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Posted on 06 May 2017

Conch pearls: what are they and why are they so rare?
Prized for their beautiful colours and unique flame effect, we find out what it is about conch pearls that makes them so elusive - and expensive.

Group of pink conch pearls  photo from Jewellery Editor

Among the rarest and most expensive type of pearl in the world, conch pearls are in demand once again thanks to the resurgence in popularity of natural pearls of all varieties and a renewed appreciation of their uniqueness. In this in-depth article you will find out everything you need to know about these precious little treasures of the sea.

What are conch pearls?

Pretty and pastel-hued, a conch pearl is a calcareous concretion produced by the Queen conch (pronounced “conk”) mollusc, which is a large, edible sea snail. Most often pink in colour and normally oval shaped, the finest examples display a wave-like “flame” structure on their surface and have a creamy, porcelain-like appearance and unique shimmer.

Unlike pearls harvested from oysters, conch pearls – like other naturally occurring pearls, including the Melo and Giant Clam – are non-nacreous, which means they are not made of nacre, the substance that gives traditional pearls their iridescent lustre. Therefore, they are not technically a pearl and are not considered to be “true pearls”, although they are still referred to as such.

The majority of pearls today are cultivated by inserting an irritant into the mollusc and managing its progress, but a conch pearl is a completely natural phenomenon, with no intervention from man.

Harvested by teams of fishermen, a single, elusive conch pearl is found in every 10-15,000 shells, although less than 10% of these are gem quality. This, together with its unusual colour, makes the conch pearl extremely desirable.

Queen conches are harvested by teams of fishermen in the warm tropical waters of the Caribbean, from the Yucatán all the way up to Bermuda (Image featured in The Pink Pearl, courtesy of Susan Hendrickson).

A 3.75-carat conch pearl is set en tremblant inside a Calla Lily by AENEA alongside pink diamonds, white diamonds, pink sapphires and tsavorites in white and pink gold and palladium (POA).

Antique Tiffany pink conch pearl pendant necklace that opens to reveal a 23.50 oval-shaped pink conch pearl
Bought by Henry Walters in 1905, this Tiffany pendant necklace features a remarkable 23.50-carat pink conch pearl as the centrepiece and is housed at the Walters Art Museum in Baltimore.

How are conch pearls formed?

It is believed that a conch pearl is formed when an irritant, often a broken bit of shell, enters the Queen conch, around which a calcareous concentration forms. These concentric layers of fibrous crystals build up around the irritant, in the same way as kidney stones grow in humans.

Unlike oysters, which can be prized open to reveal the exact location of a pearl, no-one knows precisely where conch pearls are formed because of their elaborate whorled structure. Grown inside a pearl sac in the orange mantle of the Queen conch, they are normally found at the same time as the meat is cut out of the shell.

Where are conch pearls found?

Found in large groups of up to 200, Queen conches live among beds of sea grass in the warm tropical waters of the Caribbean, from the Yucatán all the way up to Bermuda.

Conch pearls are a beautiful by-product of the fishing industry in this region. Caught primarily for its meat, the Queen conch is eaten throughout the Caribbean and the US, raw in salads or cooked in local delicacies such as chowders and fritters.

Overfishing in many of the locations in which the Queen conch is found has forced all but three conch-producing countries to ban fishing to protect populations, which it is predicted will not recover for decades. This means fewer conch pearls are coming to market.

At one time, Queen conches were also found off the coast of Florida, where it is now illegal to fish them.

Why are conch pearls so rare?

In a world dominated by cultured pearls, natural pearls, formed without human intervention, come with the “rare” tag that makes them infinitely more desirable. Just like gemstones, which are more valuable if they are sold in their natural, untreated state, the exclusivity of conch pearls is partly down to the fact that they are 100% as nature intended. However, there are other factors that contribute to their rarity.

Traditional nacreous pearls, such as South Sea or Tahitian pearls, are formed in bivalve molluscs, which have two shells, hinged in the middle. A conch pearl is formed in a gastropod mollusc, which has a single spirally constructed shell consisting of many chambers.

All pearls are formed when an irritant is trapped within the mollusc, which the pearl grows around, regardless of whether it is nacreous or non-nacreous, like the conch pearl. Because of the make-up of a Queen conch shell, with just a single entrance, it is much more difficult for an irritant to become embedded inside, which is why it has proved almost impossible to cultivate them.

With the probability of finding a conch pearl about one in 10,000 thousand, and with less than a one in 10 chance that the pearl will be gem quality, conch pearls are considered very rare indeed.

06 May 2017 by CLAIRE ROBERTS   Read Entire Article....

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