The Pearl

Pearl is an intruder which has skilfully forged itself a place amongst the marvels of nature. Chance clearly has a part to play in everything...

For thousands of years, pearls have sparked admiration and desire.

The creation of a pearl is an accident caused by nature.
An intruder, a simple piece of dirt, a tiny parasite which penetrates a mollusc. If the mollusc is unable to remove this, then it will protect the intruder by covering it in nacre, which gradually transforms it into a pearl.

Pearls have a long lifetime, which begins inside a mollusc before finally being much coveted by the holder.
It uncovers its beauty in various different forms, colours, and iridescences (also called orient), sizes, and shades.
The many varied faces of pearls in addition to the special attention which they require throughout their lifetime bolster their unique and magical character.

Small identity card of an atypical gemstone

Pearl is a natural opalescent gemstone.

- Formation :

A foreign body comes into contact with the outer layer of a mollusc, which contains cells secreting nacre. Layer upon layer, the nacre begins to create a natural pearl. Often simple, and sometimes quite exceptionally beautiful.

- Hardness :

On a scale of 1 (talc) to 10 (diamond), pearls measure between 2.5 and 4. Despite its relatively weak level of hardness, pearls are however very resistant.

- Care :

It is recommended that you use a soft cloth soaked in tepid and gently soaped water to clean pearls. It is additionally recommended not to wear until after having used cream and perfume, as pearls are not favourable to chemical products. Once pearls are pierced and placed on an item of jewellery, such chemical products can ruin them as they penetrate between the layer of pearl and the core.

Fine pearls and cultured pearls : treasures of the sea

A pearl which is formed without any human involvement is called a natural or fine pearl. According to historians, these precious intruders were first discovered in the Persian Gulf, rivers in China and Europe, and in Sri Lanka several years before the New World as discovered by Christopher Columbus who then discovered pearls in Venezuela and Panama. This type of pearls is today very rare.

It was only around 1900 that cultured pearls were invented by Kokichi Mikimoto, who understood the way they were formed by nature.

Cultured pearls are still natural, but humans simply help nature to complete its job : for fine pearls, the foreign body found molluscs by chance. For cultured pearls, humans facilitate this meeting with the mollusc, and control each stage of the growth of the pearl. The intruder is replaced by a round nacre core, with different diameters.

Portrait of a pearl with various reflections

Cultured pearls come in various shapes and sizes, depending upon where they are from and the molluscs n which they are formed.
Two main categories of pearls exist : salt-water pearls and freshwater pearls.
Amongst the salt-water pearls, there are Akoya pearls, Tahitian pearls and South Sea pearls. These originate from oysters. Whilst freshwater pearls originate from giant mussels.

- Akoya Pearls

These are cultivated in Japan, China and Vietnam and appeared in the early 1900s.
They are the most widely known to the general public. The majority of Akoya Pearls are creamy white, with some having a hint of yellow, rose or light grey. In general, their diameter measures between 6mm and 10mm.

- South Sea Pearls

These generally originate from Australia, Indonesia and the Philippines but are also cultivated in Thailand and Myanmar and appeared in the 1950s. In most instances, these pearls range from creamy white to golden. These are the largest known pearls, with a calibre varying between 8mm and 18mm, and sometimes more.

- Tahitian Pearls

These are primarily cultivated in French Polynesia and off of the Cook Islands, and appeared in the 1960s.
The colour of these pearls ranges from black to various shades of green, bluish-purple and can even have a unique metallic reflection.
The usual size of these pearls varies between 8mm and 16mm in diameter.

- Freshwater Pearls

Contrary to the examples previously mentioned regarding pearls cultivated in salt-water, freshwater pearls are cultivated in rivers and lakes.
Unlike other cultured pearls, molluscs in which freshwater pearls originate can product several pearls simultaneously, making them more affordable than other types.
These pearls can be found in China, Japan and the USA. They are available in much varied colours. They were first discovered in Japan in the 1930s and in China in the 1970s. The size of these pearls varies between 2mm and 13 mm.

Whilst pearls cultured in salt-water originate following the placement of a piece of mantle shell combined with a core of nacre used to form the heart of the future pearl, those cultured in freshwater do not require a core and their layer of nacre is, therefore, much thicker. These are primarily produced solely from a piece of the mantle shell of a mollusc.

China is the largest producer of cultured pearls in the world.
It is estimated that only 10% of pearls produced are of gemstone quality, and therefore of quality acceptable for use in jewels. This shows that the work undertaken by humans and the grace afforded by nature are not always sufficient in creating the sumptuous pearls on show in jewellers’ windows. This is indeed a very lengthy task for which workers on pearl farms must be extremely patient. Such sumptuous pearls, which are a result of fate and nature, require many months, and sometimes years of growth before they can be released from their shell. However, when the result is spectacular it is certainly worth the wait !

There are other types of pearls. Amongst these are :

  "Blister" pearls : these "blisters" form a solid core within a mollusc. Unlike other pearls, the part which faces the shell does not have any nacre and is entirely flat.

  Keshi pearls : these "poppy seeds" are natural pearls which originate from the Southern Seas and are baroque shaped (irregular).

  Mabe pearls : these are composed of a half-nucleus of nacre, which also makes them flat pearls.

The value of pearls

According to the GIA (Gemological Institute of America), there are seven key factors to be taken into account when estimating the value of a pearl :

  Size (measured in millimetres)
  Shape (round, flat, baroque, circular, pear-shaped, rice-grain, etc.)
  Colour (dominant colour, orient or iridescence)
  Lustre (the intensity of light : a key factor in establishing the value of a pearl)
  Surface quality (imperfections, blemishes, etc.)
  Nacre quality (thickness of the layers of nacre, opacity, uniformity, etc.)
  Matching (or when pearls are placed side by side how much they resemble each other)

For Philippe Tournaire, the colour and orient of a cultured pearl are the most important. The orient gives "the impression of being able to go into the colour". Jewellers are sensitive to pearls which stand out from the others due to their orient which may be unique and found nowhere else.

Below are a handful of terms used by professionals when describing the colour of a pearl :

  Aubergine : this term is used for Tahitian purple-tinted pearls.
  Peacock : for a Tahitian cultured pearl with a dominant grey-green or dark blue-green colour with a hint of pink-purple.
  Pistachio : used for yellow-green cultured Tahitian pearls.
  Golden : pearls which are cultured in the South Seas with a yellow colour with delicate hints of orange or green.

Treated and imitation pearls

Some cultured pearls such as Akoya or South Sea pearls often undergo treatment such as bleaching, colouring or radiation. Often x-rays are used to determine whether this type of treatment has been used. The true colour of a pearl can additionally be observed from a hole pierced into a pearl, which indicates the true colours.

There are an infinite number of imitations, however, none of these are able to match the beauty and unique aspect of cultured or fine pearls.

Amongst these factors, is the essence of the orient :
In the 17th Century, a French rosary created a pearl by-product :
Created on the basis of a glass marble which was covered in fish scales and varnish, he managed to create a very convincing imitation natural pearl. This method continues to be used albeit after some modernisation in the technique. The truth is, imitations are all too often too perfect to claim to have been created by nature !

Down the centuries, pearls have always and continue still to be a key element of jewellery. Once they are worn, in a ring, a pendant, or necklace, and so on, pearls give off all of their splendour and are seen in their best light. They are a dreamy invitation to plunging in the sea and freshwaters from across the globe, which are a true dive into the beauty of nature. This "sublime accident", as Philippe Tournaire likes to call it, is a genuine source of inspiration.
So come and discover this marvel through Philippe Tournaire’s workshops !
We will take you on a true journey throughout the improbably and charming world of a foreign body which is known to us one and all !
The pearl is a masterpiece of unique creations, in its very own image