A selection of conch pearls of various sizes, shapes and hues.

The shell of a queen mollusc, from which the conch pearl origanates.

As we have seen in previous posts, the market for natural gems is rising like never before.  Untreated precious stones are reaching record prices at auction and collectors are rediscovering the charm and marvel of gemstones previously considered a little obscure.  Riding high on the crest of this wave (pun intended) is the elusive conch pearl (pronounced conk).  Thanks to the creation of a cultured pearl market in the first half of the 20th century, pearl prices suffered a slump until the beginning of this one.  The destruction of pearls’ natural habitats, consumer uncertainty at not knowing where to safely deposit money and the rise of the millionaire class in the East have all contributed to the multiple price increase of natural pearls.

Conch pearl, rose gold and diamond bee ring by Cindy Chao.

Conch pearls are in a class of their own.  They are not ‘true’ pearls as generally thought of by the general public because they are not made of layers of nacreous material like ‘real’ pearls.  They do not come from oysters, but from the queen conch mollusc, which is a large, edible sea snail.  But they are formed in the same way as pearls: a foreign body lodges itself inside a mollusc, which then secretes a hard substance around it on order to reduce the irritation.  So technically they are pearls.  With conch pearls, however, the secretion around the irritant is non-nacreous, nacre being the substance that gives traditional pearls their characteristic lustre.  However, both are composed of calcium carbonate.  Hence conchs are included in the list of organic gems.

Why are they so highly prized? Only one answer: rarity.  And they are far rarer than natural pearls.  One single pearl is found in every 12000 shells; of these, only 10% are gem quality.  Conchs cannot be harvested- they can be found in almost any part of the queen conch snail, so it is not entirely understood how they are formed.  In contrast, cultured pearls have been refined to a fine art and the irritant is always inserted into the oyster in the same place in order to produce the pearl.  Pearls are also the only gem that nature produces that requires no further human treatment- no heat enhancement, cutting or polishing.

Looking and feeling like beads of fine porcelain, the colour range of conch pearls is from brown, yellow, beige and ivory through to white and pink.  The rarest and most desirable colour by far is pink.  It has been observed that the healthier the reef where the queen mollusc is farmed the more intense the pink.  The most sought after shape is a perfect oval, although irregular, baroque specimens have been used to great effect in jewellery.  Conchs also display a gemmological feature known as chatoyancy, a flame like pattern of light within the gem caused by the fibrous nature of the material. 

It is unusual to find conch pearls larger than 2-3mm; anything over 10 carats is exceptional.  One of the most important conch pearl jewels in existence is a necklace created by Tiffany and Co. in 1905 for the American art collector and philanthropist for his niece Laura Delano.  It is a typical Belle Epoque necklace, a chain of diamonds suspending a diamond cage, inside which a 23.50 carat pink conch pearl sits.  The necklace is extremely valuable: exceptional pearls of this size and value can easily reach $15000 a carat.  If you are prepared to compromise on quality, you should still be prepared to shell out in the region of $5000.

An exceptional conch pearl and diamond ring by David Morris.  If you look closely you can see the flames on the surface of the stone.

Diamond, conch pearl and coloured gem earrings by Anna Hu.

Conch pearls have risen in popularity recently in line with natural pearls.  They are particularly treasured and sought after in Japan after a huge push by Mikimoto (the Japanese cultured pearl pioneers) to educate the public on them.  In the United Kingdom, they are a particular favourite at David Morris, where they have been used to great effect.  They also seem to be particularly popular amongst artist jewellers such as Sarah Ho, Anna Hu and Wallace Chan, all of whom specialise in creating spectacular, one off jewels.  To which this most rare of gems lends itself perfectly.

A conch pearl of great importance, a 23.50 carat specimen in a necklace made for the philanthropist Henry Walters by Tiffany and Co. in 1905.