Australian South Sea Pearl

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South Sea Pearls


Understanding South Sea Pearls

South Sea pearls are the largest and most lustrous pearls in the world. They are famous for their size, colour and thick nacre coating. The main South Sea pearl producing countries are; Australia, Tahiti, Indonesia, Phillipines and Myanmar.

Of the South Sea pearl producing countries Australian Pearls are the largest, rarest and considered the most luminous pearls in the world. They are known as the 'Queen of Pearls'.

The largest pearl producing mollusc in the world is known as the
Pinctada maxima or silver / gold lip" oyster. It is found mainly in the region of North Western Australia where it can grow on average up to 30cm in size. Variations of this mollusc are found in the other south sea producing countries. This giant mollusc produces a correspondingly large pearl between 9 to 18mm, and on rare occasions 18mm+. It deposits thick layers of nacre than most other pearl producing molluscs. Australia provides the perfect natural environment for these giant shells as the waters are pollution free, miles away from any industry and are continually replenished with huge tides. Together with these factors the industry is protected by government controls which ensure the pearl beds will remain abundant and healthy for the future


In nature a pearl is born when a foreign particle makes it way into the host oyster. As a form of defense the oyster begins to secret nacre until the 'intruder' is completely covered in layers of this thick, lustrous substance.

Today, with a little help from man the process is exactly the same however, the foreign object is a nuclei made from the shell of a freshwater oyster. It is carefully inserted into the oyster and immediately returned to its natural environment to continue growing for many years until it is the right time to remove.

The larger the pearl the oyster produces, the more valuable it is in the trade. Farmers hope that their entire crop turns out with these large pearls that are perfectly round. However, as it is a natural product there are many varying environmental factors which effect the production. The likelihood of producing a perfectly round, large pearl that is beautiful and blemish free decreases. That is why a perfectly round South Sea pearl is considered to be so precious. When you have a necklace composed of these perfectly round pearls it is an investment beyond comparison. The photograph below shows the varieties of South Sea pearls that are available from white, gold, black to multicolor strands.

There are a few major countries which produce the fine necklaces which consumers know as South Sea pearl strands. Below is a listing of these countries and the range of colors that each country is known for. Geography, weather, ocean conditions and slight variations in the species of oysters that produce South Sea cultured pearls can all contribute to a pearl's colour.

There are many species of molluscs which live all over the world. The oyster (mollusc) which produces the South Sea pearl is known as Pinctada maxima or Silver Lip Oyster. It is the largest oyster in the world capable of cultivating a pearl. The larger a pearl is, the longer it has to cultivate in an oyster; adding to its rarity. Because the Pinctada maxima oyster lives and grows its pearls in the wild, its production is limited. This is the single most important factor which contributes to the rarity of South Sea pearls making them the "Rolls Royce" of cultured pearls. Before a South Sea pearl oyster begins cultivating a pearl, a mother of pearl bead implant is inserted into the oyster to begin the pearl forming process. This can be seen in the photograph below and to the right.

The chart below illustrates the range of South Sea pearl shapes. Again, rounder pearls are most valuable. Circle pearls or ringed pearls are the least valuable pearls. Baroque pearls can be as lustrous and beautiful as round pearls and as the large sized baroques are becoming very rare they command high prices in the market. As you move from left to right in this South Sea shape chart, the pearls become less valuable within the wholesale trade.

A perfectly round South Sea pearl when measured with a calliper has a variation in its circumference that is less than 2%. For example, if, what appears to be a perfectly round south sea pearl, is 12 millimeters measured in its shortest diameter and 12.1 millimeters in its longest diameter the circumference variation is 1% (12 divided by 12.1 = .99). Or you can refer to this pearl as 99% round. Rounder pearls are most valuable.

A pearl that appears to be perfectly round whose circumference variation is 2% or more. If a pearl has a diameter of 12 millimeters in its shortest length and 12.3 millimeters in its longest length, the variation in its circumference is 2.5% (12 divided by 12.3 is .975). Or you can refer to this pearl as 97.5% round. The fact that it has a variation in circumference that is over 2.5% means that it is semi round. Semi round pearls are the most valuable shaped pearls second only to round pearls. It is very common to see a south sea pearl necklace that is composed of round and semi round pearls. The reason for this is that it is very difficult to make a necklace where all of the pearls are perfectly matched in body colour, shape, overtone, quality and luster. Semi round south sea pearls can be 20% less than round pearls.

A pearl that has a variation in circumference that is approximately 20%. For example, a pearl that measures 12mm by 12.5mm. These button pearls are often used in jewelry pieces and earrings because they are not round or semi round. It is common to have a pearl and diamond earring set with button pearls. Buttons that appear to be round are called "Tall Buttons." A talented jeweller can set buttons into jewellery and make the pearls appear round; especially the tall buttons. Some people insist on making earrings or other jewellery with only perfectly round pearls, but because these round pearls are rare and reserved for necklaces, they are expensive. Buttons can be half the price of round pearls. We often make south sea button necklaces where we drill a full necklace of south sea button pearls through their shortest diameter so they sit like disks on a strand. These necklaces are not as valuable as round or semi round necklaces but have an expensive look to them at a fraction of the price of round necklaces. A bargain shopper might purchase a button strand where all the pearls are "tall buttons" because when viewed from a distance, they appear to be round.

The next criteria needed to understand South Sea pearls is size. South Sea pearls are most notable for their large sizes. This is because the oysters (Pinctada maxima(silver lipped) from Australia, Pinctada maxima (gold lipped) from both Indonesian and Myanmar and Pinctada margariftifera (black lipped) from Tahiti are the largest species of mollusc capable of producing a pearl. Whereas the Akoya oyster which produces the Japanese Akoya pearl produces a maximum size of 10mm. The Pinctada maxima oyster is three times the size of the largest Akoya oyster.

The white South Sea pearls from Australia range in size from (9 to 20mm), note that any pearls above 18mm are considered extremely rare. The black South Sea pearls from Tahiti (the primary island of French Polynesia), size range is 8mm to 15mm and the golden pearls from Indonesia and Myanmar range in size from 8mm to 13 and 14mm. Australia being the only country that produces the largest white pearls as the average size of their harvest is greater than any other country.

Please see the chart below to view the size range of white South Sea pearls from Australia and black South Sea pearls from Tahiti. Although it is possible to get pearls smaller than 10mm and larger than 16mm in South Sea, they are scarce.

Most of the necklaces that are composed using cultured South Sea pearls have a size variation of 2 to 3 millimeters within each necklace. This is because there are not enough South Sea pearls produced each year to make uniform necklaces exclusively that match in luster, body colour, shape and overtone. A pearl company, must have a selection of a minimum of 10,000 pearls (lot) to compose a range of necklaces that is properly matched. This necklace will be graduated is size. For example, one might compose a necklace of 33 pearls which is 16 inches long and graduates from 10 millimeters up to 13 millimeters as the center pearl. The fewer the pearls in a beginning lot, the less likelihood there is of composing a necklace where the pearls have a similar luster, body colour, shape and overtone. How well a south sea necklace is composed is based on the quantity and uniformity of pearls available and the skills of the company. Therefore, a good strand should be well matched in colour, quality, lustre and shape.

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