Bijoux Pearls Guide to Pearls

Have you ever found yourself drawn to someone who was wearing pearls? You might be captivated by someone wearing diamonds, but it’s the diamonds that sparkle.  When a woman wears pearls, it is she who shines.  Pearls complement a woman in whatever she is doing.  They become part of her, not something worn by her.  With quiet grace and seductive allure, pearls help a woman convey who she is, or who she wants to be.

From People and Pearls: The Magic Endures
Aurum Press


Did you know?

Did you know that pearls are known for "not stealing the show?" Instead they enhance the natural beauty of the wearer. Diamonds are typically "attention takers," causing people to focus on the diamond's radiance rather than on the wearer.


Pearls as a Source of Purity

A pearl is pure because it is one of nature’s wonders.  Pearls have always been seen as natural representatives of life milestones.  Some of the milestones in which pearls have been tradionally given include birth, baptism, christening, first communion, bat mitzvah, sweet sixteen, graduation, twenty-first birthday, engagement, marriage and anniversaries. 


What is a Pearl?
A pearl is one of nature’s jewels.  A pearl naturally formed is a quirk of nature. A pearl is naturally formed when an irritant enters and lodges in the mantle tissue or either a salt water or freshwater oyster or mollusk.  In order to protect itself the oyster will seal the irritant in a coating of conchiolin which triggers the production of nacre. 


Nacre is a combination of crystalline and organic substances.  Nacre is the same material found in the inside of oysters and mollusks and is also known as Mother of Pearl.   It is the nacre which gives luminosity to each pearl.


The oyster will then produce numerous coatings of nacre around the irritant until the layers harden to form a pearl.  The pearl forming process can take a number of years.  Pearls are now produced using the cultured production method.  This means that an irritant (a bead for saltwater oysters or a piece of shell for freshwater mollusks) is deliberately placed to initiate the pearl production process.   This modern method of pearl production is called the cultured pearl method.


Cultured formed pearls versus Natrually formed Pearls

In naturally formed pearls the irritant will get into the tissues by chance.  And by chance a perfectly round pearl will be formed.  In reality natural pearls and perfectly round natural pearls formed entirely by chance are extremely rare, making up around only 5 – 10% of worldwide pearl production.


In cultured pearls a small bead or live mantle tissue from another mussel or oyster is inserted into the mussel or oyster to initiate the pearl forming process.  The mussel or oyster than forms the pearl through a natural process.  Through this method perfectly round pearls can be formed on a larger scale than would occur naturally.


Many of the pearls offered for sale are cultured pearls.  Around 90% of the worlds pearl supply is manufactured.  Pearls formed in salt water pearls naturally are highly rare purely because a natural pearl is formed entirely by chance.  A pearl in effect is a one of act of nature and cultured pearls are the manufacturing process which has enabled suppliers to meet the demand for pearls.


Freshwater and SaltWater Pearls


Freshwater Pearls

Freshwater pearls come in a variety of shapes and sizes ranging in colours from white, light pink to dark purple.   Shapes can range from nearly round to perfectly round, baroque, and other shapes.  Freshwater pearls are grown predominately in China but some are still grown in Japan.  Freshwater pearls are grown in freshwater oysters which live in freshwater rivers and lakes.

Freshwater Cultured Pearls, are grown in mussels which are farmed in freshwater areas. and grown in mussels.  The cultivation process for freshwater pearls usually produces around 20 or more pearls for one mussel.   Freshwater pearls are made of solid nacre meaning that they are very durable.


Where Do Freshwater Pearls Come From?

Although the traditional source of pearls has been saltwater oysters, freshwater mussels, which live in ponds, lakes and rivers, can also produce pearls.


China has harvested freshwater pearls in the form of Mabe pearls since the 13th century, and has now become the world leader in freshwater pearl production. The first record mentioning pearls in China was from 2206 BC. The United States was also a major source of natural freshwater pearls, from the discovery of the America, through to the 19th century.  Natural pearl production decreased significantly because of over-harvesting and pollution which reduced the number of pearls in the US significantly.

Saltwater Cultured Pearls are grown in oysters and farmed in saltwater areas.  The cultivation process for saltwater pearls produces one pearl per oyster.  Because of this, salt-water pearls are more expensive than freshwater pearls.

Tradionally before the advent of cultured pearl production, saltwater pearls were formed naturally in the Persian Gulf, the Red Sea and the waters of India and Japan.  Natrually formed pearls are still found but the yield is only 5 to 10% of world production, not enough for the worldwide demand for pearls.

Saltwater pearls are produced in South East Asia (Thailand, Indonesia and the Philippines), The South Pacific (Australia and Tahiti) for south sea pearls and Tahitian pearls.

The three most common types of saltwater pearls are Akoya pearls, Tahitian pearls, and South Sea pearls.

The Differences Between Saltwater Pearls and Freshwater Pearls

The thickness of the nacre coating various for pearls.   Freshwater pearls are entirely made of nacre all the way through due to the procedure used to produce them.

Akoya pearls have a nacre coating of about 0.5mmm, Tahitian pearls about 2 to 3 mm and South Sea pearls from 2 – 6mm.

Freshwater pearls are all pearl - a south sea pearl would have to reach 18 to 20 mm in diameter to rival the amount of nacre a freshwater pearls has.  Generally for all pearls, the larger the size, the more expensive. 

Saltwater pearls are expensive because not as many are produced, salt water oysters produce one cultured pearl per oyster, freshwater mollusks produce up to 20 freshwater pearls per shell.  Freshwater pearls now rival the shape, size,  look and feel of saltwater pearls such as South Sea pearls or Akoya but for a fraction of the price. 

Pearls and Pricing
Pearls come in a range of shapes, styles, colours, quality and pricing. Our take on the pricing of different types of pearls is that because of the rarity of some types of pearls (South Sea, Tahitian) there will be a price premium placed on these types of pearls. Freshwater pearls are grown in larger quantities simply because the mollusk can produce more pearls per shell, around 20 as opposed to 1 pearl in a saltwater oyster.  Also shape, how long it takes to culture a pearl, surface quality, colour also each play a part in the price of pearls. 

How Long to Grow a Pearl?
South Sea pearls and Tahitian pearls (salt water pearls) take 2 to 3 years to grow. Japanese Akoya pearls take around 18 months to 2 years.   Freshwater pearls take from 3 to as long as 5 to 6 years to grow.  The longer the cultivation time, the larger the size of the pearl.

Freshwater pearls can now grow up to 16mm in a perfect round  rivaling the size and shape of the more expensive saltwater pearl (south sea pearl or Tahitian pearl).

The cultivation of freshwater pearls has now reached the same standard of pearls grown in Saltwater areas.

Pearl Size 

Cultured pearls are measured and sold according to millimeters. Freshwater pearls can range in size from 4mm to 11mm but are now being grown larger.  Usually the larger and rounder the pearl the more expensive the pearls will be.  Sizes 7 to 7.5mm are the most common size.  Saltwater pearls (South Sea/Tahitian) can be grown up to 20mm.


Pearl Shape

Freshwater pearls come in all shapes from button, rice, oval, almost round,  tear dropped shaped, perfect round, potatoe (ringed), baroque.  All pearl shapes and colours are attractive and choice  of pearl shape and colour depends on the personal preference of the wearer.


Shapes can be formed by using different sized nuclei for the mussel or oyster to form nacre around and will generally take on the shape of what ever has been inserted into the oyster.  Round pearls account for 2% of the annual freshwater pearl yield.


When China first began to produce cultured freshwater pearls the pearls came out rice shaped and small.   There is now more of am emphasis on producing rounder shapes particularly near round or perfectly round shapes.  Most pearls produced are oval, button or drop shaped (60%) with semi baroque and baroque shaped pearls accounting for the remaining 38% of pearl production.  


Because pearls come in such a variety of colours and shapes, pearl jewellery in all its shapes and colours and variety is beautiful and suits everyone.


Baroque Pearls are irregular or potatoe shaped pearls. Baroque pearls are not round or near round but can be nugget shaped, potatoes happed, slightly oval shaped.  We would say that baroque pearls represent the true natural shape of pearls.  Pearls come in a variety of shapes so it is usual to own more than one piece of pearl jewelry perhaps a piece made of round pearls and other jewellery featuring baroque or other types of pearls.


Baroque pearls are irregular shaped pearls and come in a range of colours.  Potatoe pearls (off round pearls with sometimes a ring around the centre) are in this category.  The baroque shaped pearl is growing in popularity (currently representing 38% of pearl production) because there are so many shapes, sizes and colours that can make beautiful jewellery.


Oval pearls are egg shaped pearls and make beautiful bracelets and necklaces.  Oval pearls also come in a wide range of sizes.


Button pearls are round on one side and flat on the other, hence the name.  They come in a range of sizes and can be used to make children’s jewellery. We also stock button pearl rope necklaces.


Mabe pearls are raised round on one side and flat on the other.  Mabe (pronounced mah-bay) are grown in the inside of the oyster’s shell rather than within the tissue.  Mabe pearls make beautiful pendant jewellery.


They come in colours between black and navy with irredescent sheen. They are quite unusual but eye catching especially when hung from a silver or white gold chain.


Teardrop shaped pearls are highly suitable for earrings and pendant drop necklaces.


Rice pearls are fat rice shaped and come in a number of colours.


Seed pearls are small (from 2 – 3 mm) and have the appearance of seeds.  Usually used to decorate material such as wedding and bridal dresses.


Pearl Type

Pearl type refers to the type of shell a pearl comes from and where it is grown.


Akoya pearls

Akoya Pearls.  Akoya pearls come from the Akoya oyster. Akoya pearls are nearly always perfectly round and come in a creamy white colour but can range from light pink to light gold.  Production of Akoya pearls is mainly found in Japan with China, Korea, Hong Kong and Sri Lanka also producing Akoya pearls.  Akoya pearls have a milky sheen luster.   Akoya pearls are very suitable for children’s jewellery and wedding or bridal jewellery as the milky white composition is very satiny looking.


Blister Pearls

Blister pearls are irregular shaped pearls and come in a variety of shapes and colours.  Blister pearls are formed when the pearl gets embedded in the inside of the shell of the oyster (the part which is padded by mother of pearl). The pearl will then form into a blister shape as it has been formed out of the soft shell of the oyster. 


Coin Pearls.  Coin pearls are cultured pearls that have been manufactured into a coin shape.  They are flat and sit easily on the neck or wrist.  They come in white, pink and off white colour tones.


Kasumiga Pearls also known as Kasumi Pearls are grown in Lake Kasumiga north of Tokyo. The mussels they are grown in are a cross between Japenese and Chinese freshwater mussels.  Kasumiga pearls range from gold to white, to purple to pink with the pink tones being the most common colour. They are large pearls measuring 11 – 16mm in diameter.

Keishi Pearls

Types of pearls that grow naturally in the soft tissue or adductor muscle of cultured pearl bearing mollusks and come out in a variety of shapes. Keishi forms are formed as an accident of the cultured freshwater pearl production process.  Usually found in the second or third pearl harvest and caused by natural irritants.  For Akoya pearls (which has only one harvest), Keishi pearls are sometimes formed.


Blister Pearls

Blister pearls are highly irregular shaped pearls and come in a multitude of shapes and colours. Blister pearls are found in contemporary fashion pearl jewellery. Blister pearls are formed when the pearl gets embedded in the mother of pearl shell (i.e. in the inside shell of the oyster) and the pearl forms into a blister shape.


Tahitian Pearls

Grown in pearl beds in Tahiti, Tahitian pearls are usually dark (silvery black to mid black) and can grow up to 12mm and more.  Generally the rounder and larger the pearl, the more expensive it will be.  Tahitian pearls are grown in Saltwater pearl beds. 


South Sea Pearls

Come in very large sizes from 13 mm to 20mm.  South Sea pearls are grown between the northern coast of Australia and the southern coast of China.   The South Sea extends from South East Asia, Thailand, Burma, Indonesia and the Philippines through to Northern Australia and the South Pacific.  The oysters that south sea pearls come from can grow to 12 inches in diameter hence the very large sizes of south sea pearls.  Because of the large size of the pearl, a large bead to start the nucleation process can be inserted into the pearl meaning large pearl sizes.   


South sea pearls are grown in saltwater pearl beds in the South Sea pacific area.  South see pearls typically come in white, silver and light gold and are quite large.  South sea pearls take around 2 years to grow as opposed to Akoya pearls which take 8 – 10 months and freshwater pearls 7 – 8 months.


South Sea Shell Pearls

Not a real organic pearl but can be used instead of the South Sea Pearls because of their size.  Sizes usually range from 12mm to 16mm which would cost s fortune for South Sea pearls of the same size.

South Sea Shell pearls are man made manufactured pearls. The shells of oysters and mussels are ground and then manufactured using a man made pearl making process to make the south sea shell pearl. South sea shell pearls are perfectly round, come in sizes up to 20mm and in a range of colours.  They are an alternative to the natural south sea pearls which normally retail at around £60 to £200 per pearl.