Pearls are pearly organic gems.

- How it's formed : A foreign body comes into contact with the mantle of a mollusk, which contains nacre-secreting cells. Layer by layer, the nacre gives rise to a natural pearl... sometimes commonplace, sometimes exceptionally beautiful.

- Hardness: On a scale of 1 (dry soap) to 10 (diamond), pearls range from 2.5 to 4. Despite its relatively low hardness, pearl is nonetheless very resistant.

- Pearl care: We recommend cleaning with a soft cloth soaked in lukewarm, slightly soapy water. It's also advisable to wear it only after applying creams and perfumes, as it doesn't appreciate chemicals. In fact, once the pearls have been pierced and mounted in a necklace, chemicals can damage them by penetrating between the pearl layer and the core.

Fine pearls and cultured pearls: treasures of the seas

A natural or fine pearl is one formed without human intervention. According to historians, this precious intruder has been found in the Persian Gulf, Chinese and European rivers and Sri Lanka for thousands of years, right up to the New World with Christopher Columbus in the late 15th century, who discovered pearls in Venezuela and Panama. Today, it is extremely rare. It was only around 1900 that cultured pearls were invented by Kokichi Mikimoto, who understood the mechanics of their formation. Cultured pearls are also natural, but man has helped nature to finish its work: in the case of fine pearls, the foreign body was accidentally lodged in the mollusc. In the case of cultured pearls, man is responsible for this encounter with the mollusc, controlling every stage of the pearl's growth. The intruder is replaced by a round mother-of-pearl nucleus of varying diameters.

Portrait of a pearl of many reflections

Cultured pearls come in many varieties, depending on their origin and the mollusks from which they are extracted. There are 2 main types of pearl: saltwater and freshwater. Seawater pearls include Akoya, Tahitian and South Sea pearls. These are born in oysters. Freshwater pearls, on the other hand, come to life in giant mussels.

- The Akoya pearl: cultivated in Japan, China and Vietnam, it appeared in the early 1900s. It is the most popular pearl among the general public. Most Akoya pearls are creamy-white, passing through yellow and then pinkish or light gray. Their diameter generally varies between 6 and 10 mm.

- The pearl of the South Seas: usually from Australia, Indonesia and the Philippines, but also cultivated in Thailand and Myanmar, it first appeared in the 1950s. Most of the time, the color of this pearl ranges from creamy-white to gold. It is the largest pearl known: its size ranges from 8 to 18mm, and sometimes larger.

- Tahitian pearl: mainly cultivated in French Polynesia and off the Cook Islands, it first appeared in the 1960s. Its color ranges from gray to black, green to bluish purple, and it can display a unique metallic sheen. Its usual size ranges from 8 to 16 mm in diameter.

- Freshwater pearls: Unlike the above-mentioned examples of sea-grown pearls, freshwater pearls are cultivated in rivers and lakes. Unlike other cultured pearls, the mollusc of a freshwater pearl can produce several pearls simultaneously, making it more affordable than others. Freshwater pearls are found in China, Japan and the United States. They come in a wide range of colors. They first appeared in Japan in the 1930s and in China in the 1970s. They range in size from 2 to 13 mm. While saltwater cultured pearls are the result of an implantation of a piece of mantle combined with a mother-of-pearl core used to form the heart of the future pearl, freshwater cultured pearls don't need a core, so their mother-of-pearl layer is thicker. They are mainly produced from a piece of mantle grafted into a mollusc. China is the world's largest producer of cultured pearls. It is estimated that only 10% of the pearls produced are of gem quality and can be exploited at Jewellery. This shows that the work put in by man and the mercy granted by nature are not always enough to create the sumptuous pearls showcased by jewellers. It's a time-consuming process, requiring a great deal of patience on the part of pearl farm workers. These pearl marvels, the fruit of chance and nature, require many months, sometimes years, of growth before being released from their shells. But what a fabulous sight when the result is perfect!

There are also other types of pearls. These include:

- Blister pearls: these "ampoule " pearls form a solid core inside a mollusk. Unlike other pearls, the part facing the shell has no mother-of-pearl and is flat.

- Keshi : These "poppy seeds" are so-called natural pearls from the South Seas and are baroque (irregular) in shape.

- Mabé : assembly made of half a mother-of-pearl core, which also makes it a flat pearl.