Unlike most gemstones that are found within the earth, pearls have an organic origin - they are created within certain species of oysters. Some pearls are found naturally in molluscs that inhabit the sea, or freshwater such as rivers. However, many pearls today are cultured, raised in oyster farms that sustain a thriving pearls industry. Pearls are made mostly of aragonite, a relatively soft carbonate mineral that also makes up the shells of molluscs.
A pearl is created when a very small fragment of rock, sand grain or parasite enters the oyster. It irritates the mollusc, which responds by coating the foreign material with layer upon layer of shell material.
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A pearl begins its life when a foreign object enters the body of an oyster and cannot be expelled. |
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To protect its soft body against intrusion, cells within the oyster secrete a smooth and hard substance, called nacre, around the irritant. |
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After two or three years of depositing layer upon layer of nacre over the irritant, if the oyster survives and conditions are just right, a beautiful pearl is formed. |
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Pearls possess a uniquely delicate translucence and lustre that place them among the most highly valued of gemstones. The colour of the pearl depends both on the species of mollusc that produced it and its environment. White is perhaps the best-known and most common colour. However, some pearls also come in delicate shades of black, cream, grey, blue, yellow, lavender, green and mauve.
Japan is perhaps the most famous area for cultured pearls. Everyone familiar with jewellery has heard of Mikimoto pearls, named after the creator of the industry, Kokichi Mikimoto. Some cultured pearls are bread in large oyster beds in Japanese waters. An irritant, such as a tiny fragment of mother of pearl, is introduced into the fleshy part of the oysters. highly trained technicians open the live oysters carefully, then surgically implant the irritant in each one. The oysters are regularly feed and grow in mesh bags submerged beneath the water. Pearl technicians check water temperatures and feeding conditions regularly, for generally between two to three years before harvesting the oysters to remove their pearls. Cultured pearl industry is also carried out in Australia and equatorial islands of the Pacific.
Unlike imitation pearls, no two cultured pearls are ever exactly alike. Each has its own unique combination of size, shape, lustre and colour. The art of assembling pearls in a necklace, a pair of earrings or other jewellery calls for refined skills in blending similar pearls together so that they match.
Drill holes must be made with care and precision. An inexperienced operator can split or ruin the pearls with careless handling. A hole drilled even slightly off centre can ruin a necklace or piece of jewellery that depends upon the symmetrical assembly of its pearls. This stage in the preparation of cultured pearls for jewellery is a very delicate operation.
In the end, despite painstaking care, only 20% of the oysters will yield marketable cultured pearls. Dealers must harvest about 10,000 pearls to find enough that are so closely matched that they can be assembled to make a single necklace.
In recent years great progress has been made in the production of fresh water pearls, which until recently where often described as rice crispy pearls due to their very irregular shape. The pearl farmers have gradually improved the techniques and technologies used and as a result are now able to produce almost round material in sizes of over 10mm. However to date they are still unable to replicate the deep lustre which can be found on the better quality Japanese cultured pearl.
The main differences between saltwater (Akoya) cultured pearls and freshwater cultured pearls are that the akoya pearls are nucleated with an irritant such as a small piece of mother-of-pearl shell, or a bead. The freshwater variety is non-nucleated, and so is solid pearl, thus unlike the akoya pearl the nacre will never wear off. Freshwater pearls are also much more plentiful than the akoya pearl, due to less pollution and the fact that a fresh water mussel is able to produce in excess of 10 pearls, where as its saltwater counterpart is only able to produce one in its lifetime, which is why saltwater pearls are somewhat rare and demand a higher price over their fresh water cousins.
When buying cultured pearls there are a number of factors to take into consideration. The information below and images are provided courtesy of the Cultured Pearl Information Centre and will be a useful guideline, but a visit to us will help to explain how to balance a number of quality and size variables to get the best selection available within a certain price range.
Decide upon the length of necklace you require, and whether it needs to be a single strand or a multi strand: -
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"Collar" 12-13" |
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"Choker" 14-16" |
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"Princess" 17-19" |
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"Matinee" 20-24" |
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"Opera" 28-34" |
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"Rope" is over 45" |
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Other important factors to consider
1) Lustre -The combination of surface brilliance and a deep-seated glow, the lustre of a good-quality pearl should be bright, not dull. Your reflection should be seen clearly on the surface of a pearl. Any pearl that looks too chalky or dull indicates low quality.
2) Surface marks -Cleanliness of the pearl surface refers to the absence of disfiguring spots, bumps or cracks. A pearl with a clean surface will have a higher value than a spotted, bumpy or cracked one.
3) Shape -Since cultured pearls are grown by oysters and subject to the whims of Mother Nature; it is very rare to find a perfectly round pearl. While rounder pearls are more valuable, asymmetrical, or baroque, pearls have a unique charm and are available at a more moderate cost.
4) Colour -Cultured pearls occur in colours from rosé to black. While colour is a matter of preference, rosé or silver/white pearls tend to look best on fair skin tones, while cream and gold-tone pearls are flattering to darker complexions.
5) Size -Measured by their diameter in millimetres, the average cultured pearls sold today are between 7 - 71/2 millimetres. Generally, the larger the pearl, the more valuable it will be.
More delicate than other gemstones and precious metals, cultured pearls need special care to ensure they will remain clean, bright and lustrous for generations to come. Here are some useful tips to help preserve your pearls for future years
1) Do not store your pearls in amongst other gemstones and metal items, as they will become marked.
2) Do not expose your pearls to hairspray, perfume or cosmetics.
3) Do not clean your pearls with any abrasive or acidic cleaning products.
4) Do store your pearls in a soft pouch or silk lined box for protection
5) Do always put on your pearls last, after you have applied all cosmetics, hair spray and perfume in order to minimise contamination.
6) Do keep a piece of silk/chamois or a damp cloth to run your pearls through after wearing to remove any harmful elements.
7) Do have your pearls restrung on fresh silk at least once a year in order to prevent old and contaminated silk from breaking. Make sure to have your pearls restrung with knots between each pearl. This will:-
A) Prevent the pearls from rubbing on each other and causing premature wear.
B) Stop the pearls becoming loose should the silk break.
