Natural pearls are very precious. Just like in old times, they are only brought to the surface from the depth of the ocean by pearl divers, a risky activity still today. Pearl lovers pay prices of several 10,000 Euros per pearl for the rarest and finest qualities.
The people of the Arabian Peninsula already dived for oysters as far backas in early Neolithic times. This is shown by a pearl that French archae- ologists discovered in a grave in the emirate Umm al-Qaiwain in 2012. Experts dated its origins to somewhere between 5547 and 5235 BC. The oldest written reference to a pearl is made in the Chinese history book of Shu King dating back to 2206 BC: “King Yu was given pearls from the Hwai River as tribute”. During all antiquity, whether in the Arabian world, Persia or India, pearls were highly treasured. The most precious gem of organic origin was seen as a symbol of good fortune, beauty and wealth. Therefore it’s little wonder that pearls are the stuff of many legends. The Romans, for example, believed pearls to be the fruit of the love goddess Venus, the Greeks thought them to be the dew of the moon, and the Kurdish mystics interpreted them as an embryo slumbering at the bottom of its mussel uterus.
Fashion comes and goes, but pearls are timeless and always en vogue. The value of a pearl is determined by various factors: size, shape, colour, quality of surface and lustre. Depending on the type of pearl, the colour spectrum ranges from white, pink, red, orange, gold, bronze, copper, silver and silvery grey all the way to black. Experts use two technical terms when describing the iridescence of a pearl: lustre (outer surface sheen) and orient (inner sheen). The more intense and clear its lustre, the higher the quality of a pearl. When look-ing at the surface of a high-quality pearl you should be able to recogniseyour own reflection. Orient describes the glow that comes from the inside of a pearl. These refractions are caused by the numerous layers which make up a pearl. In Europe pearls are divided into three shapes: round, symmetrical and baroque. The Americans, however, further break down the shape using the terms semi-round, semi-symmetrical and semi-baroque. While salt- water cultured pearls from Japan must have a perfect round shape, this is rather the exception for South Sea cultured pearls.
cultured pearls are an important economic factor in some countries
Unlike natural pearls, cultured pearls are always created by artificiallyplanting a foreign body into the oyster, mussel or snail. In China,
Japan, Australia and the South Sea, and here in particular in Indone- sia, the Philippines and French Polynesia, the production of cultured pearls is a vital part of the economy. For years, the growth rate is increasing. This is due to two factors: The rising demand for pearl products and the fact that natural pearls are increasingly rare to find.About 100 years ago, three Japanese gentlemen independently fromeach other looked for ways to cultivate pearls. The most famous was Kokichi Mikimoto, who went down in history as the father of the cultured pearl trade. For the production of cultured pearls, host mus- sels are collected and kept on artificial banks under ideal conditions (temperature, water quality). The creation of a cultured pearl starts by implanting a pearl nucleus. This complex ‘surgical procedure’ on the mussel is performed by highly qualified and often also highly paid experts. From this moment, it will take two to five years during which the oyster covers the pearl nucleus layer by layer with nacre. However, growing pearls is unpredictable. A mere 4 to 5% of cul- tured pearls end up with the ideal round shape. Most pearls have so-called ‘baroque’ shapes: elongated, flat, knotty, drop-shaped, etc.
This type of saltwater cultured pearl is grown around the southerly islands of Japan in the Pinctada martensii oyster.
These are saltwater cultured pearls grown in French Polynesia aroundTahiti. The rarest and most expensive black Tahitian pearl has a glow- ing lustre with a peacock feather green colour.
South Sea cultured pearls
This pearl is grown in a huge cultivation area spanning from Northern Australia, Thailand, Taiwan, the Philippine Islands, the Indonesian Ar- chipelago, French Polynesia all the way to Burma. The biggest production of South Sea cultured pearls is found in the Northwest of Australia, where they only use the Pinctada maxima oyster to grow pearls.
Freshwater cultured pearls
Today, these are mostly nucleus-free cultured pearls from freshwater growing areas.
Creation of a pearl
To put it bluntly, a pearl is nothing else but a parasite or foreign body sealed off by nacre (mother-of-pearl). Marine and freshwater mus- sels and snails are able to produce pearls as a defence mechanism against a threatening irritant that has entered the shell. Genuine pearls grow without any human interference. In earlier times the people believed that grains of sand, which had gotten into the shell, triggered the mollusc’s protective response. Today scientists believe that epithelial cells of the mussel, which end up in its deeper mantletissue through invading parasites or other injuries, are responsible forthe creation of a pearl. There, these cells form a cyst that is subse- quently covered with layers of mother-of-pearl. This will seal off the foreign body, killing it, and the mussel is no longer threatened by the invader.