Tagged with 'Freshwater pearls'

Here is a simple question. How many freshwater pearls are there in this image ?

Pearls have fascinated us for hundreds of years with their colours, shapes and diversity. Despite our long love story with pearls, our general knowledge of these pretty and precious gems is still relatively poor. A simple test of our understanding is whether we can explain the difference between a freshwater and a saltwater pearl…

Saltwater pearls include Akoya pearls historically from Japan, Tahitian pearls from French Polynesia and South Sea pearls from Australia and Indonesia, whilst Freshwater pearls today originate mainly from China. The difference between saltwater and freshwater pearls is not their geographic origin, however, but in the mollusks in which they originate.

Saltwater pearls are found in oysters that live in saltwater oceans and seas, whilst freshwater pearls are found in mussels that live in freshwater rivers, lakes and ponds.

Both saltwater and freshwater pearls are formed with a similar process. All pearls are formed as the mollusk secretes layers of a protective iridescent substance called nacre around an irritant. In natural pearls an irritant such as a parasite enters the mollusk, whereas with cultured pearls, this irritant is introduced intentionally by man. Experts define both saltwater and freshwater pearls as ‘pearls’ for they have concentric layers of nacre.

Both freshwater and saltwater pearls make beautiful jewellery. Their unique characteristics of each variety make it not too difficult to distinguish a freshwater pearl from a saltwater pearl by looking at its natural colour, its shape, its size and whether the pearl has a bead nucleus inside. Metallic pastel colours, for example, are a clear sign that a pearl is of freshwater origin. A knowledgeable eye might look at the drill hole of the pearl to determine if there is a shell bead nucleus inside.

Continual advances in pearl farming techniques, for example with the introduction of round beaded nuclei to help make larger round freshwater pearls, are making some of these differences harder to identify. With some significant differences in price between freshwater and saltwater pearls, it is always advisable to purchase pearls from a reputable jeweller.

PS The answer above is that there are 5 cultured freshwater pearls in the image above, the rest are all cultured saltwater pearls.

Have you wondered how long it takes to grow a real cultured pearl? Is it a month, a year or perhaps longer? The answer? Of course it depends...

The delicate process of culturing pearls

Pearl farmers start the process of producing a cultured pearl in an oyster or mussel by delicately implanting a small piece of mantle tissue, the part of a mollusc that secretes shell-like material. Farmers might also add a bead of shell, typically from a freshwater mussel to help provide a nucleus for the pearl.

If this complex procedure is successful, the mollusc will start to deposit iridescent layers of nacre, slowly creating a cultured pearl.

One of the first factors that influences the growth of a cultured pearl is how quickly the mollusc recovers from the implantation procedure itself. This is a particularly sensitive time. Before the growth stage of a pearl, the operated mollusc will need care and attention from the pearl farmer.

Image: Cultured pearls

In the case of Japanese Akoya oysters, this care period lasts up to six weeks, as much as three months for a large Tahitian and South Sea oyster, but for Freshwater pearl mussels this care period can be as short as about two weeks.

If you are interested in the differences between the different types of pearls, learn more in our Buying Guide here.

Nacre growth rates

Once the mollusc has recovered, it is returned to the pearl farm population, where the main period of growth of the cultured pearl will take place.

Depending on the type of mollusc, the water cleanliness, temperature and the time of the year will all influence the rate at which the mollusc deposits its nacre to grow a cultured pearl.

During this time, the molluscs will be regularly inspected by a pearl farmer, checked for sickness and cleaned of parasites. The farmer will also closely monitor environmental factors such as water temperature, food quality and any risks of pollution.

The growth rate of nacre can vary widely with around 0.3mm of nacre a year for Akoya pearls, up to 2mm a year for Tahitian and Australian South Sea pearls and as high as 5mm per year for Chinese freshwater pearls.

Nucleation is also a factor in a pearl's size

For non nucleated pearls, which did not initially have a bead of shell implanted, a simple rule is that the longer a pearl is grown in the mollusc the larger the pearl.

Typically, non nucleated Chinese freshwater pearls can quickly grow to maturity over periods as short as 6 months, reaching sizes up to 9mm in diameter within 24 months.

Image: An operation by a pearl farmer to culture a pearl

This simple rule may not be true for nucleated pearls, however, as their size is also influenced by the diameter of the implanted shell bead and how many culturing operations the oyster has had.

Typically, an Akoya pearl will grow between 10 to 14 months before reaching a size of up to 9mm in diameter, a Tahitian pearl may grow for 18 to 24 months to reach a size of 10mm and a South Sea pearl will grow between 2 and 3 years to reach diameters of up to 15mm.

For nucleated pearls, the thickness of the nacre is often a reliable measure of how long each pearl has been cultured and its quality.

A complex partnership with nature...

So to answer the question, there are many factors that determine the size of a real cultured pearl and how long it will take to grow in an oyster or mussel. It is an amazing and complex process that relies on the skill and expertise of the pearl farmer and their partnership with nature.

If you are interested in learning more about the different qualities of a pearl, why not read our Buying Guide to Pearl Grading.

There are many ways to wear pearls and choosing the right length of necklace for your intended look is one of the first decisions to make.

The sautoir necklace, also known as a pearl rope necklace, is usually 95 cm in length or more. Worn as a single strand, the pearl sautoir can reach the waist and has a vintage style reminiscent of the 1920s, swinging round the necks of girls dancing the Charleston.

But the sautoir is also one of the most versatile rope pearl necklaces as it can be looped around the neck up to three times or can be worn knotted at the front. Recently the pearl sautoir has seen a revival with the trend for layering jewellery, perhaps worn with freshwater pearls of a different shape and colour, semi-precious stones or chains.

Certain clasp designs will also allow a sautoir to be twisted and worn like a short thicker necklace.

One of the most popular items at Winterson, the pearl rope necklace is a lasting addition to any jewellery box.

Fashioned with oddly shaped pearls, we have just introduced our first Keshi pearl necklace and matching Keshi pearl bracelet to Winterson.

The word keshi or keishi means ‘poppy’ in Japanese. This pretty word perfectly captures the shining lustre, orient and baroque shape of Keshi pearls, which lend themselves to distinctive jewellery.

Keshi are thought to form naturally in a saltwater oyster, as a piece of trapped tissue, shell or a micro-organism causes the growth of a baroque pearl. With no implanted bead nucleus, they are composed entirely of nacre and this gives rise to their beautiful shine.

In recent years with the growth of the cultured pearl industry, Keshi pearls have been produced in saltwater oysters by accident when the inserted nucleus separates from its tissue implant. The term Keshi is also widely used by producers of Chinese cultured freshwater pearls to describe baroque pearls that are produced spontaneously in the mussel after the first harvest of pearls.

Let us know what you think.  We hope you like them !

The historic Star Ferry has ploughed its way across Hong Kong harbour since the late 1880s. The crossing is named by National Geographic Traveler as one of their 50 Places of a Lifetime.

When the sun is shining, the sea turns a petrol green colour and with that magnificent skyline, there can be few better ways to get to work in the morning or places for buying pearls.

For the last four days, Hong Kong has been host to the largest Spring Jewellery Show in Asia, with more than 30,000 buyers and suppliers attending from around the world – a record attendance despite recent times.

In pearl terms, Hong Kong has grown to be one of the most important pearl trading centres in the world and this is one of the key dates in the annual calendar for buying pearls. It is hard to comprehend the size of the pearl industry until confronted by more than 10,000 square metres of pearls for sale at this Jewellery Show.

The new season’s freshwater pearls from China are available to the market for the first time and prestigious pearl famers such as Robert Wan from Tahiti and Paspaley from Australia offer their pearls at auction to a select specialist group of buyers.

Pearl prices are beginning to rise again. Demand for these incredible gems is increasing, particularly from customers in India and China, whilst production over the last two years has been reduced as pearl farmers have weathered the global crisis.

This is particularly true of larger Freshwater, Akoya, Tahitian and South Sea pearls and higher grade quality pearls are in much shorter supply now. With minimum lead times of 18 months to over 3 years for farmers to increase their pearl harvest, it is likely that this trend will continue for the foreseeable future, especially for the premium grade pearls.

It is a good time to buy pearls and we will have many beautiful pieces of pearl jewellery to show you at Winterson over the coming months.

If you hear a pearl described as real or natural, remember that there is a significant difference in meaning.

A natural pearl is a real pearl formed in a wild mollusc living in its natural habitat and without any human intervention. Cultured pearls are also real pearls, but the pearl farmer stimulates the development of the pearls in the mollusk.

Natural pearls have been collected and used in jewellery for centuries. Until the introduction of techniques for culturing pearls in the early 20^th century, the world’s main natural pearl fisheries could be found in the Persian Gulf, the Gulf of Mexico, the Mannar Straits between India and Sri Lanka, and off the coast of California.

The image of a diver searching for pearls in azure blue tropical waters is a symbolic one, as today there are few fisheries left due to over-fishing, pollution and competition from the cultured pearl industry.

In response to increasing demand and limited supply, the value of rare natural pearls has been rising steadily over the last ten years.  A natural pearl necklace can be priced at between 100 and 10,000 times the value of a cultured pearl necklace of the same size, weight and lustre.

Freshwater pearls are cultured around the world, including in countries such as Japan and the USA. Over the last twenty years the Chinese have perfected the production of culturing pearls in freshwater mussels, which are farmed in lakes and streams.

Most freshwater pearls available today are produced in China and make really lovely pieces of jewellery. The best quality freshwater pearls sit comfortably alongside the finest Akoya, Tahitian and South Seas pearls and can also offer great value.

 

The triangular-shaped shell mussel Hyriopsis cumingii is used to produce up to 50 freshwater pearls in each mussel, depending on the size and quality desired. In contrast to saltwater pearl culturing, freshwater pearls generally need no nucleus, with the pearl only being produced by the mussel once a piece of nacre-producing tissue is inserted into the mussel to create the pearl sac.

 

The size of these cultured freshwater pearls can vary widely from tiny poppy seed pearls to more regular pearls between 6 and 12mm. Very recently developed grafting techniques have also introduced a nucleus to the mussel to culture even larger freshwater pearls.

 

The placed position of the nacre-producing tissue and the shape of a nucleus in the mussel can produce different shapes of pearls such as round, semi-round, oval, button, baroque, coin and drop shapes.

 

As well as being capable of producing consistently high quality pearls, freshwater mussels cleverly produce a dazzling rainbow of colours including shades of white, apricot, lavender and pink Freshwater pearls.

 

With this quality and diversity of freshwater pearls, we can offer a range of fashionable and classic freshwater pearl necklaces, freshwater pearl earrings and jewellery that we hope you will love.

Following the invention of the cultured pearl, a revolution began to take place in the world of pearls. Pearl diving and over-fishing in the late 19th century had driven prices of natural pearls soaring.

The advent of techniques for culturing pearls in saltwater oysters brought these fabulous gems within the reach of many, without depleting further the world’s natural mollusc beds. The method used for the creation of a cultured pearl is still widely used today.

A small round bead of shell material from a mussel and a piece of nacre-producing tissue from another oyster is inserted into a saltwater member of the Pintadine shellfish family. This highly skilled procedure is called a graft.

The nacre-producing tissue forms a small pearl sac around the bead and then gets to work covering the irritant with layers of nacre. Once the process has started, the pearl farmer has little control over of the final size, shape and colour of the pearl produced.

Once grafted less than 5% of these Pintadine shellfish, commonly referred to as oysters, go on to produce the best quality cultured pearls. Each pearl is unique and individual.

Today these grafting techniques are used in countries such as Japan, Indonesia and Australia to produce a wide variety of cultured pearls in both saltwater and freshwater molluscs.

This amazing diversity has inspired new directions of pearl jewellery and fashion beyond the classic white pearl necklace.

The next articles in this series will look in turn at the many different types of cultured pearl, in particular Freshwater, Akoya, Tahitian and South Sea pearls.

A natural pearl might start with an itch, although most pearl experts now agree that the 'grain of sand' is nor more than a myth.

When a small seed of material such as a parasite becomes trapped within an oyster or mussel's shell, nature gets to work. The shellfish slowly deposits layers of organic material called nacre around the source of its irritation.

Nacre is made from two forms of calcium carbonate called Aragonite and Calcite, which are found in the interior lining of shellfish that is often called ‘mother-of-pearl’. These are linked together by a little organic protein called Conchiolin, which is identical to that found in human hair and fingernails. Together these substances form the nacre.

Over time, layering of this nacre by the shellfish forms a smooth surface around the foreign material slowly transforming it into a beautiful pearl, unique in its shape, size and colour. The difference from one pearl to another lies in the shape and placement of crystals of Aragonite and Calcite that are being held in place by Conchiolin.

In our next articles we shall look at the differences between natural and cultured pearls.