A Tahitian cultured pearl is a calcareous concretion, often light or dark grey, produced by pearl oysters (bivalve mollusks).
When something penetrates the interior of a bivalve mollusk (a grain of sand, coral dust), the animal, in order to defend itself, surrounds the intruder with a layer of calcium carbonate, also called nacre.
For a long time, pearls were obtained by chance, but from the beginning of the 20th century, they were cultivated. In 1900, a Japanese team discovered a production technique to cultivate pearls.
The pearl oyster Pinctada Margaritifera was known to the Polynesians long before it was used for pearl farming. They used the fruit of this oyster in many ways: for the creation of ornaments or the making of weapons and this for thousands of years. This oyster has the particularity of having black lips and therefore being the only one to give natural colored pearls. However, it was not until the beginning of the 20th century that the first premises of pearl farming appeared.
The grafting of a pearl oyster consists of introducing a nucleus, a perfectly round ball made from a mussel shell, as well as a graft, i.e. a small piece of the mantle of an oyster that has been sacrificed. The pearl oyster will then secrete pearl material that will surround the nucleus in the best of cases! It is important to know that only 30% of the transplanted oysters will produce pearls. And in this 30%, only a few will be of good size and perfectly round.
In the 1960s, pearl farming made its appearance in Polynesia. Jean Domard, head of the fisheries department at the time, began a long-term project by undertaking the first grafting attempts.
The first pearl farm in Polynesia was established on the Manihi atoll in the Tuamotu archipelago in 1968. Jean-Claude Brouillet, a French businessman, arrived in French Polynesia in 1975 and bought the South Marutea atoll in the Gambier archipelago with a view to pearl farming. Brouillet sold his pearl farm in 1985 to Robert Wan, the man who founded Tahiti Perles, the company that produces the most Tahitian pearls in the world.
CHARACTERISTICS OF THE TAHITIAN CULTURED PEARL
When describing a Tahitian cultured pearl, one must indicate its shape, the quality of its surface, its size in mm and finally its color.
Round(R): Almost perfectly spherical. Perfectly round pearls are the rarest and most expensive.
Semi-round(SR) : A pearl that is not perfectly round, but when mounted, appears so.
Semi-baroque(SB) : They can be button, drop, oval or other undefined shapes.
Baroque(BQ) : Without determined shape, irregular and without axis of symmetry.
Circled(CL) : Characterized by one or more concentric beads or grooves around the body of the bead.
ABCD system (Tahitian system). This standard is used in French Polynesia.
- A : one imperfection or group of light imperfections concentrated on no more than 10% of the surface.
- B : a few light imperfections concentrated on no more than 30% of the surface.
- C : light imperfections concentrated on no more than 60% of the surface.
- D: light and deep imperfections concentrated on no more than 60% of the surface or light imperfections on more than 60% of the surface.
- With more than 60% imperfections, the pearls are not acceptable in jewelry.
Tahitian cultured pearls range in diameter from 7.5 to 16 and up to 18 mm. It takes 2 to 3 years to get a medium caliber pearl, and up to 5 years for larger calibers.
The color palette of Tahitian pearls varies from white to the deepest charcoal gray, passing through all the grays, greens, eggplant, blue.
These colors are natural and vary according to the origin of the graft introduced at the same time as the nucleus but also according to the breeding or the lagoon. They are not a criterion of quality and everyone can choose according to his taste.