Pearl
Pearls are organic substances and each one is unique. Pearls have been coveted through the ages for their beauty as symbols of wealth and status.
A Chinese historian recorded the oldest known reference to a pearl in 2206 BC and pearls have been found in aboriginal grave mounds. The Renaissance kings and queens were renowned for their love of pearls: King Henry VIII adorned his robes with them and his daughter Mary Tudor owned the most famous pearl in history – La Peregrina (‘The Pilgrim’). The most desired natural pearls came from the Persian Gulf, the waters of Ceylon (now Sri Lanka), Chinese rivers and lakes and some rivers in Europe.
Pearl formation process begins when a foreign body enters a mollusk (usually an oyster or mussel) and is coated with nacre as a natural defence. This creates a pearl. Due to many factors the natural pearl market declined after 1900. Today 99% of pearls are cultured and are grown around the world in saltwater oysters and freshwater mussels.
There are eight types of pearl: natural, south sea, akoya, Tahitian, freshwater, keshi, seed and mabé.
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Properties
Pearl is 3 on the Mohs scale.
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Colour
Pearls can be white, cream, yellow, black, blue, pink and green.
Pearl colour is always a combination of colour and overtone. The overtone is translucent ad changes or
add depth to the body colour of the pearl. Pink overtone is the mot popular.
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Birthstone and Anniversary stone.
Pearl is the birthstone for July. Pearl is traditionally given as a gift for a 30th wedding anniversary.
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Cultured Pearls​
Records show that the Chinese were farming freshwater cultured pearls as far back as the 1200’s. Pearl culturing is an adaptation of the natural pearl formation process. The pearl formation process starts when a foreign body enters and irritates a mollusk (usually an oyster or mussel) and the pearl coats the foreign body with nacre. When pearls are cultured humans insert the foreign body to stimulate pearl growth themselves. Humans imitate and control the natural process and also control the environment of the mollusk shells growing the pearl.
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Types of cultured pearls: Akoya, South Sea, Tahitian and Freshwater.
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Akoya: ​Produced by Akoya (pinctada fucata) oysters on saltwater pearl farms in Japan, China, Vietnam. The akoya pearl was the first cultured pearl, as far back as 1893. The akoya pearl is very popular as it is usually white with a rosé overtone. Akoya oysters live in waters up to depths of 5 meters and in mild to warm temperatures of around 68°F. Akoya oysters generally produce the smaller pearls on the market and tend to produce pearls ranging from 2mm-10mm with an average size of around 6.5mm. The akoya oyster shell produces the most consistently round pearls of all the oyster producers.​
South Sea: ​Produced by the pinctada maxima ​oyster in saltwaters principally in Australia, Indonesia and the Phillippines. There are two types of pinctada maxima – gold or silver lipped. South Sea pearls are usually considered the most valuable pearls produced, as they reach the biggest sizes. The south sea pearl is usually between 9mm and 20mm, with an avaerage size of 13mm. The south sea pearl also tends to have thicker nacre meaning they possess a unique satiny luster. The gold lipped oysters produce golden coloured pearls and the silver lipped produce silvery-white pearls.
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​Tahitian: Tahitian pearls have been cultured since the 1960’s. They are produced by the pinctada margaritifera oyster in saltwaters principally off the coasts of French Polynesia and the Cook Islands. The pinctada margaritifera is a black lipped oyster and they produce black pearls. Truly black pearls are very rare, most Tahitian pearls are charcoal coloured with purple or green overtones. Tahitian pearls range from between 8mm – 17mm, with the average being around 10mm in diameter.
Freshwater:​ Freshwater pearls are the products of mussels in the non-salt waters of lakes and rivers, mainly in China. The main producer is known as the ‘triangle shell’, its proper name is the Hyriopsis Cumnigi. Although China produces the most freshwater pearls, small crops are also produced in the US and Vietnam. Freshwater pearls range from between 2mm-13mm, with the average being around 6mm-10mm. Generally speaking, only around 2% of freshwater pearls are spherical.
