benchmark for other akoya pearl producing nations, like Vietnam and China. The technique of nucleus insertion, which was developed by William Saville-Kent and used by Mikimoto hundred years ago, the same technique is used today in akoya pearl farming.
Japan was the sole nation in producing akoya pearls but gradually in 90’s Vietnam and China also entered in akoya pearl farming. Both of these nation use Pinctada Chemnitzii oyster. Vietnam started harvesting of P.Chemnitzii in 2001.
Until 2007, Japan lost most of its market share to China. At one time, China was making almost equal quantity of akoya Pearls and their quality was very competitive to Japanese Akoya Pearls. But in 2008 and 2009, Mother nature destroyed Chinese akoya pearl farms. Heavy storm destroyed everything, and all the Farmers abandoned their farms.
Characteristics and Grading
Akoya pearls oysters are either from Japan, China or Vietnam, all their characteristics are same. They produces pearl of almost same size and features. The pearl size ranges from 2mm to 11mm, but the most common size in which they are found is 6mm to 8mm. When their all features are same, then size play the role in deciding the price of the pearl.
What are Hanadama Pearls
These are those pearls which are so fine in appearance and quality of nacre that they are immediately set aside after harvest. These pearls are best in every value deciding factor except size. But, even two best pearls are not identical, so quality range within Hanadama pearls exist.
Value of Akoya Pearls is based on following Factors
The value of akoya pearl is decided by six following factors:
Akoya pearls typically comes in the size range of 2-11mm but the most size is 6-8mm. When all the other characteristics are identical then size decides the value of the pearl.
Akoya pearl oysters are grafted with perfectly round shape beads on which the nacre deposited, so the pearls are perfectly round. Other shapes like drop, oval or baroques also exist but they are not very common.
Akoya pearls are mostly white but sometimes they have overtone of rose cream or silver. Overtone can be defined as, the secondary color appears to shimmer over the main body color of the pearl.
Akoya pearls popular for their mirror like luster. Luster is the most important factor in deciding the value of akoya pearl. A pearl with strong luster having some blemishes is more costlier than pearl having clean surface but poor luster.
The luster value contain five categories: excellent, very good, good, poor and Fair.
Surface condition of the pearl rate the value of the pearl. While akoya pearls are rarely blemish-free, when other value factors are equal then the pearl which has least blemishes on the surface, higher the value of the pearl.
Nacre quality depends on three factors:
Acceptable: the nucleus of the pearl is not visible.
Nucleus visible: Blinking is visible when the pearl is rotated and the bead is noticeable.
Chalky appearance: The pearl shows an obvious dull appearance.