About Pearl |
Kokichi Mikimoto
Born January 25, 1858 in Toba, Mie Prefecture. He started pearl farming around 1890, and finally succeeded in culturing semi-circular pearls in 1893. After that, he overcame many hardships and developed cultured pearls as his jewelry industry, which is too famous. He is a person who has made a fortune by cultivating pearls and branding them. He is the founder of Mikimoto Pearl Shop (now Mikimoto ). He was also called Mikimoto Pearl, King of Pearls.
pearl oyster
(Akoya pearl oyster,
Pinctada fucata)
A marine bivalve that produces Akoya pearls, the origin of cultured pearls. The same species is widely distributed from the Indian Ocean to the western Pacific Ocean. In Japan, the northern limit is said to be the Boso Peninsula on the Pacific Ocean side and the Oga Peninsula on the Sea of Japan side. The inner surface of the shell has a very beautiful iridescent luster.
White lipped pearl oyster
(Silver/Gold-lipped pearl oyster,
Pinctada maxima)
A large marine bivalve that inhabits the Indian Ocean centered on the equator from Amami Oshima to the south, and the Southwest Pacific Ocean. They are called silver lip and gold lip due to the difference in color of the rim of the mother-of-pearl. It is the largest shellfish used for pearl farming, and most of the cultured pearls are large pearls of 10 mm or more.
Black-lipped pearl oyster
(Black-lipped pearl oyster,
Pinctada margaritifera)
This is the second largest pearl cultured mother oyster after white lipped pearl oyster. In Japan, it lives south of the Kii Peninsula. In the world, its habitat ranges from Taiwan to the West Indian Ocean, the Persian Gulf, the Red Sea, the South Pacific (Micronesia and Polynesia) to the Gulf of California and the Gulf of Panama.
Mabe
(Black-winged pearl oyster,
Pteria penguin)
A large marine bivalve with a distinctive shape like an eboshi. Widely distributed in the Pacific Ocean and Indian Ocean waters south of Amami Oshima. Since ancient times, attempts have been made to cultivate pearls using this type of shellfish, but it was difficult to cultivate perfectly round pearls, and half-shaped pearls were mainly used.
Hyriopsis cumingi
(Hyriopsis cumingi)
A large freshwater bivalve that inhabits the rivers and marshes of China. A close species of Hyriopsis schlegeli that lives in Lake Biwa, Japan. In China, a large amount of mother oysters are produced by artificial seedlings and used for freshwater pearl farming. In China, it is called "Triangular Fan Pass".
Conch pearls
Natural pearls produced from binkugai. It has a special cross-plate structure that is different from the normal pearl structure. There are many oval types. It is characterized by a red color derived from carotenoid pigments and a flame structure.
●How pearls are made
Pearl oyster soft body
The soft body contains various organs such as the heart, carp, adductor muscle, mantle, and gonads. Of these, the mantle and gonads are essential for pearl farming. From the mantle, small pieces of cells called "pieces" are cut out and transplanted into the gonads along with the nucleus to form pearls.
Piece
A cell fragment cut from the epithelial cells on the outer surface of the mantle, usually about 2 mm square. The pieces are transplanted into the pearl oyster body together with the nucleus, proliferate to form a pearl sac, and secrete nacre to produce pearls.Recent research has shown that the properties of the pieces are greatly related to the color of the pearls, and the characteristics of the oysters from which the pieces are cut are emphasized
Artificial Seedling
Artificially fertilizing male and female shells to create and nurture juvenile shells. In pearl oysters, seed oysters are usually reared from late December, and after they have matured sufficiently, sperm and eggs are extracted from the gonads in late January of the following year and fertilized. grow until After that, they are taken out to sea for farming. Parent oysters are carefully selected to produce excellent mother oysters. Recently, various biotechnologies have been introduced, such as investigating the characteristics of the mother shellfish at the genetic level and cryopreserving sperm.
Natural Seedling Collection
Collecting young oysters that have been naturally fertilized and raised in the sea and growing them into pearl oysters. In the case of Japanese pearl oysters, the young oysters that are newly born from early spring to early summer enter an adhering life. Aiming at this time of year, sticks such as cedar leaves are soaked in the sea, and juvenile shells are attached and collected.
Nucleus insertion surgery
It is no exaggeration to say that the quality of the pearls produced is largely determined by the skill of the surgery, which is the most important step in pearl cultivation. It is astonishing that the technique of transplanting living tissues called pieces was established more than 100 years ago.
Cultivation Management
Mother tools that have undergone nucleus implantation surgery are cultivated in earnest, but the method of managing mother oysters during the culturing period also has a large impact on the quality of the resulting pearl, just like nucleus implantation surgery. . Recently, efforts have been made day and night to scientifically understand the physiological characteristics of mother oysters and the environment of fishing grounds to produce high-quality pearls.
Hamagage
Harvesting pearls from cultured pearl oysters. It is also called "Hamaage". Beached pearls are called hamaageju. In the case of Japanese Akoya pearls, beach-age is carried out from December to February of the following year, when the color and luster improves. After culturing, the mother oysters are transported to land for pearl collection, and are hauled off the beach. Farmers carry out the hamaage with anticipation and anxiety in their hearts, wondering what kind of results their daily efforts will bring to Tama.
Akoya Pearl Farm (Japan)
Akoya pearl farming was once practiced in Kanagawa prefecture on the Pacific Ocean side and 24 prefectures west of Ishikawa prefecture on the Sea of Japan side. Nagasaki, Kumamoto, and Oita prefectures are the main prefectures.
Pearl Selection
Pearl selection is based on quality such as shape, winding, flaws, luster, and color.
Pearl drilling
Drilling includes double drilling for continuous use and single drilling for crafting.
string
On a rectangular wooden tray with grooves called rendai, double-hole beads are lined up according to quality such as size, shape, winding, scratches, and color, and threaded to make a single necklace. ¡The quality of the pearls is aligned on the ream stand to make one ream. Very skilled technique is required.
●Pearl Shapes
Even if a round nucleus is put into a mother oyster, the resulting pearls come in various shapes such as round, semi-round
, drop, and baroque. be done.
There is not much research
as to why these different shapes are possible
●Pearl Color
The color of pearls varies depending on light interference, pigments, and organic matter.
gradient
A necklace in which the largest pearl is placed in the center and the pearls are symmetrically arranged so that the size gradually decreases from there. In the case of Akoya pearls, there are types such as 2.5, 3.5, 5, and 8 types, depending on the size, length, and weight of the pearl.
uniform
Necklaces of nearly equal size, strung together with beads within 0.5mm in size. There are various names depending on the length.
Pearl necklace length
Necklaces (uniforms) are called by various names depending on their length.
●Choker ①: 14 inches (approximately 35 cm).
The perfect length for your neck.
●Princess: 16 inches (approximately 40 cm) to 17 inches
(approximately 43 cm).
● Matinee ②: 21 inches (approximately 53 cm).
1.5 times longer than a choker.
● Opera ③: 28 inches (about 71 cm).
Originally for evening parties.
● Rope ④: 42 inches (approximately 107 cm).
Three times the length of a choker.
mother of pearl
A layer of crystals of calcium carbonate called aragonite and hard proteins called conchiolin that are stacked in parallel like the bricks and cement of a brick wall.
winding
nacre thickness. The standard for winding differs depending on the type of mother shellfish. Rolls are generally related to the cultivation period, and the longer the cultivation period, the thicker the rolls tend to be. Soft X-rays are often used to measure windings non-destructively.
Terri
Teri The quality of light reflected by pearls is called teri. The quality of a pearl's luster is determined by the pearl's surface structure and internal structure (thickness, uniformity, light transmission, etc.). When the surface of the pearl has a smooth surface without irregular reflection of light, and the beautiful large and thin aragonite crystals are piled up regularly to form the nacreous layer, the effects of light reflection, refraction, interference, etc. Terry is born.
Hanadama
Cultured pearls generally refer to high-quality cultured pearls with few flaws, good shape, curls, luster, and color, but there are no clear standards. Almost 90% of the mussels die during the cultivation period after the nucleus insertion surgery. The reasons for this are physical exhaustion, the shock of surgery, and damage from red tides, typhoons, and infectious diseases. The remaining 20% or so of shells are of low quality and have no value as jewelry. The last 30% of oysters produce quality pearls. Among the good quality pearls, only 10% are the highest quality pearls called “hanadama.”
Bleaching
Bleaching the pigments and organic substances called "blemishes" contained in the pearls, mainly using an oxidizing agent such as hydrogen oxide, to bring out the beauty of the pearls.
It is said that the bleaching of pearls was inspired by the use of oxyflu in coral bleaching in Italy.
Non-nuclear cultured pearl
A pearl cultured by inserting only a piece into the mother shell. It is called nucleusless because it does not use a solid nucleus. Most freshwater cultured pearls are nucleus-free.Pearls artificially manufactured to imitate the appearance, color and other characteristics of natural or cultured pearls Whether or not they have the same physical and chemical characteristics as natural or cultured pearls It doesn't matter.
Nucleated cultured pearl
A pearl cultured by inserting a nucleus and pieces into a mother shellfish. Almost all marine cultured pearls are nucleated. A small number of cultured freshwater pearls also contain nucleated pearls.
Akoya pearl
A pearl cultured with pearl oysters. The size is about 2 to 10 mm, and 6 to 7 mm is common. Large beads of 8 mm or more are extremely rare. Many of them have a unique interference color. Besides Japan, Akoya pearls are also cultivated in China and Vietnam.
Black Butterfly Pearl
A pearl cultured with Black Butterfly Shell. In the 1970s, Ishigaki Island in Okinawa was the main production area, but in the 1980s Tahiti began mass production, and now most of it is produced in Tahiti. In the past, most pearls were 10 mm or more, but recently they have increased by 8 to 9 mm. As for the color, the reddish green-black called "peacock" is the most preferred
. In addition to this, there is a wide range of colors such as black, gray, green, red, white and blue.
white butterfly pearl
Pearl cultured with white mussels. It is also called "South Sea Pearl". Most of them are 10 mm or more in size, but recently 8 and 9 mm ones are increasing. White pearls include white pearls called "silver-lipped" pearls cultured in shellfish, and cream-golden pearls called "gold-lipped" pearls cultured in shellfish. White butterfly pearls are mainly farmed in Australia, Indonesia and the Philippines. Recently, it is also farmed in Myanmar and Japan.
Freshwater pearls
Pearls cultured with Ikechogai in Japan and Triangular oysters in China. Recently, there are very few products made in Japan, and most of them are made in China. Most freshwater cultured pearls are nucleusless, so they come in a wide variety of shapes.
The three basic colors are white, orange, and purple, and these are mixed to create a variety of colors. The size ranges from 2 mm to 10 mm or more, and the width is wide.
Cultured pearls
Cultivated pearls that are formed in the body of a living mollusk due to artificial factors, and whose entire visible surface is covered with nacre. Artificial intervention within the concrete only gives the opportunity for the formation of pearls, and the formation is only natural products produced within the concrete. Cultured pearls are categorized into
cultured pearls and semi-circular cultured pearls according to their formation mechanism and characteristics.
Hemispherical pearl
A pearl cultured by inserting a hemispherical nucleus into the inner nacre layer of a pearl oyster shell. After culturing, the core is removed and filled with resin or the like. Since mabe-cultured pearls are famous, half-shaped pearls cultured in white-lipped oysters, black-lipped oysters, and abalone are often called 'mabe'. It used to be called "half-round pearl" or "radius pearl", but now it is unified as "half-shaped pearl".
Natural pearls
A metabolite formed in the body of a living shellfish without any artificial factors, and whose visible parts are equivalent to shells. Say. Natural pearls can be divided into those with a nacreous structure and those with other structures (eg cross-plate structure).
Poppy
Non-nucleated seawater pearls harvested as a by-product of cultured pearls Keshi used to refer to small non-nucleated pearls harvested from Akoya oysters, but today it also includes large non-nucleated pearls harvested from white and black oysters. called poppies.
Momme
An ancient Japanese unit of weight for measuring the weight of pearls. Momme = 3.75g. Since cultured pearls originated in Japan, the momme (monme) is still an exception and is accepted as a unit of weight.