Black Lipped Pearls

Pearl foundation

History of Pearls

Pearls are an incredibly unique gemstones. While most precious gems are formed in the ground, surrounded by rocks, pearls are the gemstones created inside of a living creature. Pearls are therefore sometimes called bio minerals.

Pearls have been revered since approximately five thousand years ago in all over the world, for its natural glistening beauty placed onto oyster beds.

A Chinese philosopher, Confucius wrote in his book “Book of Documents” that fresh water pearls were presented as gifts to Chinese royalty as early as 2,206 BC (4,186 years ago). While in Europe, from ancient Rome, pearls are often quoted in bible verses. For instance, in the New Testament, the verse states as " Again, the kingdom of heaven is like a merchant in search of fine pearls. When he found one very precious pearl, he went away and sold all he had and bought it” (From The New Testament, Matthew). Pearls have been known as the “Queen of Gems”, and pearls have been coveted for centuries in the form of jewellery.

Before cultured pearls were introduced, the only way of collecting pearls was through diving to retrieve the pearl oysters. Pearl jewellery therefore, was considered the ultimate status symbol for royalty and the ruling class for being the rarest gems.1

*Portraits of royalty and authorities with pearls

Today, pearls are named as five precious stones along with diamonds, rubies, sapphires, and emeralds. Pearls have long been worn by women, and in modern age, pearls are used not only in formal occasions but also worn with casual, everyday clothes, gaining popularity among women. The origin of the diversification of pearl jewellery generally dates back to the first half of the twentieth century, when Coco Chanel launched her collection incorporating imitation pearls. Coco Chanel was a sensational pioneer in teaming her pearls with casual daywear. 2

Definition of Pearls

“Imitation pearls” have grown popular lately and you might have often heard about them. Some faux pearls, such as cotton pearls, the difference can be seen at a glance when compared to genuine pearls (stated as "pearls" for convenience here). The differences between imitation pearls and pearls are their price, weight, texture, and the most notable difference is how they are manufactured. The definition of pearls determined by the pearl trading market is introduced here.

Pearls are defined as “metabolites produced by living oyster that can form nacre, and their visible components are the same as the mother of pearl which has bright and clear nacre inside the shell.” To qualify as pearls, first, pearls must be formed in a “living shell” with bright and clear pearlescent inside shells, like abalone, oysters, black lipped oysters and White lipped oysters. Second, the shining part of the inside shell called “nacre” must form layers around pearls covering the whole gem.

*Inside of black lipped oyster and black lipped pearls

How Nacre Works

Pearls are formed when nacre, the same component found on the external surface of a pearl and the internal lining of shells, forms layer upon layer of this coating. As a defense mechanism, nacre is used to coat the irritant and layers of nacre form around the nucleus. Therefore,  when the time of mother oyster spent underwater before the pearl was harvested becomes longer, the size of pearl grow bigger. There are several other factors affecting the size of pearl such as the size and vitality of the mother oyster that produced the pearl and the size of the nucleus, but generally speaking, larger pearls spent longer time in their shells before they were harvested.

Nacre is Composed Of “Calcium Carbonate” and “Protein”

Nacre is consisted of "crystallized calcium carbonate that account for 95% of the nacre" and ""calcareous proteins called “conchiolin”". The structure of nacre resembles a brick wall at the microscopic scale: Calcium carbonate platelets ('bricks') alternate with conchiolin layers ('mortar').

While the solid platelets serve as the load bearing and reinforcing part, energy can be dissipated into the soft polymer segments. Together, nacre is composed of layers of calcium carbonate platelets and conchiolin layers arranged in a continuous parallel lamina.

*Enlarged image of surface of black lipped pearl

*Reflection of light and nacre

Since conchiolin has a low penetration of light, pearls with many conchiolin have poor luster quality and weak reflections that are quite blurred.

Therefore, the high quality nacre must be composed with minimum amount of conchiolin to penetrate the light, and nacre plate should be packed with: even shaped, no lack, maximally large calcium carbonate crystals to reflect the lights desirably. Layers produced by high quality nacre reflect more lights from the inside, resulting more luster in pearls.

* The correlation between the thickness of nacre and pearl luster Cultured for approx. 6 months (left), approx. 24 months (right)

“Luster is the Most Important Characteristics for Pearls ”

Luster is the reflection and refraction of light as it passes through layers of aragonite. The intensity of a pearl's luster can be an indicator of nacre thickness. The special shine pearls possess is called “luster”. Luster does not simply refer to pearl’s shine. According to “Pearl Dictionary” supervised by renowned Hiroshi Komatsu, luster is defined as:

"The beauty of gemstones is defined subjectively, but generally speaking, the beauty is determined based on five optical effects: cut, shape, color, transparency, and luster. The gems listed in the five precious gems also share these effects. (Omitted) Gems like ruby and sapphire can produce beautiful optical effects such as asterism (star effect). High quality pearls have a strong “luster”. The term “luster” is different from the luster of mineral based gemstones, and refers to the color with brilliance, or interference color. This is due to the interference of light, which is created by the neat stacking of the nacre. This optical effect is probably the biggest reason why pearls are praised as beautiful gems. 』3

Black lipped pearls have a famous color called "peacock color" with a green rim and a red overtone. This is formed by the overlapping of colors, created by the pigments contained in one layer of nacre reflected with light and stacked in multiple layers. The pearl with this beautiful interference color-"luster" has a very high quality of nacre, which proves to be a durable, long-lasting and good quality pearl. This is why pearl dealers often say that “Luster is the Most Important Characteristics for Pearls”

*Famous “peacock color” of black lipped pearl

*Black lipped pearl with high luster

*Black lipped pearl with hazy luster

*Black lipped pearl with blurred luster

Pearl Grading

Pearls are graded on six criteria: Luster, nacre thickness, Surface, Flaws(Blemish), Shape and Color. The final grade is given after all six criteria have been evaluated.

LUSTER - Luster measures the rate of reflection on a pearl’s surface, and the amount of light reflected on the pearls. Luster is sometimes referred to the most important value factor when grading pearls. The overtone color and body color should look different when pearls with superior luster are held horizontally at eye level. Nacre thickness - Nacre quality refers to indentations in the nacre. For beautiful, thick layers of nacre requires dedication of pearl experts and great underwater environment. More nacre layers result in better grades. SURFACE - Pearls that feature clean surfaces without inclusions like chalky spots and wrinkles will be much more highly valued than pearls with multiple blemishes. Pearls with nacreous layer like mirrer like quality receive better grades. FLAWS(BLEMISH) - Pin-pricks are sometimes referred as pearl’s dimple. Since pearls are a product of nature however, there will always be some form of blemish such as pin holes, scratches and dents. Almost all pearls have some sort of blemish and pearls with less blemishes will be much more highly valued than pearls with multiple blemishes. SHAPE - Pearls come in multiple shapes and they each have names. As people say “Pearls are round”, some pearls come in round shape, others come in the shape of rain drop, button, Keshi, or smooth. Lately, flat pearls called flake and unevenly shaped pearls called baroque are gaining popularity. COLOR - Color of pearls depends on the color of mother oyster. Akoya pearls tend to have yellow and pale peach color and black lipped pearls have countless, multiple colors.

Pearl Processing

Pearl treatments can be roughly divided into two types: “treatments for enhancing pearl’s natural beauty(1)” and “treatments to add and create pearl’s beauty artificially(2)”

The first enhancing treatment(1) is often referred to as makeup for pearls, 1. " Pre-processing ", mainly performed in the subsequent process with the intention of facilitating the penetration of the solvent. 2. “Drilling”, For Akoya pearls, holes are drilled in the pearl for easier solvent soaking. 3. "Stain removal" , to remove impurities that have entered between the nucleus and the nacre. 4. “Bleaching”, in order to remove the color pigment found in pearl protein. 5. “Minute dyeing”, gentle dye is used with alcohol to bring out the original color of the pearl.

The second type of pearl treatment(2) is sometimes referred to as plastic surgery for pearls. This treatment uses the same processing technique of 1 to 4 above, and in addition, coloring treatments that change the color of pearls by chemical reactions such as strong dyes or silver nitrate, or coatings that protect pearls from sweat or acid, or increase the surface texture of pearls are conducted.

Most Akoya pearls currently on the market are chemically treated to enhance their natural beauty. (According to the Fisheries Agency's “Special Issue on Pearls-Fisheries” (issued in 1958), the percentage of Akoya pearls that can be used without processing is about 15%.)

Philosophy of Seibido Pearl

Seibido Pearl consider beautiful pearls to be "pearls with multiple high quality, fine and transparent nacre layers." We consider “luster” and “Nacre thickness” as our biggest value factors.

High luster is a sign of good pearls. High quality pearls do not fade or become hazy even after many years. Rather strangely, at Seibido Pearl, we have witnessed pearls with higher quality tend to gain more lustrous over time.

In addition, Seibido Pearl only offers unprocessed black lipped and White lipped pearls. Pearls have all-natural colors and have not been subjected to any chemical treatment such as toning, dyeing or even any types of pre-treatment. If processed, the delicate structure of the pearl becomes unstable, and external stimuli may cause unexpected changes in quality. We believe that high-quality pearls are naturally full of brilliant vitality and shines beautifully without being processed.

Pearls grow older with customers, and pearls should maintain the same quality as they were first harvested.

As a company passing down the story of pearls to customers, it is our mission to guarantee the quality of pearls until they reach our customers, and we have been proudly building trust with customers.

[1]『真珠』白井祥平著 海洋企画
[2] [3] 『真珠辞典 真珠、その知られざる小宇宙』小松博監修 白子修男発行 繊研新聞社

Black Lipped Pearls

The pearl oyster of black lipped pearl is black lipped oyster, scientifically named as Pinctada margaritifera.
Most pearls in ancient Europe, including a pearl in the famous painting of Johannes Vermeer’s “The Girl with a Pearl Earring”, were black lipped pearls. Back then, pearls were called Margarites in Greek and they were called Margarite in English. The scientific name of the black lipped shell, “margaritifera”, is based on such etymology.

Black lipped oyster is the second largest pearl oyster after the White lipped oyster. Black lipped oyster has the dark green coloring along the margins of the interior of the shell that shines in all the colors of the rainbow with sunlight.

The thickness of one layer of nacre produced by the black lipped shell is as thin as 0.3 to 0.6 ㎛ (micrometers), and its quality is also very condensed. The nacre layer of Akoya pearl is considered to be particularly thin among pearls, is actually about the same as black lipped, 0.2 to 0.4 ㎛. Black lipped pearls have been attracting people for their beautiful, natural overtones that thin layers of nacre produce.

The size of black lipped pearls is about 9 to 10 mm, slightly larger than Akoya pearls. Due to the repeal of export control law led by the Tahitian government (* 1), pearls large as 12 to 13 mm have been decreasing in recent years.

*Exterior and interior of black lipped oyster

(*1) Export Control Law of Tahitian Pearls
Tahitian grown black lipped pearls are considered the most beautiful black lipped pearls in the world due to their geographical uniqueness and the biological superiority of the inhabiting black lipped oysters. Since the late 1990’s, the French Polynesia government (Maison de la Perliculture) has mandated that all exported Tahitian pearls must be inspected via X-ray and certified to have at least 0.8mm of nacre on each side of the pearl to ensure the quality of Tahitian pearls. This law was repealed however, due to strong demands from local pearl farmers in 2017, allowing any pearls to be exported.

* Cross section through black lipped pearls / Cultured for approx. 6 months (left), approx. 24 months (right)
Difference in thickness of nacre layers is present

Colors of Black Lipped Pearls

Perhaps because of the strong impression of “black” in the name of black lipped pearls and black lipped oysters, people often imagine black lipped pearls are only dark colored pearls as their name suggests. In fact, In Japan, dark colored black lipped pearl necklaces are often seen at ceremonial occasions such as weddings and funerals, adding the formalness to the look.
However, if you carefully observe a black lipped pearl necklace, you can see that there are multiple colors (interference color) such as red and green, different in each pearl. These are the original colors of black lipped pearls.

The colors come in endless, such as red, green, orange and pistachio colors, and this wide range of pearl colors is one of the charms that only black lipped pearls have.

*All natural colors of black lipped pearls

Pearl color is determined by several factors. One of them is the protein pigment of the mother oysters. When the pigment of the pearl oyster’s protein is yellow, it produces pearls like South Sea pearls and Akoya pearls, in white to cream and slightly pink colors. Black lipped oysters have three primary color pigments, red, blue and yellow, which allows them to produce a full color spectrum.

* “Peacock color”, one of the most popular color of black lipped pearls

The peacock color has interference colors of green at the outer edge and red at the body, has been highly valued color of black pearls in the industry trade. Vivid hues of peacock colored pearls resemble divine beauty of peacock feathers.

Shapes of Black Lipped Pearls

Black lipped pearls have a higher deformation rate than Akoya pearls due to the structure of mother oysters. Black lipped pearls have a characteristic of possessing rich variety of shapes, such as teardrop shape and circled pearls. The combination of rich colors and unique shapes can vary, and unless they are artificially processed, pearls will never be exactly the same shape.

*teardrop shaped black lipped pearl

*Circled black lipped pearls

The pearl design experts carefully consider the combination possibilities among all the harvested unique black lipped pearls (* 2). Pairing special shapes that are not round is particularly difficult and even skilled designers take a considerable amount of time.

For example, drop shaped pearls are often used as earrings and pierced earrings, but the probability of oysters forming an ideal drop shaped pearl is extremely low, and finding a perfect pair of pearls from countless combinations of colors and shapes is extremely difficult. Matching a pair can take years, depending on size and color. A pearl to find its match is almost a miracle.

*Drop shaped pearls being paired

Some skilled pearl designers who handle pearl selection, pairing, and grouping remember all the pearl “faces” by looking just once. Even if she/he happens to see a pearl worn by a woman passing by on the street or on a photo she/he happens to see on social media, skilled designers can easily tell if they have seen the pearl already or not. This amazing skill has been acquired through working with pearls every day.

(* 2) “Pairs” and “Necklace making work”
Pairs: Matching pearl shapes and colors in 2 pieces of pearls for earrings and pierced earrings.
Necklace making work: Grouping of pearls for necklaces. For a pearl necklace, we usually select and group around 30-46 pearls in uniform hue and shape.

Production Areas of Black Lipped Pearls

*Map of Tahiti

Tahiti, located in French Polynesia, is one of the largest farming areas that make up about 95% of the total cultured black lipped pearls produced. For this reason, black lipped pearls are also known as “Tahitian pearls”.

People often think of Tahiti as a tropical island, but Tahiti has a variety of small and large islands located from 14 degree to 23 degree South latitude, and the Gambier Islands, which are located at the southeast terminus of the Tuamotu Archipelago, has a lower temperature and water temperature than typical tropical islands. When the water temperature is low, the nacre forms thin and more beautiful pearl layers compared to other areas where the black lipped oysters can live. Tahiti has a particularly low water temperature, is famous for its beautiful black lipped pearls.

For example, Mangaleva Island, located in the Gambier Islands, has a number of conditions suitable for culturing pearls. First, the island has a large lagoon; second, the water temperature is low located in the southernmost island of Tahiti and third, rich nutrients from the 500-meter-high mountains are poured into the lagoon in Mangaleva Island. The island is an ideal island for culturing black lipped pearl.

* A lagoon ofGambier Islands, claimed as “the most beautiful lagoon” in Tahiti

Black lipped pearls are also cultured in the Cook Islands, Fiji and Okinawa, but the size, environment and high water quality of the Tahiti lagoons are by far make the best cultivation area, and their superior environment is the reason 95% of black lipped pearls are produced there.

*Insertion of the nucleus into black lipped oysters.

*oysters are polished carefully everyday to keep away bacteria.

Even when the environment is perfectly suitable for pearl cultivation and for mother oysters to live, if there are too many pearl farms culturing in the area, nutrition underwater will be depleted and the health of the mother oysters will be jeopardized.

Placing the pearl oysters in the farm alone will not make a good enough environment, as bacteria will start grow inside and cause illness, or nutrition for each oysters will not be evenly distributed unless oysters place are rotated.

Beautiful pearls are formed and grown by healthy pearl oysters. To form beautiful pearls, mother oysters must be strictly managed by the farms.

For this reason, pearl farmers work hard every day to create a better environment for pearl oysters, by picking up the pearl oysters from underwater and carefully polishing them one by one and adjusting the position of the pearl oysters for them to rotate. The quality of Tahitian pearls is maintained by the efforts of local farmers.

Delivering the Original Beauty of Pearls

The president, Koji Isowa, grew up being surrounded by pearls from an early age, and has nurtured the aesthetic eyes and sense of beauty to pearls. While he saw many pearls, Akoya pearls before being “minute dyeing” caught his eye. Akoya pearls are usually processed, but the natural colors are very attractive. He then had a dream to deliver jewellery made with unprocessed pearls for people to enjoy “their own natural beauty”.

President Isowa joined Seibido Pearl in 1995. The processing technology for dyeing and “minute dyeing” pearls at that time was about to advance further. Around in 1996, pearls were being dyed in gold without leaving any holes on the surface and the processing technology called pre-processing started to advance. (*Please see to “Knowledge of Pearl” section for details of pearl processing) The problem was that in most cases, information on how pearls were processed was almost never disclosed and adequate information was not available then. President Isowa saw the situation back then as a problem in the market upon joining Seibido Pearl and sought for a solution to change it.

President Isowa determined that stopping the minute dyeing and dyeing of Akoya pearls was not possible since the treatment process has become standardized. He instead focused on black lipped and White lipped pearls. Black lipped and White lipped pearls then were mainly harvested in natural colors, and dyeing and minute dyeing had only just begun for these types of pearls. In addition, some selected black lipped and White lipped pearls have natural colors and luster already perfect for jewellery without any treatments such as dyeing or minute dyeing. President Isowa was convinced that the original beauty of black lipped and White lipped pearls can be made into jewellery and he prioritized investing in these types of pearls.

Consequently, President Isowa decided to focus on naturally colored Black lipped pearls. In 2001, Seibido Pearl made an official commitment to customer that only non-toned and undyed pearls will be offered as the “promise of Seibido Pearl.” This commitment to offer only the naturally colored pearls is shown in the collections of mabe pearls with natural brown gold colors, Super Peacocks, signature collection of Seibido Pearl, and S-line Peacocks as a result.

Seibido Pearl, as a leading company that offers the original beauty of pearls, will continue to offer un minute dyeing and undyed black lipped pearls and White lipped pearls.

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