The mysterious beauty and watery origins of pearls have inspired symbolism and mythology for centuries. Many cultures associate this gem with the moon. Often used in bridal jewellery, pearls are symbol of love and purity and were traditionally given as a wedding gift. Pearls are also said to symbolise tears, to provide fertility, and to ward off evil. Born in oceans, lakes and rivers, this June’s birthstone has always embodied the mystery and life-sustaining nature of water.
What is a Pearl?
A pearl is a hard object grown in either the soft mantle tissue or the gonad of a living shelled mollusc.
Natural Pearls vs Cultured Pearls
The most valuable pearls occur spontaneously in the wild, but are extremely rare. These wild pearls are referred to as natural pearls. Perfectly created by nature and requiring no human assistance to enhance their beauty, natural pearls form around a microscopic irritant in the bodies of certain molluscs.
To find a wild pearl, hundreds of pearl oysters or mussels must be gathered, opened and killed. Before the cultured pearl, this was the only way pearls were obtained, and why they fetched such extraordinary prices in the past.
Unlike natural pearls, the growth of cultured pearls requires human intervention and care. Today, most of the molluscs used in the culturing process are raised specifically for that purpose, although some wild molluscs are still collected and used. Cultured pearls are the result of the deliberate insertion of a bead or piece of tissue that the mollusc coats with nacre. They can be divided into two broad categories; pearls grown in salt water and pearls grown in fresh water. While both are beautiful, pearls grown in salt water are considered to be more valuable.
Types of cultured Pearls
The classic, white, round saltwater pearls, originally only cultivated in Japan, a similar oyster is now used for pearl culture in China.
Freshwater pearls are the most commonly produced pearls and they are one of the most popular types. They come in the widest variety of shapes, sizes and colours of all cultured pearl types.
Considered by many to be the most exotic of all cultured pearls, Tahitian pearls are cultivated primarily around the islands of French Polynesia. Tahitian pearls are sometimes referred to as “Black Pearls”, however they are very rarely black. They usually come in shades of green, purple, aubergine, blue, grey, silver or peacock (a mix of several shades)
South Sea Pearls
These enormous pearls are grown in the largest shell used in pearl production. Australia, Indonesia, and the Philippines are leading sources of these saltwater cultured pearls. South Sea cultured pearls can be white to silver or golden, depending on the type of oyster. Their limited critical growing conditions plus large size and thick nacre, due to a long growth period are all factors contributing to their value. These are the most valuable pearls farmed.
What are Keshi Pearls?
Keshi are pearls that form without being intentionally nucleated, formed by accident in a mollusc undergoing pearl cultivation. The word Keshi means “poppy seed” in Japanese.
What is Mother of Pearl?
Also known as nacre, is an iridescent layer lining the inner shell of some mollusc species.
What are Mabé Pearls?
Also called composite blister pearl, is cultured by inserting a half dome nucleus on the inside of the oyster shell, opposed to a cultured pearl which is growing in the soft parts of the oyster.
Value factors of pearls
The qualities that determine the overall value of a natural or cultured pearl are size, shape, colour, lustre, surface quality, nacre quality. For jewellery with two or more pearls, the fact that all the pearls are matching is also a value factor.
The most familiar colours are white and cream (light yellowish brown) or pink. Black, grey, and silver are also relatively common, but the palette of pearl colours extends to every hue. The bodycolor is often modified by additional colours called overtones, which are typically pink, green, purple, or blue.
Pearls occur in a wide variety of shapes, many of which are quite unique and interesting.
Some shapes are distinctively unique to certain species of molluscs. Pearl shapes are divided in 3 broad categories; spherical shapes (round or near round), semi-baroque (symmetrical) and baroque (irregular). Within these categories, pearls can be classified into 7 shapes:
- Round: Perfectly round pearls are the rarest and most valuable shape. They are perfectly spherical.
- Near-round: These pearls are not perfectly round, they are usually slightly flattened or elongated.
- Oval: Like their name indicates, these pearls are oval shaped.
- Button: Button pearls are flattened round, making them resemble a button.
- Drop: Pear or teardrop shaped.
- Circled: These pearls are characterised by concentric ridges, or rings, around the body of the pearl. They a are usually symmetrical shape and are not really a “true” shape but more of a special characteristic within a given shape. They are referred to as “circled drop”, “circled oval” or “circled button”.
- Baroque: Baroque pearls are non-symmetrical and irregular with unique and interesting shapes.
A pearl’s size is measured according to its diameter in millimetres. Depending on the type of pearl the sizes range from 1 millimetre or less, to as much as 20 millimetres for large South Sea Pearls. Typically, the larger the size of the pearl, the greater its value (when all other factors are equal). Larger pearls are grown in larger oysters and require much more time to develop.
Natural pearl diving decimated shell populations around the world. When a new pearl bed was discovered, it was quickly fished until nearly all shells were depleted. But this all changed with the technical innovation and vision of one man near the turn of the twentieth century—Kokichi Mikimoto, the father of the cultured pearl.
As pearl producers have always understood, pearls can only be grown in pristine waters. Pearls are a “sustainable” product because maintaining a proper environment for growing pearls requires a carefully protected ecosystem. Pearl molluscs assist in the work as they are filter feeders and clean their habitats of small particles of debris.
Pearl molluscs have a pair of ganglia in lieu of a central nervous system. This means they can feel no pain, no emotion and have no ability to suffer. Most molluscs receive only one or two beads, although some operations that specialise in very small pearls may implant up to five. The operation is performed by highly skilled and experienced technicians, and takes less than a minute. Harvesting a pearl does not kill the oyster, and pearl farmers are extremely carful when placing a bead or mantle inside it, not to harm their oysters. Depending on the types of pearls and a few other factors, pearls are usually harvested after 1 to 3 years.
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