Pearl – eikopearl

Akoya Pearl

Cultivation of Akoya pearls mainly takes place in the seas of Mie, Ehime, Nagasaki, and Oita prefectures in Japan. The cultivation period is typically within a year, usually around 10 months. The grafting procedure is carried out around May or June. Harvesting of the pearls usually occurs from November to January of the following year. Among the pearls harvested within a year, they are referred to as "current-year pearls." On the other hand, pearls that have been cultivated for over a year are known as "over-year pearls". Generally, over-year pearls tend to exhibit thicker nacre layers and greater beauty compared to current-year pearls. However, as the cultivation period extends, there is an increased likelihood of stress on the oysters, which may result in pearl expulsion, susceptibility to diseases, and higher mortality rates.

From round and semi-round to drop, button, baroque, and circle shapes, Akoya pearl offer a diverse range. It is said that Akoya pearl have a higher probability of becoming round compared to other pearls, thanks to the fine crystalline secretions of the oyster's mantle.

The sizes of Akoya pearl range from approximately 3mm to 10mm, with the main size falling around 8mm. This places them in the mid-range compared to other types of pearls. Pearls larger than 10mm are quite rare, and it is common to find pearls in the range of 7-8mm.

Akoya pearls come in varying colors due to pigments in the conchiolin layer.. Akoya oysters, containing yellow pigments from Akoya clams or yellow-mouthed turban shells, often produce pearls with yellowish tones. Pearls from shells with fewer yellow pigments yield pure white pearls. The color of pearls is a result of the combination of intrinsic color and iridescence, known as interference color. As a result, each pearl is unique, and even pearls from the same strand may appear differently depending on the lighting conditions and environment.

The term 'blemish' in pearls refers to natural protrusions or indentations that occur on the surface during the cultivation process. Almost no pearls are completely flawless, and careful consideration is given to selecting the location for piercing. By assessing the balance of blemish location, color, and luster, pearls are categorized as suitable for single or double piercing. The ranking of blemishes is based on factors such as quantity, size, and location, dividing them into categories like flawless, minor blemish, moderate blemish, and major blemish, with fewer blemishes considered more desirable.

Pearl color is influenced by both the intrinsic color of the pearl itself and the interference color caused by the interference of light. Akoya pearl have a layered structure with extremely thin crystals of calcium carbonate, each layer ranging from 300 to 500 nanometers. When light enters this 'pearl layer,' it undergoes reflection or transmission at each layer of crystals, leading to the occurrence of light interference. The combination of light reflection on the pearl's surface and this 'interference color' results in the unique luster of pearls that we perceive as 'Luster.'

Winding is the formation of the nacre layer around the nucleus by the Akoya oyster. Japanese Akoya pearl is known for their high nacre transparency, created by layers of calcium crystals and organic matter. The structure and pigment content of this layer determine the pearl's color and luster. The dense nacre layers in Japan's seas, influenced by the four seasons, result in the unique interference colors of Japanese Akoya pearl.

South Sea Pearl

The mother oysters that give birth to the South Sea Pearls come in two varieties: Silver-Lip and Gold-Lip. In Australia, the variety known as Silver-Lip is more common among the white-lipped pearl oysters. These tend to produce large pearls in white hues. On the other hand, in Indonesia, the Philippines, and Myanmar, the Gold-Lip variety of the white-lipped pearl oysters is more prevalent, leading to the creation of pearls in gold and yellow shades. Both varieties are cultivated in the warm waters of the southern seas. Due to the large size of the white-lipped pearl oyster, pearls produced are generally larger compared to Akoya pearls. Moreover, with a cultivation period of nearly two years, these pearls have thicker nacre and a more profound, lustrous shine compared to Akoya pearls.

The rich variety of shapes is also one of the charms of White South Sea pearl. They come in a diverse range of shapes, including round, semi-round, drop, button, baroque, and circle.

White and silver-tone pearls come in sizes ranging from 8mm to around 20mm, but the mainstream sizes typically range from 10mm to 15mm. While there are occasional occurrences of pearls exceeding 20mm, such large pearls are extremely rare and hold high rarity value. Yellow and golden-tone pearls, being produced by slightly smaller oysters, range in size from around 7mm to 17mm.

From the 'Gold Lip,' predominantly yellow, cream, and gold-tone pearls are produced, while the 'Silver Lip' yields mainly white and silver-tone pearls. The color variations include pink-white, silver-white, white, gray, yellow, and gold, offering a diverse range.

Even in cultured pearls, being gems nurtured by nature, the surface is not perfectly smooth. The most common imperfections are natural small indentations formed during cultivation. These are different from artificially inflicted scratches and are known as 'blemishes.' While minor blemishes may not be very noticeable when worn, larger ones may require creative solutions during processing, such as concealing them with metal fittings or placing them on the inconspicuous back side.

White South Sea pearl and Akoya pearl differ in the radiance they exhibit. Pearls are formed through the layering of thousands of nacreous layers, causing interference of light. This interference gives rise to the luster known as 'Luster.' White South Sea pearls have a soft, luxurious glow, exuding opulence. Their luminosity and size make them stand out, earning them the nickname 'Queen of Pearls.'

White South Sea pearl oyster is cultivated in equatorial seas like Oceania and Southeast Asia. A notable feature is its thick and substantial nacreous layer. In White South Sea pearl cultivation, a nucleus is placed at the center, and the nacreous layer is wound around it, excluding the organic and prismatic layers beneath.
The nacreous layer consists of thousands of incredibly thin crystalline layers, each about 0.3 microns or 0.0003mm thick. This stacked structure generates brilliance from both internal and external sources, defining the unique character of pearls.

Tahiti Pearl

The Black-Lipped Pearl Oyster inhabits a wide area spanning about 30 degrees north and south of the equator. The main production areas include tropical to subtropical regions near the equator in the South Pacific, such as French Polynesia (Tahiti), the Cook Islands, Fiji, and Australia. Approximately 95% of the production of Black-Lipped Pearls comes from Tahiti, which is why they are also known as Tahitian Pearls. They are also cultivated in Okinawa Prefecture, Japan. These mother oysters prefer areas with suitable tidal flows and clean seawater in the lagoons surrounding islands or atolls. Over an average period of 4 to 5 years, the Black-Lipped Pearl Oysters grow to sizes ranging from 10 to 20 cm.

Tahitian pearl have a higher tendency for deformity compared to pearls from other oysters, such as Akoya pearl. Consequently, while there are semi-round and round variations, a rich variety of shapes is observed, including tear-drop-shaped drops and circle shapes with distinctive lines.

The sizes of Tahitian pearl range from approximately 7mm to 18mm, with the mainstream typically falling between 10mm and 13mm. In the case of necklaces, the most popular sizes often involve a gradient arrangement, starting with smaller pearls at the ends (e.g., 8mm-10mm or 9mm-11mm) and gradually increasing in size towards the center.

Tahitian Pearl, produced by the black-lipped oyster, display a diverse array of colors due to pigments like red, yellow, and green. Despite the name "black-lipped oyster" and the association with black pearls, observing a Tahitian Pearl necklace under bright light reveals each pearl encapsulating multiple colors, such as red and green. These vibrant hues are the inherent and captivating characteristics of Tahitian Pearls. With colors ranging from red and green to orange and pistachio, the infinite variations are among the most enchanting features of Tahitian Pearl.

As pearls are harvested from the sea, it's only natural for them to bear imperfections, and Tahiti Pearl, in particular, are known for their abundance of natural blemishes. Even in cultured pearls, being gems nurtured by nature, the surface is not perfectly smooth. The most common imperfections are natural small indentations formed during cultivation. These are different from artificially inflicted scratches and are known as 'blemishes' or 'blemishes.' While minor blemishes may not be very noticeable when worn, larger ones may require creative solutions during processing, such as concealing them with metal fittings or placing them on the inconspicuous back side.

Through the combination of pigments, a diverse surface color is achieved in pearls. As light refracts, reflects, or transmits within the nacreous layers, interference of light occurs, giving rise to a mystical iridescence. The amalgamation of these interference colors creates the unique luster in pearls that we perceive as 'Luster.'

In the cultivation of Tahiti Pearl, there is a spherical substance at the center called the 'nucleus,' around which the nacreous layer is wound. The organic and prismatic layers, located beneath the nacreous layer, are not included in the winding process.

The nacreous layer is composed of thousands of incredibly thin crystalline layers, each measuring about 0.3 microns or 0.0003mm, stacked on top of one another. This structure generates the brilliance from both internal and external sources, defining the distinctive character of pearls.